Pub Date : 2014-12-29DOI: 10.1109/ASDAM.2014.6998677
M. Florovič, J. Kovác, P. Benko, J. Škriniarová, P. Kordos, D. Donoval
This paper reports on degradation processes in the AlGaN/GaN HEMTs under high drain-bias off-state stress. The devices were off-stressed at the drain voltage of 60 V and the gate voltage of -5 V for 30 min, resp.60 min. Static device performance was evaluated before, during and after the stress. Performed measurements show a slight degradation in the drain current and a decrease of the threshold voltage. However, these effects are partially recovered as follows from the measurement performed 30 min after the stress. All these indicates that the electrons that accumulate in the structure as well as on the surface of AlGaN layer create an electrostatic charge induced by high electric field between gate and drain. This causes a reduction in the channel current and plays a major role during the off-state degradation of AlGaN/GaN HEMTs.
{"title":"Degradation processes in AlGaN/GaN HEMTs under high drain-bias off-state stress","authors":"M. Florovič, J. Kovác, P. Benko, J. Škriniarová, P. Kordos, D. Donoval","doi":"10.1109/ASDAM.2014.6998677","DOIUrl":"https://doi.org/10.1109/ASDAM.2014.6998677","url":null,"abstract":"This paper reports on degradation processes in the AlGaN/GaN HEMTs under high drain-bias off-state stress. The devices were off-stressed at the drain voltage of 60 V and the gate voltage of -5 V for 30 min, resp.60 min. Static device performance was evaluated before, during and after the stress. Performed measurements show a slight degradation in the drain current and a decrease of the threshold voltage. However, these effects are partially recovered as follows from the measurement performed 30 min after the stress. All these indicates that the electrons that accumulate in the structure as well as on the surface of AlGaN layer create an electrostatic charge induced by high electric field between gate and drain. This causes a reduction in the channel current and plays a major role during the off-state degradation of AlGaN/GaN HEMTs.","PeriodicalId":313866,"journal":{"name":"The Tenth International Conference on Advanced Semiconductor Devices and Microsystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124723060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-12-29DOI: 10.1109/ASDAM.2014.6998641
A. Kosa, J. Benkovska, L. Stuchlíková, D. Búc, F. Dubecký, L. Harmatha
Deep level transient spectroscopy is utilized to investigate radiation induced defects in three types of 4H-SiC Schottky diode structures by combined neutron and gamma bombardment and fast electron irradiation. Main attention is devoted to the comparison of observed spectra by non irradiated and irradiated structures in order to evaluate the radiation hardness of these structures. As a significant deep energy level the Z1/Z2 centre present in all structures is reported.
{"title":"Radiation hardness of 4H-SiC structuresues","authors":"A. Kosa, J. Benkovska, L. Stuchlíková, D. Búc, F. Dubecký, L. Harmatha","doi":"10.1109/ASDAM.2014.6998641","DOIUrl":"https://doi.org/10.1109/ASDAM.2014.6998641","url":null,"abstract":"Deep level transient spectroscopy is utilized to investigate radiation induced defects in three types of 4H-SiC Schottky diode structures by combined neutron and gamma bombardment and fast electron irradiation. Main attention is devoted to the comparison of observed spectra by non irradiated and irradiated structures in order to evaluate the radiation hardness of these structures. As a significant deep energy level the Z1/Z2 centre present in all structures is reported.","PeriodicalId":313866,"journal":{"name":"The Tenth International Conference on Advanced Semiconductor Devices and Microsystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124891412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-12-29DOI: 10.1109/ASDAM.2014.6998666
A. Šatka, J. Priesol, M. Bernat, D. Donoval, J. Kovác, D. Allsopp, J. Kuzmík
Transient phenomena in depletion-mode Gallium Nitride (GaN) Heterostructure Field-Effect Transistor (HFET) structures biased to various operation points corresponding to their real applications has been studied using Time-Resolved Electron Beam Induced Current (TREBIC) method. It has been found, that the amplitude and shape of the transient response depends on the gate voltage VGs and position of the electron beam in the active region of the HFET. Inhomogeneous lateral build-up and recovery of electric field has been observed at the gate in the drain access region of the HFETs, attributed to inhomogeneous distribution of the trapping centres in proximity of the Schottky gate electrode.
