Purpose In wireless communication system, use of multiple antennas for different requirements of system will increase the system complexity. However, reconfigurable antenna is maximizing the connectivity to cover different wireless services that operate different frequency range. Pattern reconfigurable antenna can improve security, avoid noise and save energy. Due to their compactness and better performance at different applications, reconfigurable antennas are very popular among the researchers. The purpose of this work, is to propose a novel design of S-shaped antenna with frequency and pattern diversity. The pattern and frequency reconfiguration are controlled via ON/OFF states of the PIN diode. Design/methodology/approach The geometrical structure of the proposed antenna dimension is 18 × 18 × 0.787 mm3 with εr = 2.2 dielectric constant. Three S-shaped patches are connected to a ring patch through PIN diodes. The approximate circumference of ring patch is 18.84 mm and length of patch is 5 mm, so approximate length of radiating patch is 14.42 mm and effective dielectric constant is 1.93. Conductor backed coplanar waveguide (CPW) is used for feeding. The proposed antenna is designed and simulated on CST microwave studio and fabricated using photolithography process. Measurements have been done in anechoic chamber. Findings Antenna shows the dual band operation at 2.1 and 3.4 GHz frequency. The first band remains constant at 2.1 GHz resonant frequency and 200–400 MHz impedance bandwidth. Second band is switched at seven different resonant frequencies as 3.14, 3.45, 3.46, 3.68, 3.69, 3.83 and 3.86 GHz with switching of the diodes. The −10 dB bandwidth is more than 1.4 GHz. Research limitations/implications Pattern reconfigurability can be achieved using mechanical movement of antenna easily but it is not a reliable approach for planar antennas. Electronic switching method is used in proposed antenna. Antenna size is very small so fabrication is very crucial task. Measured results are deviated from simulation results due to fabrication error and effect of leads of diodes, connecting wires and battery. Practical implications The reconfiguration of the proposed antenna is controlled via ON/OFF states of the three PIN diodes. The lower band of 2.1 GHz is fixed, while second band is switched at five different resonant frequencies as 3.27, 3.41, 3.45, 3.55 and 3.88 GHz, with switching of the PIN diodes with all state of diodes and exhibit pattern reconfigurability at 2.1 GHz frequency. At second band center frequency is significantly changed with state of diodes and at 3.4 GHz pattern is also changed with state of diodes, hence antenna exhibits frequency and pattern reconfigurability. Originality/value A novel design of pattern and frequency reconfigurable antenna is proposed. Here, work is divided into two parts: first is frequency reconfiguration and second is radiation pattern reconfiguration. PIN diodes as switch are used to select the
{"title":"A novel S-shaped frequency and pattern reconfigurable patch antenna for 4G LTE, WLAN/Wi-Max application","authors":"Pallav Rawal, S. Rawat","doi":"10.1108/mi-09-2022-0162","DOIUrl":"https://doi.org/10.1108/mi-09-2022-0162","url":null,"abstract":"\u0000Purpose\u0000In wireless communication system, use of multiple antennas for different requirements of system will increase the system complexity. However, reconfigurable antenna is maximizing the connectivity to cover different wireless services that operate different frequency range. Pattern reconfigurable antenna can improve security, avoid noise and save energy. Due to their compactness and better performance at different applications, reconfigurable antennas are very popular among the researchers. The purpose of this work, is to propose a novel design of S-shaped antenna with frequency and pattern diversity. The pattern and frequency reconfiguration are controlled via ON/OFF states of the PIN diode.\u0000\u0000\u0000Design/methodology/approach\u0000The geometrical structure of the proposed antenna dimension is 18 × 18 × 0.787 mm3 with \u0000\u0000εr = 2.2 dielectric constant. Three S-shaped patches are connected to a ring patch through PIN diodes. The approximate circumference of ring patch is 18.84 mm and length of patch is 5 mm, so approximate length of radiating patch is 14.42 mm and effective dielectric constant is 1.93. Conductor backed coplanar waveguide (CPW) is used for feeding. The proposed antenna is designed and simulated on CST microwave studio and fabricated using photolithography process. Measurements have been done in anechoic chamber.\u0000\u0000\u0000Findings\u0000Antenna shows the dual band operation at 2.1 and 3.4 GHz frequency. The first band remains constant at 2.1 GHz resonant frequency and 200–400 MHz impedance bandwidth. Second band is switched at seven different resonant frequencies as 3.14, 3.45, 3.46, 3.68, 3.69, 3.83 and 3.86 GHz with switching of the diodes. The −10 dB bandwidth is more than 1.4 GHz.\u0000\u0000\u0000Research limitations/implications\u0000Pattern reconfigurability can be achieved using mechanical movement of antenna easily but it is not a reliable approach for planar antennas. Electronic switching method is used in proposed antenna. Antenna size is very small so fabrication is very crucial task. Measured results are deviated from simulation results due to fabrication error and effect of leads of diodes, connecting wires and battery.