In this paper,bulk polarization mechanism and radiation simulation of the Al component gradient buffer layer (GBL) and constant buffer layer (CBL) of p-GaN HEMT (p-GaN GBL-HEMT and p-GaN CBL-HEMT) are analyzed and studied. It is found that the p-GaN GBL-HEMT can significantly reduce the buffer leakage current. The linear gradient amplitude (the range of linear gradients of Al components vertically in the buffer) of 20~30% Al components can significantly increase the breakdown voltage (VBK) of the device, up to 1312V. Simultaneously, although the p-GaN GBL-HEMT reduces the 2DEG concentration, the device still has a specific on-resistance (RON,sp) and drain saturation current (IDS,sat) equivalent to the p-GaN CBL-HEMT due to the conductivity modulation effect. Its Baliga figure of merit is up to 2.27 GW/cm2. Finally, through the SEE simulation and the bulk polarization mechanism analysis, it is found that the drain transient current (IDS,trans) by the identical incident particles in the p-GaN GBL-HEMT is lower than that in the p-GaN CBL-HEMT, and the IDS,trans decreases with the increase of the Al components gradient amplitude. Therefore, the p-GaN GBL-HEMT provides a new idea for improving the electrical performance and SEE hardening.
{"title":"Analysis and simulation of bulk polarization mechanism in p-GaN HEMT with AI component gradient buffer layer","authors":"Shijin Liu, Ying Wang, Xin-Xing Fei, Cheng-hao Yu, Haomin Guo","doi":"10.1088/1361-6641/ad5580","DOIUrl":"https://doi.org/10.1088/1361-6641/ad5580","url":null,"abstract":"\u0000 In this paper,bulk polarization mechanism and radiation simulation of the Al component gradient buffer layer (GBL) and constant buffer layer (CBL) of p-GaN HEMT (p-GaN GBL-HEMT and p-GaN CBL-HEMT) are analyzed and studied. It is found that the p-GaN GBL-HEMT can significantly reduce the buffer leakage current. The linear gradient amplitude (the range of linear gradients of Al components vertically in the buffer) of 20~30% Al components can significantly increase the breakdown voltage (VBK) of the device, up to 1312V. Simultaneously, although the p-GaN GBL-HEMT reduces the 2DEG concentration, the device still has a specific on-resistance (RON,sp) and drain saturation current (IDS,sat) equivalent to the p-GaN CBL-HEMT due to the conductivity modulation effect. Its Baliga figure of merit is up to 2.27 GW/cm2. Finally, through the SEE simulation and the bulk polarization mechanism analysis, it is found that the drain transient current (IDS,trans) by the identical incident particles in the p-GaN GBL-HEMT is lower than that in the p-GaN CBL-HEMT, and the IDS,trans decreases with the increase of the Al components gradient amplitude. Therefore, the p-GaN GBL-HEMT provides a new idea for improving the electrical performance and SEE hardening.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141371797","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}
Pub Date : 2024-06-06DOI: 10.1088/1361-6641/ad54e8
Renfeng Chen, Kaixuan Chen, Junxue Ran, Yijian Song, Xiaodong Qu, Kewei Yang, X. Ji, Junxi Wang, T. Wei
We have presented an effective piezoelectric polarized interface modulation at GaN/Ti Schottky structure and fabricated a flexible GaN-based sensor using double-transfer method. Chemical etching of Ni sacrificial layer is proved to remove the temporary substrate without metal electrodes damages. The fabricated flexible GaN-based sensor with top and bottom Ti metal Schottky contact exhibits current on/off characteristic under external strain, whose current shows a 53.9% reduction by 2.3% tensile strain and a 67.8% enhancement by -2.3% compressive strain at 5V bias voltage. It is found that the light/dark current ratio in the GaN/Ti Schottky junction significantly increases near zero-bias voltage under 2.3% tensile strain, probably indicating the enhanced built-in piezoelectric polarized field at the interface. This work promotes the study of flexible sensor based on wurtzite III-V nitrides for wearable electronics and optoelectronics.