{"title":"Time resolved EBIC study of InAlN/GaN HFETs","authors":"A. Šatka, J. Priesol, M. Bernat, D. Donoval, J. Kovác, D. Allsopp, J. Kuzmík","doi":"10.1109/ASDAM.2014.6998666","DOIUrl":"https://doi.org/10.1109/ASDAM.2014.6998666","url":null,"abstract":"Transient phenomena in depletion-mode Gallium Nitride (GaN) Heterostructure Field-Effect Transistor (HFET) structures biased to various operation points corresponding to their real applications has been studied using Time-Resolved Electron Beam Induced Current (TREBIC) method. It has been found, that the amplitude and shape of the transient response depends on the gate voltage VGs and position of the electron beam in the active region of the HFET. Inhomogeneous lateral build-up and recovery of electric field has been observed at the gate in the drain access region of the HFETs, attributed to inhomogeneous distribution of the trapping centres in proximity of the Schottky gate electrode.","PeriodicalId":313866,"journal":{"name":"The Tenth International Conference on Advanced Semiconductor Devices and Microsystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123529428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-12-29DOI: 10.1109/ASDAM.2014.6998645
K. Indykiewicz, B. Paszkiewicz, T. Szymański, R. Paszkiewicz
In the paper simple estimation method of development influence on final structures resolution in resist stack is proposed. The importance of analysis of development process in electron beam lithography is shown. Presented issues are enhancements of Monte Carlo simulations of e-beam influence on resists and as coupled calculations should be used in lithography process design. Performed analysis found good confirmations with conducted experiments.
{"title":"Development issue in mushroom-like profile fabrication in EBL double step exposure method","authors":"K. Indykiewicz, B. Paszkiewicz, T. Szymański, R. Paszkiewicz","doi":"10.1109/ASDAM.2014.6998645","DOIUrl":"https://doi.org/10.1109/ASDAM.2014.6998645","url":null,"abstract":"In the paper simple estimation method of development influence on final structures resolution in resist stack is proposed. The importance of analysis of development process in electron beam lithography is shown. Presented issues are enhancements of Monte Carlo simulations of e-beam influence on resists and as coupled calculations should be used in lithography process design. Performed analysis found good confirmations with conducted experiments.","PeriodicalId":313866,"journal":{"name":"The Tenth International Conference on Advanced Semiconductor Devices and Microsystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128141021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-12-29DOI: 10.1109/ASDAM.2014.6998696
K. Cico, A. Adikimenakis, M. Mičušík, S. Hascik, A. Georgakilas, J. Kuzmík
Angle-resolved XPS-analysis of the bare InN surface has revealed surface electron accumulation and negative band bending by about 0.65 eV at a distance of 1.1 nm. On the other hand this effect was substantially reduced by capping the InN surface by 2 to 4 monolayer of GaN. Negative polarisation charge at the GaN/InN interface of (partially) strained cap layer together with elimination of dangling bonds at the InN surface were consequently suggested. RIE in CCl2F2 provided highly selective etching of GaN over InN. Al2O3 deposited by ALD on (GaN)/InN surface created structures with metal-insulator-metal-like behaviour.
{"title":"Material and electrical properties of N-polar (GaN)/InN surfaces","authors":"K. Cico, A. Adikimenakis, M. Mičušík, S. Hascik, A. Georgakilas, J. Kuzmík","doi":"10.1109/ASDAM.2014.6998696","DOIUrl":"https://doi.org/10.1109/ASDAM.2014.6998696","url":null,"abstract":"Angle-resolved XPS-analysis of the bare InN surface has revealed surface electron accumulation and negative band bending by about 0.65 eV at a distance of 1.1 nm. On the other hand this effect was substantially reduced by capping the InN surface by 2 to 4 monolayer of GaN. Negative polarisation charge at the GaN/InN interface of (partially) strained cap layer together with elimination of dangling bonds at the InN surface were consequently suggested. RIE in CCl2F2 provided highly selective etching of GaN over InN. Al2O3 deposited by ALD on (GaN)/InN surface created structures with metal-insulator-metal-like behaviour.","PeriodicalId":313866,"journal":{"name":"The Tenth International Conference on Advanced Semiconductor Devices and Microsystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128978056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-12-29DOI: 10.1109/ASDAM.2014.6998664
R. Stoklas, D. Gregušová, M. Blaho, K. Cico, K. Frohlich, J. Novák, P. Kordos
The gate leakage reduction about four to seven orders of magnitude for HfO2 MOSHFETs (~10-10A/mm at -15V) prepared by Atomic Layer Deposition (ALD) technique at 350°C with and without oxygen-plasma treatment in comparison to HFET, was observed. A lower hysteresis evaluated from c-V curves of MOSHFET with oxygen-plasma treatment (OPT) after annealing (500°C for 15 min in N2) was found. The C-V curve for MOSHFET without OPT exhibited an increase of capacitance at negative voltages which corresponds with hypothesis of the interfacial layer formation at the oxide/GaN interface. And also, the high density of oxide interface states affects adversely the interface quality, like as the C-V hysteresis, leakage current, hot electron phenomena, etc.