\u0000\u0000\u0000Practical implications\u0000The reconfiguration of the proposed antenna is controlled via ON/OFF states of the three PIN diodes. The lower band of 2.1 GHz is fixed, while second band is switched at five different resonant frequencies as 3.27, 3.41, 3.45, 3.55 and 3.88 GHz, with switching of the PIN diodes with all state of diodes and exhibit pattern reconfigurability at 2.1 GHz frequency. At second band center frequency is significantly changed with state of diodes and at 3.4 GHz pattern is also changed with state of diodes, hence antenna exhibits frequency and pattern reconfigurability.\u0000\u0000\u0000Originality/value\u0000A novel design of pattern and frequency reconfigurable antenna is proposed. Here, work is divided into two parts: first is frequency reconfiguration and second is radiation pattern reconfiguration. PIN diodes as switch are used to select the","PeriodicalId":49817,"journal":{"name":"Microelectronics International","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45936086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Hamzah, M. H. Samat, N. A. Johari, A. Faizal, O. H. Hassan, A.M.M. Ali, R. Zakaria, N. H. Hussin, M. Yahya, M. Taib
Purpose The purpose of this paper is to investigate the structural, electronic and optical properties of pure zinc oxide (ZnO) and transition metal (Tm)-doped ZnO using Tm elements from silver (Ag) and copper (Cu) by a first-principles study based on density functional theory (DFT) as implemented in the pseudo-potential plane wave in CASTEP computer code. Design/methodology/approach The calculations based on the generalized gradient approximation for Perdew-Burke-Ernzerhof for solids with Hubbard U (GGA-PBEsol+U) were performed by applying Hubbard corrections Ud = 5 eV for Zn 3d state, Up = 9 eV for O 2p state, Ud = 6 eV for Ag 4d state and Ud = 9.5 eV for Cu 3d state. The crystal structure used in this calculation was hexagonal wurtzite ZnO with a space group of P63mc and supercell 2 × 2 × 2. Findings The total energy was calculated to determine the best position for Ag and Cu dopants. The band structures and density of states show that Tm-doped ZnO has a lower bandgaps value than pure ZnO because of impurity energy levels from Ag 4d and Cu 3d states. In addition, Ag-doped ZnO exhibits a remarkable enhancement in visible light absorption over pure ZnO and Cu-doped ZnO because of its lower energy region and extended wavelength spectrum. Originality/value The results of this paper are important for the basic understanding of the 3d and 4d Tm doping effect ZnO and have a wide range of applications in designing high-efficiency energy harvesting solar cells.
目的利用密度泛函理论（DFT）的第一性原理研究纯氧化锌（ZnO）和过渡金属（Tm）掺杂的ZnO的结构、电子和光学性能。设计/方法/方法基于Perdew-Burke-Ernzerhof的广义梯度近似，通过应用Hubbard修正Ud=5对Hubbard U固体（GGA-PBEsol+U）进行计算 Zn3d态为eV，O2p态为Up=9eV，Ud=6 Ag 4d态的eV和Ud=9.5 对于Cu3d态为eV。计算中使用的晶体结构为六方纤锌矿ZnO，空间群为P63mc，超晶胞为2×2×2。结果计算了总能量以确定Ag和Cu掺杂剂的最佳位置。能带结构和态密度表明，由于Ag 4d和Cu 3d态的杂质能级，Tm掺杂的ZnO具有比纯ZnO更低的带隙值。此外，与纯ZnO和Cu掺杂的ZnO相比，Ag掺杂的ZnO表现出显著的可见光吸收增强，因为其具有较低的能量区域和扩展的波长光谱。原创性/价值本文的结果对于基本理解3d和4d Tm掺杂效应ZnO具有重要意义，并在设计高效集能太阳能电池方面具有广泛的应用。
{"title":"A DFT+U study of structural, electronic and optical properties of Ag- and Cu-doped ZnO","authors":"N. Hamzah, M. H. Samat, N. A. Johari, A. Faizal, O. H. Hassan, A.M.M. Ali, R. Zakaria, N. H. Hussin, M. Yahya, M. Taib","doi":"10.1108/mi-05-2022-0088","DOIUrl":"https://doi.org/10.1108/mi-05-2022-0088","url":null,"abstract":"\u0000Purpose\u0000The purpose of this paper is to investigate the structural, electronic and optical properties of pure zinc oxide (ZnO) and transition metal (Tm)-doped ZnO using Tm elements from silver (Ag) and copper (Cu) by a first-principles study based on density functional theory (DFT) as implemented in the pseudo-potential plane wave in CASTEP computer code.\u0000\u0000\u0000Design/methodology/approach\u0000The calculations based on the generalized gradient approximation for Perdew-Burke-Ernzerhof for solids with Hubbard U (GGA-PBEsol+U) were performed by applying Hubbard corrections Ud = 5 eV for Zn 3d state, Up = 9 eV for O 2p state, Ud = 6 eV for Ag 4d state and Ud = 9.5 eV for Cu 3d state. The crystal structure used in this calculation was hexagonal wurtzite ZnO with a space group of P63mc and supercell 2 × 2 × 2.\u0000\u0000\u0000Findings\u0000The total energy was calculated to determine the best position for Ag and Cu dopants. The band structures and density of states show that Tm-doped ZnO has a lower bandgaps value than pure ZnO because of impurity energy levels from Ag 4d and Cu 3d states. In addition, Ag-doped ZnO exhibits a remarkable enhancement in visible light absorption over pure ZnO and Cu-doped ZnO because of its lower energy region and extended wavelength spectrum.\u0000\u0000\u0000Originality/value\u0000The results of this paper are important for the basic understanding of the 3d and 4d Tm doping effect ZnO and have a wide range of applications in designing high-efficiency energy harvesting solar cells.