{"title":"Strain-induced polarization modulation at GaN/Ti interface for flexible thin-film sensor","authors":"Renfeng Chen, Kaixuan Chen, Junxue Ran, Yijian Song, Xiaodong Qu, Kewei Yang, X. Ji, Junxi Wang, T. Wei","doi":"10.1088/1361-6641/ad54e8","DOIUrl":"https://doi.org/10.1088/1361-6641/ad54e8","url":null,"abstract":"\u0000 We have presented an effective piezoelectric polarized interface modulation at GaN/Ti Schottky structure and fabricated a flexible GaN-based sensor using double-transfer method. Chemical etching of Ni sacrificial layer is proved to remove the temporary substrate without metal electrodes damages. The fabricated flexible GaN-based sensor with top and bottom Ti metal Schottky contact exhibits current on/off characteristic under external strain, whose current shows a 53.9% reduction by 2.3% tensile strain and a 67.8% enhancement by -2.3% compressive strain at 5V bias voltage. It is found that the light/dark current ratio in the GaN/Ti Schottky junction significantly increases near zero-bias voltage under 2.3% tensile strain, probably indicating the enhanced built-in piezoelectric polarized field at the interface. This work promotes the study of flexible sensor based on wurtzite III-V nitrides for wearable electronics and optoelectronics.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141381528","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}
Pub Date : 2024-06-06DOI: 10.1088/1361-6641/ad54e6
An-Chen Liu, Yu-Wen Huang, H. Chen, Yi-Jun Dong, Po-tsung Tu, Lung-Hsing Hsu, Yung-Yu Lai, Po-Chun Yeh, I-Yu Huang, Hao-chung Kuo
This study investigates the effect of O2 plasma treatment on the physical and electrical properties of the surface region in Schottky-gate AlGaN/GaN high electron mobility transistor (HEMT). We demonstrate that O2 plasma treatment significantly reduces the gate leakage current and enhances the on/off ratio by three orders of magnitude compared to devices without treatment. The O2 plasma treatment removes organic chemical residue and forms Ga-O bonds on the AlGaN surface beneath the gate metal. X-ray photoelectron spectroscopy (XPS) results indicate that the treatment effectively forms a Ga-O compound oxide layer, which provides surface passivation. Furthermore, atomic force microscope (AFM) analysis reveals a 50% reduction in surface roughness after the O2 plasma treatment. Using O2 plasma oxidation treatment caused a shift in the threshold voltage (VTH) of Schottky-gate AlGaN/GaN HEMT. Initially measured at -5.26 V, the VTH value shifted to +0.5 V. Furthermore, we also employ TCAD simulation to assist in the process developed during the manufacturing process. It is worth noting that the drain current decreases as the Ga-O compound oxide layer increases. This is due to effectively depleted the polarization charges at the AlGaN/GaN interfaces during E-mode operation when reducing the thickness of the AlGaN layer beneath the gate metal. Our results demonstrate the importance of O2 plasma surface treatment in achieving optimal device performance. This study systematically discusses the effect of O2 plasma on AlGaN/GaN surface properties and the formation of Ga-O bonding. It offers insights into developing high-performance Schottky-gate AlGaN/GaN HEMT.