{"title":"Gate leakage reduction of AlGaN/GaN MOS-HFETs with HfO2 prepared by ALD","authors":"R. Stoklas, D. Gregušová, M. Blaho, K. Cico, K. Frohlich, J. Novák, P. Kordos","doi":"10.1109/ASDAM.2014.6998664","DOIUrl":"https://doi.org/10.1109/ASDAM.2014.6998664","url":null,"abstract":"The gate leakage reduction about four to seven orders of magnitude for HfO2 MOSHFETs (~10-10A/mm at -15V) prepared by Atomic Layer Deposition (ALD) technique at 350°C with and without oxygen-plasma treatment in comparison to HFET, was observed. A lower hysteresis evaluated from c-V curves of MOSHFET with oxygen-plasma treatment (OPT) after annealing (500°C for 15 min in N2) was found. The C-V curve for MOSHFET without OPT exhibited an increase of capacitance at negative voltages which corresponds with hypothesis of the interfacial layer formation at the oxide/GaN interface. And also, the high density of oxide interface states affects adversely the interface quality, like as the C-V hysteresis, leakage current, hot electron phenomena, etc.","PeriodicalId":313866,"journal":{"name":"The Tenth International Conference on Advanced Semiconductor Devices and Microsystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125671262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-12-29DOI: 10.1109/ASDAM.2014.6998634
M. D. Dankoco, E. Benevent, E. Bergeret, L. Gallais, M. Bendahan
This paper presents fabrication and characterization of flexible temperature sensor patterned by laser ablation. This work covers the preliminary study on the resistive temperature devices (RTDs) reference sensors used to measure the temperature of human body for health applications. The sensors are composed of different materials like platinum (Pt), copper (Cu) and silver (Ag) as sensitive materials. These different sensitive materials have been deposed on flexible substrate (Kapton®) by radiofrequency (RF) magnetron sputtering process and patterned by laser ablation using a femtosecond laser. The performance of the temperature sensors is evaluated and compared.
{"title":"Temperature sensor on flexible substrate patterned by laser ablation","authors":"M. D. Dankoco, E. Benevent, E. Bergeret, L. Gallais, M. Bendahan","doi":"10.1109/ASDAM.2014.6998634","DOIUrl":"https://doi.org/10.1109/ASDAM.2014.6998634","url":null,"abstract":"This paper presents fabrication and characterization of flexible temperature sensor patterned by laser ablation. This work covers the preliminary study on the resistive temperature devices (RTDs) reference sensors used to measure the temperature of human body for health applications. The sensors are composed of different materials like platinum (Pt), copper (Cu) and silver (Ag) as sensitive materials. These different sensitive materials have been deposed on flexible substrate (Kapton®) by radiofrequency (RF) magnetron sputtering process and patterned by laser ablation using a femtosecond laser. The performance of the temperature sensors is evaluated and compared.","PeriodicalId":313866,"journal":{"name":"The Tenth International Conference on Advanced Semiconductor Devices and Microsystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116981684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-12-29DOI: 10.1109/ASDAM.2014.6998655
M. Novota, M. Micjan, J. Nevrela, S. Flickyngerová, P. Juhasz, R. Mišicák, M. Putala, J. Jakabovic, M. Weis
This work describes the thin-film fabrication technology and characterization of devices based on organic semiconductor 3,6-bis(5`-hexyl-2,2`-bithiophen-5-yl)phenanthrene (H2T36Phen). The surface morphology, optical, and electrical properties are investigated for thin organic films. It demonstrates that the solution-based depositions require different substrate surface treatment than the evaporation-based deposition.