\u0000","PeriodicalId":49817,"journal":{"name":"Microelectronics International","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48906158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Purpose The purpose of this paper is to develop a model that allows determining the boron concentration profile in silicon based on duration and temperature of the diffusion process. Design/methodology/approach The model was developed on the basis of the Fick’s second law, which is fundamental for describing the diffusion process. The explicit scheme of the finite difference method was used in the conducted simulations. Results of measurements made using the secondary ion mass spectrometry (SIMS) were used as template dopant concentration profiles. Solution of boric acid in ethanol is the dopant source for which this model was developed. Findings Based on the conducted simulations, it was proposed that besides the influence of electric field of ionized dopants, which is already described in literature, an appropriate factor reflecting the influence of the threshold concentration on the coefficient of diffusion of boron in silicone should also be introduced. Originality/value The developed model enables determination of the boron concentration profile in silicon consistent with the results of SIMS measurements. A factor taking into account the influence of threshold concentration on the coefficient of diffusion was introduced. The influence of concentration of boric acid in the dopant solution on the concentration profile was also considered.
{"title":"Model of boron diffusion in silicon used for solar cell fabrication based on boric acid solutions","authors":"W. Filipowski","doi":"10.1108/mi-07-2021-0065","DOIUrl":"https://doi.org/10.1108/mi-07-2021-0065","url":null,"abstract":"\u0000Purpose\u0000The purpose of this paper is to develop a model that allows determining the boron concentration profile in silicon based on duration and temperature of the diffusion process.\u0000\u0000\u0000Design/methodology/approach\u0000The model was developed on the basis of the Fick’s second law, which is fundamental for describing the diffusion process. The explicit scheme of the finite difference method was used in the conducted simulations. Results of measurements made using the secondary ion mass spectrometry (SIMS) were used as template dopant concentration profiles. Solution of boric acid in ethanol is the dopant source for which this model was developed.\u0000\u0000\u0000Findings\u0000Based on the conducted simulations, it was proposed that besides the influence of electric field of ionized dopants, which is already described in literature, an appropriate factor reflecting the influence of the threshold concentration on the coefficient of diffusion of boron in silicone should also be introduced.\u0000\u0000\u0000Originality/value\u0000The developed model enables determination of the boron concentration profile in silicon consistent with the results of SIMS measurements. A factor taking into account the influence of threshold concentration on the coefficient of diffusion was introduced. The influence of concentration of boric acid in the dopant solution on the concentration profile was also considered.\u0000","PeriodicalId":49817,"journal":{"name":"Microelectronics International","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48795259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhentao Wang, Pai Peng, Sujuan Zhong, Yafang Cheng, Dong Xu
Purpose The purpose of this paper on the one hand is to reduce the sintering temperature, shorten the sintering time and improve the electrical properties of the sample through the two-step flash sintering method and on the other hand is to study the effect of electric field on the phase structure, microstructure and electrical properties of the flash sintering sample. Design/methodology/approach In this paper, (Mg1/3Ta2/3)0.01Ti0.99O2 giant dielectric ceramics were prepared by conventional sintering and two-step flash sintering, respectively. Further, the effect of electric field (600–750 V/cm) on the electrical properties of (Mg1/3Ta2/3)0.01Ti0.99O2 giant dielectric ceramics was studied. Findings The results show that compared with the conventional sintering, the sintering temperature of the two-step flash sintering can be reduced by 200°C and the sintering time can be shortened by 12 times. All sintered samples were single rutile TiO2 structure. Compared with conventional sintering, two-step flash sintering samples have finer grain size. The two-step flash sintered sample has similar dielectric properties to the conventional sintered sample. The dielectric constant of flash sintered samples decreases with the increase of electric field. When the electric field is 700 V/cm, the ceramic sample has the optimal dielectric properties, where the dielectric constant is approximately 5.5 × 103 and the dielectric loss is about 0.18 at 1 kHz. Impedance spectroscopy analysis shows that the excellent dielectric properties are attributed to the internal barrier layer capacitance model. Originality/value This paper not only provides a new method for the preparation of co-doped TiO2 giant dielectric ceramics but also has great potential in greatly improving efficiency and saving energy.