{"title":"Investigating the effect of O2 plasma treatment on the operational characteristics of schottky-gate AlGaN/GaN HEMT","authors":"An-Chen Liu, Yu-Wen Huang, H. Chen, Yi-Jun Dong, Po-tsung Tu, Lung-Hsing Hsu, Yung-Yu Lai, Po-Chun Yeh, I-Yu Huang, Hao-chung Kuo","doi":"10.1088/1361-6641/ad54e6","DOIUrl":"https://doi.org/10.1088/1361-6641/ad54e6","url":null,"abstract":"\u0000 This study investigates the effect of O2 plasma treatment on the physical and electrical properties of the surface region in Schottky-gate AlGaN/GaN high electron mobility transistor (HEMT). We demonstrate that O2 plasma treatment significantly reduces the gate leakage current and enhances the on/off ratio by three orders of magnitude compared to devices without treatment. The O2 plasma treatment removes organic chemical residue and forms Ga-O bonds on the AlGaN surface beneath the gate metal. X-ray photoelectron spectroscopy (XPS) results indicate that the treatment effectively forms a Ga-O compound oxide layer, which provides surface passivation. Furthermore, atomic force microscope (AFM) analysis reveals a 50% reduction in surface roughness after the O2 plasma treatment. Using O2 plasma oxidation treatment caused a shift in the threshold voltage (VTH) of Schottky-gate AlGaN/GaN HEMT. Initially measured at -5.26 V, the VTH value shifted to +0.5 V. Furthermore, we also employ TCAD simulation to assist in the process developed during the manufacturing process. It is worth noting that the drain current decreases as the Ga-O compound oxide layer increases. This is due to effectively depleted the polarization charges at the AlGaN/GaN interfaces during E-mode operation when reducing the thickness of the AlGaN layer beneath the gate metal. Our results demonstrate the importance of O2 plasma surface treatment in achieving optimal device performance. This study systematically discusses the effect of O2 plasma on AlGaN/GaN surface properties and the formation of Ga-O bonding. It offers insights into developing high-performance Schottky-gate AlGaN/GaN HEMT.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141376048","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}
Pub Date : 2024-06-06DOI: 10.1088/1361-6641/ad54e9
F. Piva, M. Buffolo, N. Roccato, M. Pilati, Simone Longato, N. Susilo, D. Hauer Vidal, A. Muhin, L. Sulmoni, T. Wernicke, Michael Kneissl, C. de Santi, G. Meneghesso, E. Zanoni, M. Meneghini
We studied four AlGaN-based 265 nm LEDs with increasing QW thickness (1.4 nm, 3 nm, 6 nm, and 9 nm) during a constant current stress at 100 A cm-2. We focused our attention on the parasitic components of the emission spectra at low current levels, and on the optical power recovery observed at high current levels. We associated every parasitic peak or band to a region in the device where they can be generated, also demonstrating if they are related to band-to-band emission or radiative emission through defects. At high current levels, we showed the simultaneous effect of the decrease in injection efficiency in the active region and the increase in non-radiative recombination, by fitting the EQE curves with a mathematical model. Moreover, we associated the optical power recovery with a generation of negative charge near the active region, which led to an increase in injection efficiency in the QW.
{"title":"Investigation of degradation dynamics of 265 nm LEDs assisted by EL measurements and numerical simulations","authors":"F. Piva, M. Buffolo, N. Roccato, M. Pilati, Simone Longato, N. Susilo, D. Hauer Vidal, A. Muhin, L. Sulmoni, T. Wernicke, Michael Kneissl, C. de Santi, G. Meneghesso, E. Zanoni, M. Meneghini","doi":"10.1088/1361-6641/ad54e9","DOIUrl":"https://doi.org/10.1088/1361-6641/ad54e9","url":null,"abstract":"\u0000 We studied four AlGaN-based 265 nm LEDs with increasing QW thickness (1.4 nm, 3 nm, 6 nm, and 9 nm) during a constant current stress at 100 A cm-2. We focused our attention on the parasitic components of the emission spectra at low current levels, and on the optical power recovery observed at high current levels. We associated every parasitic peak or band to a region in the device where they can be generated, also demonstrating if they are related to band-to-band emission or radiative emission through defects. At high current levels, we showed the simultaneous effect of the decrease in injection efficiency in the active region and the increase in non-radiative recombination, by fitting the EQE curves with a mathematical model. Moreover, we associated the optical power recovery with a generation of negative charge near the active region, which led to an increase in injection efficiency in the QW.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141377771","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}
Pub Date : 2024-06-06DOI: 10.1088/1361-6641/ad54e7
Georgios Stefanou, Charles Smith
We calculate how the frequencies of the vibrational modes in a free-standing GaAs bar are changed as a function of the bar’s geometrical features such as length, thickness and shape. After understanding the effect of the physical characteristics we add finger gates that will be used to define quantum dots on the bar and study the system as a function of the length of the suspended finger gates, and their material properties. Finally, we strengthen the bridges in in order that the first vibrational modes occur at a temperature of 100 mK or more, so that all modes can be frozen out when operated in a dilution refrigerator.