{"title":"New phenanthrene-based organic semiconductor material for electronic devices","authors":"M. Novota, M. Micjan, J. Nevrela, S. Flickyngerová, P. Juhasz, R. Mišicák, M. Putala, J. Jakabovic, M. Weis","doi":"10.1109/ASDAM.2014.6998655","DOIUrl":"https://doi.org/10.1109/ASDAM.2014.6998655","url":null,"abstract":"This work describes the thin-film fabrication technology and characterization of devices based on organic semiconductor 3,6-bis(5`-hexyl-2,2`-bithiophen-5-yl)phenanthrene (H2T36Phen). The surface morphology, optical, and electrical properties are investigated for thin organic films. It demonstrates that the solution-based depositions require different substrate surface treatment than the evaporation-based deposition.","PeriodicalId":313866,"journal":{"name":"The Tenth International Conference on Advanced Semiconductor Devices and Microsystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126596598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-12-29DOI: 10.1109/ASDAM.2014.6998714
P. Pribytny, M. Molnar, A. Chvála, J. Marek, M. Mikolasek, D. Donoval
Numerical modeling and simulation provide an efficient tool for analysis and optimization of device structure design. In this paper we present a method for the design of solar cell. Three methodologies for fully coupled rigorous electro-physical and optical simulation of solar cell are proposed. The first one is based on full 3-D modeling employing TCAD tools applied to a simple solar cell. The second approach, using combined 2-DB-D modeling, is applied to a simple solar cell that reduces the computation time while maintaining a reasonable accuracy. In the third approach we propose a smart coupling between the device and the package that combines the speed and accuracy of mixed mode simulation assuming additional 3-D effects.
{"title":"TCAD simulation methodology for 3-D electro-physical and optical analysis","authors":"P. Pribytny, M. Molnar, A. Chvála, J. Marek, M. Mikolasek, D. Donoval","doi":"10.1109/ASDAM.2014.6998714","DOIUrl":"https://doi.org/10.1109/ASDAM.2014.6998714","url":null,"abstract":"Numerical modeling and simulation provide an efficient tool for analysis and optimization of device structure design. In this paper we present a method for the design of solar cell. Three methodologies for fully coupled rigorous electro-physical and optical simulation of solar cell are proposed. The first one is based on full 3-D modeling employing TCAD tools applied to a simple solar cell. The second approach, using combined 2-DB-D modeling, is applied to a simple solar cell that reduces the computation time while maintaining a reasonable accuracy. In the third approach we propose a smart coupling between the device and the package that combines the speed and accuracy of mixed mode simulation assuming additional 3-D effects.","PeriodicalId":313866,"journal":{"name":"The Tenth International Conference on Advanced Semiconductor Devices and Microsystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115288326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-10-20DOI: 10.1109/ASDAM.2014.6998703
A. Ingenito, O. Isabella, M. Zeman
The need for cost reduction requires using less raw material and cost-effective processes without sacrificing the conversion efficiency. For keeping high the generated photo-current, an advanced light trapping scheme for ultra-thin silicon wafers is here proposed, exhibiting absorptances up to 99% of 4n2 classical absorption limit for wafer thinner than 35 μm. Such excellent optical performance does not reflect optimal electronic properties due to high recombination rate of the nano-textured surface. Therefore, we propose a passivation method involving both wet etching and high quality passivation coating of the nano-textured surface. For wet etching time longer than 30 s recombination rate of the nano-textured surface reduced more than three time with respect to the un-etched one while keeping the averaged reflectance below 2% (between 300 and 1050 nm). Electrical simulations based on such findings indicate that for wafer thinner than 35 μm conversion efficiency higher than 25% can be achieved.
{"title":"Opto-electrical approaches for high efficiency and ultra-thin c-Si solar cells","authors":"A. Ingenito, O. Isabella, M. Zeman","doi":"10.1109/ASDAM.2014.6998703","DOIUrl":"https://doi.org/10.1109/ASDAM.2014.6998703","url":null,"abstract":"The need for cost reduction requires using less raw material and cost-effective processes without sacrificing the conversion efficiency. For keeping high the generated photo-current, an advanced light trapping scheme for ultra-thin silicon wafers is here proposed, exhibiting absorptances up to 99% of 4n2 classical absorption limit for wafer thinner than 35 μm. Such excellent optical performance does not reflect optimal electronic properties due to high recombination rate of the nano-textured surface. Therefore, we propose a passivation method involving both wet etching and high quality passivation coating of the nano-textured surface. For wet etching time longer than 30 s recombination rate of the nano-textured surface reduced more than three time with respect to the un-etched one while keeping the averaged reflectance below 2% (between 300 and 1050 nm). Electrical simulations based on such findings indicate that for wafer thinner than 35 μm conversion efficiency higher than 25% can be achieved.","PeriodicalId":313866,"journal":{"name":"The Tenth International Conference on Advanced Semiconductor Devices and Microsystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125407207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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