{"title":"Two-step flash sintering of (Mg1/3Ta2/3)0.01Ti0.99O2 giant dielectric ceramics","authors":"Zhentao Wang, Pai Peng, Sujuan Zhong, Yafang Cheng, Dong Xu","doi":"10.1108/mi-06-2022-0116","DOIUrl":"https://doi.org/10.1108/mi-06-2022-0116","url":null,"abstract":"\u0000Purpose\u0000The purpose of this paper on the one hand is to reduce the sintering temperature, shorten the sintering time and improve the electrical properties of the sample through the two-step flash sintering method and on the other hand is to study the effect of electric field on the phase structure, microstructure and electrical properties of the flash sintering sample.\u0000\u0000\u0000Design/methodology/approach\u0000In this paper, (Mg1/3Ta2/3)0.01Ti0.99O2 giant dielectric ceramics were prepared by conventional sintering and two-step flash sintering, respectively. Further, the effect of electric field (600–750 V/cm) on the electrical properties of (Mg1/3Ta2/3)0.01Ti0.99O2 giant dielectric ceramics was studied.\u0000\u0000\u0000Findings\u0000The results show that compared with the conventional sintering, the sintering temperature of the two-step flash sintering can be reduced by 200°C and the sintering time can be shortened by 12 times. All sintered samples were single rutile TiO2 structure. Compared with conventional sintering, two-step flash sintering samples have finer grain size. The two-step flash sintered sample has similar dielectric properties to the conventional sintered sample. The dielectric constant of flash sintered samples decreases with the increase of electric field. When the electric field is 700 V/cm, the ceramic sample has the optimal dielectric properties, where the dielectric constant is approximately 5.5 × 103 and the dielectric loss is about 0.18 at 1 kHz. Impedance spectroscopy analysis shows that the excellent dielectric properties are attributed to the internal barrier layer capacitance model.\u0000\u0000\u0000Originality/value\u0000This paper not only provides a new method for the preparation of co-doped TiO2 giant dielectric ceramics but also has great potential in greatly improving efficiency and saving energy.\u0000","PeriodicalId":49817,"journal":{"name":"Microelectronics International","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43792410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nuha A. Rhaffor, Wei Keat Ang, Mohamed Fauzi Packeer Mohamed, J. Rajendran, N. Mohd Noh, M. T. Mustaffa, M. Hairi
Purpose The purpose of this study is to show that due to the emergence of the Internet of Things (IoT) industry in recent years, the demand for the higher integration of wireless communication systems with a higher data rate of transmission capacity and lower power consumption has increased tremendously. The radio frequency power amplifier (PA) design is getting more challenging and crucial. A PA for a 2.45 GHz IoT application using 0.18 µm complementary metal oxide semiconductor (CMOS) technology is presented in this paper. Design/methodology/approach The design consists of two stages, the driver and output stage, where both use a single-stage common source transistor configuration. In view of performance, the PA can deliver more than 20 dB gain from 2.4 GHz to 2.5 GHz. Findings The maximum output power achieved by PA is 13.28 dBm. As the PA design is targeted for Bluetooth low energy (BLE) transmitter use, a minimum of 10 dBm output power should be achieved by PA to transmit the signal in BLE standard. The PA exhibits a constant output third-order interception point of 18 dBm before PA becomes saturated after 10 dBm output power. The PA shows a peak power added efficiency of 17.82% at the 13.24 dBm output power. Originality/value The PA design exhibits good linearity up to 10 dBm out the PA design exhibits good linearity up to 10 dBm output power without sacrificing efficiency. At the operating frequency of 2.45 GHz, the PA exhibits a stability k-factor, the value of more than 1; thus, the PA design is considered unconditional stable. Besides, the PA shows the s-parameters performance of –7.91 dB for S11, –11.07 dB for S22 and 21.5 dB for S21.