{"title":"Calculation and design of GaAs quantum dot devices where the vibrational modes can be frozen out at cryogenic temperatures","authors":"Georgios Stefanou, Charles Smith","doi":"10.1088/1361-6641/ad54e7","DOIUrl":"https://doi.org/10.1088/1361-6641/ad54e7","url":null,"abstract":"\u0000 We calculate how the frequencies of the vibrational modes in a free-standing GaAs bar are changed as a function of the bar’s geometrical features such as length, thickness and shape. After understanding the effect of the physical characteristics we add finger gates that will be used to define quantum dots on the bar and study the system as a function of the length of the suspended finger gates, and their material properties. Finally, we strengthen the bridges in in order that the first vibrational modes occur at a temperature of 100 mK or more, so that all modes can be frozen out when operated in a dilution refrigerator.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141381447","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}
Pub Date : 2024-06-05DOI: 10.1088/1361-6641/ad5466
D. Das, Ujjal Chakraborty, Pranjal Borah
This brief exclusively demonstrates a comprehensive analysis of the adverse impact of interface trap charge (ITC) under the influence of temperature variation on a hetero-stacked (HS) source L-gate tunnel field effect transistor (TFET) having SiGe pocket. An investigation of both static and RF characteristics has been carried out. It appears that ITCs situated at the Silicon (Si)/oxide interface fluctuates the flat-band voltage to alter the various analog/RF parameter characteristics. Uniform ITCs are seen to be less susceptible to degradation in device characteristics. The low frequency noise (LFN) analysis has also been investigated considering the impact of different trap distribution (Uniform and Gaussian) and densities which are compared thereafter. Besides, the temperature dependent LFN has been studied under influence of different distributed ITCs which is rarely explored yet. Moreover, a comparative analysis has been done on the device behaviour and LFN characteristics of HS L-gate TFET structures with and without SiGe pocket. The structure with SiGe pocket is found to be insusceptible to noise effects.
本简介专门展示了在温度变化的影响下，界面陷阱电荷（ITC）对具有硅锗阱的异质堆叠（HS）源 L 栅极隧道场效应晶体管（TFET）的不利影响的综合分析。我们对静态和射频特性进行了研究。结果表明，位于硅（Si）/氧化物界面的 ITC 会波动平带电压，从而改变各种模拟/射频参数特性。均匀的 ITC 不易导致器件特性下降。考虑到不同阱分布（均匀阱和高斯阱）和密度的影响，还对低频噪声（LFN）分析进行了研究，并在之后进行了比较。此外，还研究了在不同分布式 ITC 影响下的随温度变化的低频噪声，这一点目前还很少有人探讨。此外，我们还对带和不带 SiGe 袋的 HS L 栅 TFET 结构的器件行为和 LFN 特性进行了比较分析。结果发现，带 SiGe 袋的结构不易受噪声影响。
{"title":"Interface trap induced RF and low frequency noise analysis under temperature variations of a hetero-stacked source L-gate TFET","authors":"D. Das, Ujjal Chakraborty, Pranjal Borah","doi":"10.1088/1361-6641/ad5466","DOIUrl":"https://doi.org/10.1088/1361-6641/ad5466","url":null,"abstract":"\u0000 This brief exclusively demonstrates a comprehensive analysis of the adverse impact of interface trap charge (ITC) under the influence of temperature variation on a hetero-stacked (HS) source L-gate tunnel field effect transistor (TFET) having SiGe pocket. An investigation of both static and RF characteristics has been carried out. It appears that ITCs situated at the Silicon (Si)/oxide interface fluctuates the flat-band voltage to alter the various analog/RF parameter characteristics. Uniform ITCs are seen to be less susceptible to degradation in device characteristics. The low frequency noise (LFN) analysis has also been investigated considering the impact of different trap distribution (Uniform and Gaussian) and densities which are compared thereafter. Besides, the temperature dependent LFN has been studied under influence of different distributed ITCs which is rarely explored yet. Moreover, a comparative analysis has been done on the device behaviour and LFN characteristics of HS L-gate TFET structures with and without SiGe pocket. The structure with SiGe pocket is found to be insusceptible to noise effects.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141383911","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}