{"title":"Design of radio frequency power amplifier for 2.45 GHz IoT application using 0.18 µm CMOS technology","authors":"Nuha A. Rhaffor, Wei Keat Ang, Mohamed Fauzi Packeer Mohamed, J. Rajendran, N. Mohd Noh, M. T. Mustaffa, M. Hairi","doi":"10.1108/mi-03-2022-0040","DOIUrl":"https://doi.org/10.1108/mi-03-2022-0040","url":null,"abstract":"\u0000Purpose\u0000The purpose of this study is to show that due to the emergence of the Internet of Things (IoT) industry in recent years, the demand for the higher integration of wireless communication systems with a higher data rate of transmission capacity and lower power consumption has increased tremendously. The radio frequency power amplifier (PA) design is getting more challenging and crucial. A PA for a 2.45 GHz IoT application using 0.18 µm complementary metal oxide semiconductor (CMOS) technology is presented in this paper.\u0000\u0000\u0000Design/methodology/approach\u0000The design consists of two stages, the driver and output stage, where both use a single-stage common source transistor configuration. In view of performance, the PA can deliver more than 20 dB gain from 2.4 GHz to 2.5 GHz.\u0000\u0000\u0000Findings\u0000The maximum output power achieved by PA is 13.28 dBm. As the PA design is targeted for Bluetooth low energy (BLE) transmitter use, a minimum of 10 dBm output power should be achieved by PA to transmit the signal in BLE standard. The PA exhibits a constant output third-order interception point of 18 dBm before PA becomes saturated after 10 dBm output power. The PA shows a peak power added efficiency of 17.82% at the 13.24 dBm output power.\u0000\u0000\u0000Originality/value\u0000The PA design exhibits good linearity up to 10 dBm out the PA design exhibits good linearity up to 10 dBm output power without sacrificing efficiency. At the operating frequency of 2.45 GHz, the PA exhibits a stability k-factor, the value of more than 1; thus, the PA design is considered unconditional stable. Besides, the PA shows the s-parameters performance of –7.91 dB for S11, –11.07 dB for S22 and 21.5 dB for S21.\u0000","PeriodicalId":49817,"journal":{"name":"Microelectronics International","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45209002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Purpose The purpose of this paper is to develop and test the thermal interface materials (TIM) for application in assembly of semiconductor chips to package. Good adhesion properties (>5 MPa shear strength) and low thermal interface resistance (better than for SAC solders) are the goal of this research. Design/methodology/approach Mechanical and thermal properties of TIM joints between gold plated contacts of chip and substrate were investigated. Sintering technique based on Ag pastes was applied for purpose of this study. Performance properties were assessed by shear force tests and thermal measurements. Scanning electron microscopy was used for microstructural observations of cross-section of formed joints. Findings It was concluded that the best properties are achieved for pastes containing spherical Ag particles of dozens of micrometer size with flake shaped Ag particles of few micrometers size. Sintering temperature at 230°C and application of 1 MPa force on the chip during sintering gave the higher adhesion and the lowest thermal interface resistance. Originality/value The new material based on Ag paste containing mixtures of Ag particles of different size (form nanometer to dozens of microns) and shape (spherical, flake) suspended in resin was proposed. Joints prepared using sintering technique and Ag pastes at 230°C with applied pressure shows better mechanical and thermal than other TIM materials such as thermal grease, thermal gel or thermally conductive adhesive. Those material could enable electronic device operation at temperatures above 200°C, currently unavailable for Si-based power electronics.
{"title":"Influence of Ag particle shape on mechanical and thermal properties of TIM joints","authors":"M. Myśliwiec, R. Kisiel, M. Kruszewski","doi":"10.1108/mi-06-2022-0108","DOIUrl":"https://doi.org/10.1108/mi-06-2022-0108","url":null,"abstract":"\u0000Purpose\u0000The purpose of this paper is to develop and test the thermal interface materials (TIM) for application in assembly of semiconductor chips to package. Good adhesion properties (>5 MPa shear strength) and low thermal interface resistance (better than for SAC solders) are the goal of this research.\u0000\u0000\u0000Design/methodology/approach\u0000Mechanical and thermal properties of TIM joints between gold plated contacts of chip and substrate were investigated. Sintering technique based on Ag pastes was applied for purpose of this study. Performance properties were assessed by shear force tests and thermal measurements. Scanning electron microscopy was used for microstructural observations of cross-section of formed joints.\u0000\u0000\u0000Findings\u0000It was concluded that the best properties are achieved for pastes containing spherical Ag particles of dozens of micrometer size with flake shaped Ag particles of few micrometers size. Sintering temperature at 230°C and application of 1 MPa force on the chip during sintering gave the higher adhesion and the lowest thermal interface resistance.\u0000\u0000\u0000Originality/value\u0000The new material based on Ag paste containing mixtures of Ag particles of different size (form nanometer to dozens of microns) and shape (spherical, flake) suspended in resin was proposed. Joints prepared using sintering technique and Ag pastes at 230°C with applied pressure shows better mechanical and thermal than other TIM materials such as thermal grease, thermal gel or thermally conductive adhesive. Those material could enable electronic device operation at temperatures above 200°C, currently unavailable for Si-based power electronics.\u0000","PeriodicalId":49817,"journal":{"name":"Microelectronics International","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47577962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mazwan Mansor, Syamsul M., Y. Yusuf, Mohd Nazri Abdul Rahman
Purpose This study aims to present a numerical study of atomic structure for aluminium nitride (AlN) when the crystal was assumed grown on different orientation of sapphire substrate. The change of the AlN atomic structure with sapphire orientation was associated to the interface between the AlN and the sapphire. The results from this study would provide a guideline in selecting suitable orientation of sapphire for obtaining desirable AlN crystals, in particular, for reducing threading dislocation density in the AlN/sapphire templates for developing UV LEDs. Design/methodology/approach The approach of atomic structure by visualization for electronic and structural analysis numerical method to develop shape of atomic geometry to evaluate which plane are more suitable for the AlGaN technology UV-LED based. Findings The calculation based on ratio on first and second layers can be done by introduction of lattice constant. Research limitations/implications With plane’s color of cutting plane on bulky materials, all the shape looks the same. Practical implications By implementing this method, the authors can save time to find the most suitable plane on the growth structure. Originality/value All authors of this research paper have directly participated in the planning, execution or analysis of the study; all authors of this paper have read and approved the final version submitted; the contents of this manuscript have not been copyrighted or published previously; the contents of this manuscript are not now under consideration for publication elsewhere; the contents of this manuscript will not be copyrighted, submitted or published elsewhere, whereas acceptance by the journal is under consideration.
{"title":"Atomic structure for AlN grown on different plane orientation of sapphire via numerical study","authors":"Mazwan Mansor, Syamsul M., Y. Yusuf, Mohd Nazri Abdul Rahman","doi":"10.1108/mi-04-2022-0065","DOIUrl":"https://doi.org/10.1108/mi-04-2022-0065","url":null,"abstract":"\u0000Purpose\u0000This study aims to present a numerical study of atomic structure for aluminium nitride (AlN) when the crystal was assumed grown on different orientation of sapphire substrate. The change of the AlN atomic structure with sapphire orientation was associated to the interface between the AlN and the sapphire. The results from this study would provide a guideline in selecting suitable orientation of sapphire for obtaining desirable AlN crystals, in particular, for reducing threading dislocation density in the AlN/sapphire templates for developing UV LEDs.\u0000\u0000\u0000Design/methodology/approach\u0000The approach of atomic structure by visualization for electronic and structural analysis numerical method to develop shape of atomic geometry to evaluate which plane are more suitable for the AlGaN technology UV-LED based.\u0000\u0000\u0000Findings\u0000The calculation based on ratio on first and second layers can be done by introduction of lattice constant.\u0000\u0000\u0000Research limitations/implications\u0000With plane’s color of cutting plane on bulky materials, all the shape looks the same.\u0000\u0000\u0000Practical implications\u0000By implementing this method, the authors can save time to find the most suitable plane on the growth structure.\u0000\u0000\u0000Originality/value\u0000All authors of this research paper have directly participated in the planning, execution or analysis of the study; all authors of this paper have read and approved the final version submitted; the contents of this manuscript have not been copyrighted or published previously; the contents of this manuscript are not now under consideration for publication elsewhere; the contents of this manuscript will not be copyrighted, submitted or published elsewhere, whereas acceptance by the journal is under consideration.\u0000","PeriodicalId":49817,"journal":{"name":"Microelectronics International","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46511365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Naeem Islam, Nur Syahadah Yusof, Mohamed Fauzi Packeer Mohamed, Syamsul M., Muhammad Firdaus Akbar Jalaludin Khan, N. Ghazali, M. Hairi
Purpose The purpose of this study is to demonstrate a pseudomorphic High Electron Mobility Transistor (pHEMT) cutoff frequency (fT) and maximum oscillation frequency (fmax) are determined by the role of its gate length (Lg). Theoretically, to obtain an Lg of 1 µm, the gate’s resist opening must be 1 µm wide. However, after the coat-expose-develop (C-E-D) process, the Lg became 13% larger after metal evaporation. This enlargement is due to both resist thickness and its profile. Design/methodology/approach This research aims to optimize the 1-µm Lg InGaAs-InAlAs pHEMT C-E-D process, where the diluted AZ®nLOF™ 2070 resist with AZ® EBR solvent technique has been used to solve the Lg enlargement problem. The dilution theoretically allows the changing of a resist thickness to different film thickness using the same coating parameters. Here, for getting a new resist, which is simply called AZ 0.5 µm, the experiment’s important parameters such as the coater’s spin speed of 3,000 rpm and soft bake at 110°C for 5 min are executed. Findings The newly mixed AZ 0.5 µm resist has presented a high resolution and undercut profile rather than standard AZ 1 µm resist. Hence, the Lg metallization after using AZ 0.5 µm optimized process showed better results than AZ 1 µm which used the standard process. Originality/value The outcome of the optimization has reached that it is possible to get a nearly sub-µm range gate’s opening using a diluted resist, and at the same time retaining a high resolution and undercut profile.