It is generally accepted that there is a trade-off relationship between mobility and stability for oxide thin film transistor (TFT) devices. Different doping ratios of Ln praseodymium (Pr) into indium (In) zinc (Zn) oxide have been employed as the active layer to get 1# and 2# amorphous oxide semiconductor (AOS) TFTs in this work. The 1#-based TFTs exhibited a high mobility of 49.84 cm2 V−1 s−1 due to the increased concentration of In. By further elevating the Pr doping ratio of the film, the 2#-based TFT obtained both a good mobility of 26.65 cm2 V−1 s−1, and a promising stability, showing a positive-bias temperature stress (PBTS) stability of ∆VTH = 1.56 V and a negative-bias temperature illumination stress (NBTIS) stability of ∆VTH = −1.47 V. It was revealed that the low energy charge transfer state of Pr in 2# film absorbs the visible light, leading to suppressed photo-induced carriers and thus a good illumination reliability of the 2#-based TFTs. In practice, the LCD panel based 2# ACT TFT shows a well stable performance even under 10000-nit illumination. The result indicates a promising strategy to accelerate the commercialization of AOS TFTs to large-panel display production.
{"title":"A study on the high mobility and improved reliability of Pr-doped indium zinc oxide thin film transistors","authors":"Juncheng Xiao, Shimin Ge, Zhixiong Jiang, Jing Liu, Dong Yuan, Ce Liang, Miao Xu, Shan Li, Hongyuan Xu, Xianlai Wang, Shengdong Zhang","doi":"10.1088/1361-6641/ad5465","DOIUrl":"https://doi.org/10.1088/1361-6641/ad5465","url":null,"abstract":"\u0000 It is generally accepted that there is a trade-off relationship between mobility and stability for oxide thin film transistor (TFT) devices. Different doping ratios of Ln praseodymium (Pr) into indium (In) zinc (Zn) oxide have been employed as the active layer to get 1# and 2# amorphous oxide semiconductor (AOS) TFTs in this work. The 1#-based TFTs exhibited a high mobility of 49.84 cm2 V−1 s−1 due to the increased concentration of In. By further elevating the Pr doping ratio of the film, the 2#-based TFT obtained both a good mobility of 26.65 cm2 V−1 s−1, and a promising stability, showing a positive-bias temperature stress (PBTS) stability of ∆VTH = 1.56 V and a negative-bias temperature illumination stress (NBTIS) stability of ∆VTH = −1.47 V. It was revealed that the low energy charge transfer state of Pr in 2# film absorbs the visible light, leading to suppressed photo-induced carriers and thus a good illumination reliability of the 2#-based TFTs. In practice, the LCD panel based 2# ACT TFT shows a well stable performance even under 10000-nit illumination. The result indicates a promising strategy to accelerate the commercialization of AOS TFTs to large-panel display production.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141385607","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}
Pub Date : 2024-05-28DOI: 10.1088/1361-6641/ad4d5b
Yazhou Li, Weizhen Yao, Zhanhong Ma, Shaoyan Yang, Xianglin Liu, Chengming Li and Zhanguo Wang
In previous studies, the influence of gas phase and surface reactions on the growth of GaN was mainly calculated through simulations. In this study, a novel gas pre-decomposition device (GPDD) was designed to experimentally investigate the effects of gas phase and surface reactions on GaN growth by changing the length and height of the isolation plates (IPs). By varying the structure of the GPDD, the effects on the growth rate and thickness uniformity of the GaN films were studied. The growth rate of the GaN sample slowed with the extension of the IPs because the longer partition plates led to insufficient gas mixing and premature consumption of the precursor trimethylgallium (TMG). The use of GPDD simultaneously achieves high crystal quality and smooth surface morphology of the GaN film. Owing to the use of GPDD, the decomposition of TMG in the pyrolysis pathway was promoted, which suppressed Ga vacancies and C impurities, resulting in weak yellow luminescence bands in the photoluminescence. This study provides a comprehensive understanding of the chemical reaction mechanism of GaN and plays an important role in promoting the development of metal-organic chemical vapor deposition equipment.