本研究的目的是证明伪晶高电子迁移率晶体管(pHEMT)的截止频率(fT)和最大振荡频率(fmax)是由其栅极长度(Lg)的作用决定的。理论上，为了获得1 μ m的Lg，栅极的电阻开口必须为1 μ m宽。然而，经过涂层曝光显影(C-E-D)工艺后，金属蒸发后Lg增大了13%。这种增大是由于抗蚀剂的厚度和它的轮廓。本研究旨在优化1 μ m Lg InGaAs-InAlAs pHEMT C-E-D工艺，其中使用稀释的AZ®nLOF™2070抗蚀剂与AZ®EBR溶剂技术来解决Lg放大问题。稀释理论上允许使用相同的涂层参数改变抗蚀剂厚度到不同的薄膜厚度。在这里，为了获得新的抗蚀剂，简称az0.5µm，实验的重要参数，如涂布机的旋转速度为3,000 rpm和在110°C下软烘烤5分钟。新混合的az0.5µm抗蚀剂具有高分辨率和凹边轮廓，而不是标准的az1µm抗蚀剂。因此，采用az0.5µm优化工艺后的Lg金属化效果优于采用az1µm标准工艺的Lg金属化效果。原创性/价值优化的结果已经达到，可以使用稀释的抗蚀剂获得近亚微米范围的栅极开口，同时保持高分辨率和凹边轮廓。
{"title":"Optimization of 1-µm gate length InGaAs-InAlAs pHEMT","authors":"Naeem Islam, Nur Syahadah Yusof, Mohamed Fauzi Packeer Mohamed, Syamsul M., Muhammad Firdaus Akbar Jalaludin Khan, N. Ghazali, M. Hairi","doi":"10.1108/mi-03-2022-0044","DOIUrl":"https://doi.org/10.1108/mi-03-2022-0044","url":null,"abstract":"\u0000Purpose\u0000The purpose of this study is to demonstrate a pseudomorphic High Electron Mobility Transistor (pHEMT) cutoff frequency (fT) and maximum oscillation frequency (fmax) are determined by the role of its gate length (Lg). Theoretically, to obtain an Lg of 1 µm, the gate’s resist opening must be 1 µm wide. However, after the coat-expose-develop (C-E-D) process, the Lg became 13% larger after metal evaporation. This enlargement is due to both resist thickness and its profile.\u0000\u0000\u0000Design/methodology/approach\u0000This research aims to optimize the 1-µm Lg InGaAs-InAlAs pHEMT C-E-D process, where the diluted AZ®nLOF™ 2070 resist with AZ® EBR solvent technique has been used to solve the Lg enlargement problem. The dilution theoretically allows the changing of a resist thickness to different film thickness using the same coating parameters. Here, for getting a new resist, which is simply called AZ 0.5 µm, the experiment’s important parameters such as the coater’s spin speed of 3,000 rpm and soft bake at 110°C for 5 min are executed.\u0000\u0000\u0000Findings\u0000The newly mixed AZ 0.5 µm resist has presented a high resolution and undercut profile rather than standard AZ 1 µm resist. Hence, the Lg metallization after using AZ 0.5 µm optimized process showed better results than AZ 1 µm which used the standard process.\u0000\u0000\u0000Originality/value\u0000The outcome of the optimization has reached that it is possible to get a nearly sub-µm range gate’s opening using a diluted resist, and at the same time retaining a high resolution and undercut profile.\u0000","PeriodicalId":49817,"journal":{"name":"Microelectronics International","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46637804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Wang, Chenhui Xia, Bo Wang, Xinran Zhao, Yang Li, Ning Yang
Purpose A W-band antennas-in-packages (AIP) module with a hybrid stacked glass-compound wafer level fan-out process was presented. Heterogeneous radio frequency (RF) chips were integrated into one single module with a microscale fan-out process. This paper aims to find a new strategy for 5G communication with 3D integration of multi-function chips. Design/methodology/approach The AIP module was composed of two stacked layers: the antenna layer and RF layer. After architecture design and performance simulation, the module was fabricated, The 8 × 8 antenna array was lithography patterned on the 12 inch glass wafer to reduce the parasitic parameters effect, and the signal feeding interface was fabricated on the backside of the glass substrate. Findings AIP module demonstrates a size of 180 mm × 180mm × 1mm, and its function covers the complete RF front-end chain from the antenna to signal to process and can be applied in 5 G communication and automotive components. Originality/value With three RF multi-function chips and two through silicon via (TSV) chips were embedded in the 12 inch compound wafer through the fan-out packaging process; two layers were interconnected with TSV and re-distributed layers.
{"title":"W-band antenna in package module with hybrid glass-compound WLFO process","authors":"G. Wang, Chenhui Xia, Bo Wang, Xinran Zhao, Yang Li, Ning Yang","doi":"10.1108/mi-06-2022-0111","DOIUrl":"https://doi.org/10.1108/mi-06-2022-0111","url":null,"abstract":"Purpose A W-band antennas-in-packages (AIP) module with a hybrid stacked glass-compound wafer level fan-out process was presented. Heterogeneous radio frequency (RF) chips were integrated into one single module with a microscale fan-out process. This paper aims to find a new strategy for 5G communication with 3D integration of multi-function chips. Design/methodology/approach The AIP module was composed of two stacked layers: the antenna layer and RF layer. After architecture design and performance simulation, the module was fabricated, The 8 × 8 antenna array was lithography patterned on the 12 inch glass wafer to reduce the parasitic parameters effect, and the signal feeding interface was fabricated on the backside of the glass substrate. Findings AIP module demonstrates a size of 180 mm × 180mm × 1mm, and its function covers the complete RF front-end chain from the antenna to signal to process and can be applied in 5 G communication and automotive components. Originality/value With three RF multi-function chips and two through silicon via (TSV) chips were embedded in the 12 inch compound wafer through the fan-out packaging process; two layers were interconnected with TSV and re-distributed layers.","PeriodicalId":49817,"journal":{"name":"Microelectronics International","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43478350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Youxin Zhang, Yang Liu, Rongxing Cao, Xianghua Zeng, Yuxiong Xue
Purpose Concerning the radiation effects on the three-dimensional (3D) packaging in space environment, this study aims to investigate the influence of the total dose effect on the transmission characteristics of high-frequency electrical signals using experimental and simulation methods. Design/methodology/approach This work carries out the irradiation test of the specimens and measures their S21 parameters before and after irradiation. A simulation model describing the total dose effect was built based on the experimental test results. And, the radiation hardening design is evaluated by the simulation method. Findings The experimental results demonstrate that the S21 curve of the interconnection decreases with the increase of the irradiation dose, indicating that the total dose effect leads to the decline of its signal transmission characteristics. According to the simulation results, decreasing the height of the through silicon via (TSV), increasing the radius of the TSV, reducing the length of Si and increasing the number of grounded through silicon via have positive effects on improving the radiation resistance of the interconnection structure. Originality/value This work investigates the effect of radiation on the transmission characteristics of interconnection structures for 3D packaging and proposes the hardening design methods. It is meaningful for improving the reliability of 3D packaging in space applications.
{"title":"Effects of 60Co γ ray radiation on the transmission characteristics of interconnection structures for 3D packaging","authors":"Youxin Zhang, Yang Liu, Rongxing Cao, Xianghua Zeng, Yuxiong Xue","doi":"10.1108/mi-07-2022-0120","DOIUrl":"https://doi.org/10.1108/mi-07-2022-0120","url":null,"abstract":"\u0000Purpose\u0000Concerning the radiation effects on the three-dimensional (3D) packaging in space environment, this study aims to investigate the influence of the total dose effect on the transmission characteristics of high-frequency electrical signals using experimental and simulation methods.\u0000\u0000\u0000Design/methodology/approach\u0000This work carries out the irradiation test of the specimens and measures their S21 parameters before and after irradiation. A simulation model describing the total dose effect was built based on the experimental test results. And, the radiation hardening design is evaluated by the simulation method.\u0000\u0000\u0000Findings\u0000The experimental results demonstrate that the S21 curve of the interconnection decreases with the increase of the irradiation dose, indicating that the total dose effect leads to the decline of its signal transmission characteristics. According to the simulation results, decreasing the height of the through silicon via (TSV), increasing the radius of the TSV, reducing the length of Si and increasing the number of grounded through silicon via have positive effects on improving the radiation resistance of the interconnection structure.\u0000\u0000\u0000Originality/value\u0000This work investigates the effect of radiation on the transmission characteristics of interconnection structures for 3D packaging and proposes the hardening design methods. It is meaningful for improving the reliability of 3D packaging in space applications.\u0000","PeriodicalId":49817,"journal":{"name":"Microelectronics International","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45878543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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