在以往的研究中，气相和表面反应对氮化镓生长的影响主要是通过模拟计算得出的。本研究设计了一种新型气相预分解装置（GPDD），通过改变隔离板（IP）的长度和高度来实验研究气相和表面反应对氮化镓生长的影响。通过改变 GPDD 的结构，研究了对氮化镓薄膜生长速率和厚度均匀性的影响。由于较长的隔离板会导致气体混合不充分和前驱体三甲镓（TMG）的过早消耗，因此 GaN 样品的生长速度随着 IP 的延长而减慢。GPDD 的使用同时实现了 GaN 薄膜的高晶体质量和光滑表面形态。由于使用了 GPDD，促进了 TMG 在热解途径中的分解，从而抑制了 Ga 空位和 C 杂质，导致光致发光中出现微弱的黄色发光带。该研究全面了解了 GaN 的化学反应机理，对推动金属有机化学气相沉积设备的发展具有重要作用。
{"title":"Effect of gas pre-decomposition device on the growth of GaN epitaxial layer","authors":"Yazhou Li, Weizhen Yao, Zhanhong Ma, Shaoyan Yang, Xianglin Liu, Chengming Li and Zhanguo Wang","doi":"10.1088/1361-6641/ad4d5b","DOIUrl":"https://doi.org/10.1088/1361-6641/ad4d5b","url":null,"abstract":"In previous studies, the influence of gas phase and surface reactions on the growth of GaN was mainly calculated through simulations. In this study, a novel gas pre-decomposition device (GPDD) was designed to experimentally investigate the effects of gas phase and surface reactions on GaN growth by changing the length and height of the isolation plates (IPs). By varying the structure of the GPDD, the effects on the growth rate and thickness uniformity of the GaN films were studied. The growth rate of the GaN sample slowed with the extension of the IPs because the longer partition plates led to insufficient gas mixing and premature consumption of the precursor trimethylgallium (TMG). The use of GPDD simultaneously achieves high crystal quality and smooth surface morphology of the GaN film. Owing to the use of GPDD, the decomposition of TMG in the pyrolysis pathway was promoted, which suppressed Ga vacancies and C impurities, resulting in weak yellow luminescence bands in the photoluminescence. This study provides a comprehensive understanding of the chemical reaction mechanism of GaN and plays an important role in promoting the development of metal-organic chemical vapor deposition equipment.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141167497","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}
Pub Date : 2024-05-14DOI: 10.1088/1361-6641/ad4738
Zhi-Yuan Zheng and Ming-Ming Fan
Al doped α-GaOOH nanorod arrays were grown on FTO via hydrothermal processes by using gallium nitrate and aluminum nitrate mixed aqueous solutions with fixed 1:1 mole ratio as precursors. With increasing the gallium nitrate precursor concentrations, the Ga/Al atom ratios in nanorod arrays increase from 0.36 to 2.08, and the length becomes much longer from 650 nm to 1.04 μm. According to the binding energy difference between Ga 2p3/2 core level and its background in x-ray photoelectron spectroscopy, the bandgap is estimated to be around 5.3 ± 0.2 eV. Al doped α-GaOOH nanorod array/FTO photoelectrochemical photodetectors show enhanced self-powered solar-blind UV photodetection properties, with the decrease of Ga precursor concentrations. The maximum responsivity at 255 nm is 0.09 mA W−1, and the fastest response time can reach 0.05 s. The improved photoresponse speed is ascribed from much shorter transportation route, accelerated carrier recombination by recombination centers, and smaller charge transfer resistance at the α-GaOOH/electrolyte interface with decreasing the gallium nitrate precursor concentrations. The stability and responsivity should be further improved. Nevertheless, this work firstly demonstrates the realization of self-powered solar-blind UV photodetection for α-GaOOH nanorod arrays on FTO via Al doping.
{"title":"Fabrication of Al doped α-GaOOH nanorod arrays on FTO for self-powered photoelectrochemical solar-blind UV photodetectors","authors":"Zhi-Yuan Zheng and Ming-Ming Fan","doi":"10.1088/1361-6641/ad4738","DOIUrl":"https://doi.org/10.1088/1361-6641/ad4738","url":null,"abstract":"Al doped α-GaOOH nanorod arrays were grown on FTO via hydrothermal processes by using gallium nitrate and aluminum nitrate mixed aqueous solutions with fixed 1:1 mole ratio as precursors. With increasing the gallium nitrate precursor concentrations, the Ga/Al atom ratios in nanorod arrays increase from 0.36 to 2.08, and the length becomes much longer from 650 nm to 1.04 μm. According to the binding energy difference between Ga 2p3/2 core level and its background in x-ray photoelectron spectroscopy, the bandgap is estimated to be around 5.3 ± 0.2 eV. Al doped α-GaOOH nanorod array/FTO photoelectrochemical photodetectors show enhanced self-powered solar-blind UV photodetection properties, with the decrease of Ga precursor concentrations. The maximum responsivity at 255 nm is 0.09 mA W−1, and the fastest response time can reach 0.05 s. The improved photoresponse speed is ascribed from much shorter transportation route, accelerated carrier recombination by recombination centers, and smaller charge transfer resistance at the α-GaOOH/electrolyte interface with decreasing the gallium nitrate precursor concentrations. The stability and responsivity should be further improved. Nevertheless, this work firstly demonstrates the realization of self-powered solar-blind UV photodetection for α-GaOOH nanorod arrays on FTO via Al doping.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140926181","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}
Pub Date : 2024-05-13DOI: 10.1088/1361-6641/ad4a66
Khush Gohel, Linhui Zhou, S. Mukhopadhyay, S. Pasayat, Chirag Gupta
High power operation of high electron mobility transistors (HEMTs) is limited due to a variety of thermal resistances in the HEMT device causing self-heating effects (SHEs) in the device. To reduce the SHEs, diamond heat spreaders integrated to the device have proven efficient for heat extraction from the device. In this report using electro-thermal TCAD simulations, we demonstrate an understanding of multiway heat extraction utilizing diamond heat spreaders for improving HEMT thermal performance at high DC output power density (~40 W/mm). The impact of each heat extraction pathway is understood while considering the thermal boundary resistance between Diamond/GaN hetero-interface and optimization of the GaN buffer layer thickness. Using these findings, we simulated an AlGaN/GaN HEMT device operating at 40 W/mm DC output power while maintaining device temperature at approximately 470 - 500 K.
{"title":"Understanding of multi-way heat extraction using peripheral diamond in AlGaN/GaN HEMT by electrothermal simulations","authors":"Khush Gohel, Linhui Zhou, S. Mukhopadhyay, S. Pasayat, Chirag Gupta","doi":"10.1088/1361-6641/ad4a66","DOIUrl":"https://doi.org/10.1088/1361-6641/ad4a66","url":null,"abstract":"\u0000 High power operation of high electron mobility transistors (HEMTs) is limited due to a variety of thermal resistances in the HEMT device causing self-heating effects (SHEs) in the device. To reduce the SHEs, diamond heat spreaders integrated to the device have proven efficient for heat extraction from the device. In this report using electro-thermal TCAD simulations, we demonstrate an understanding of multiway heat extraction utilizing diamond heat spreaders for improving HEMT thermal performance at high DC output power density (~40 W/mm). The impact of each heat extraction pathway is understood while considering the thermal boundary resistance between Diamond/GaN hetero-interface and optimization of the GaN buffer layer thickness. Using these findings, we simulated an AlGaN/GaN HEMT device operating at 40 W/mm DC output power while maintaining device temperature at approximately 470 - 500 K.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140985442","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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