Pub Date : 2022-06-01DOI: 10.1109/CSW55288.2022.9930356
Bingjun Li, Sizhen Wang, Sam Frisone, Jiaheng He, Guanjie Cheng, Zhirong Zhang, R. Goldman, Jung Han
In this study, we compared different process-treated surfaces by building Schottky diodes, and performing photoluminescence (PL) and Rutherfold backscattering (RBSc) measurements. TBCl etched sample has a leakage behavior approaches that of the as-grown sample under both forward and reverse biases, while dry-etched surface is very leaky. On the other hand, additional TBCl etching following dry etching could improve the leakage behavior. Same trends were also observed in both PL and RBSc measurements by comparing the near-band-edge emission and displaced atoms density on the surface, respectively. Both electrical and material characterizations confirm that TBCl etching is not only a low-damage etching method, but is also capable of removing damage induced by the dry etching process.
{"title":"Low-damage, in-situ chemical etching of GaN by tertiarybutyl-chloride (TBCl)","authors":"Bingjun Li, Sizhen Wang, Sam Frisone, Jiaheng He, Guanjie Cheng, Zhirong Zhang, R. Goldman, Jung Han","doi":"10.1109/CSW55288.2022.9930356","DOIUrl":"https://doi.org/10.1109/CSW55288.2022.9930356","url":null,"abstract":"In this study, we compared different process-treated surfaces by building Schottky diodes, and performing photoluminescence (PL) and Rutherfold backscattering (RBSc) measurements. TBCl etched sample has a leakage behavior approaches that of the as-grown sample under both forward and reverse biases, while dry-etched surface is very leaky. On the other hand, additional TBCl etching following dry etching could improve the leakage behavior. Same trends were also observed in both PL and RBSc measurements by comparing the near-band-edge emission and displaced atoms density on the surface, respectively. Both electrical and material characterizations confirm that TBCl etching is not only a low-damage etching method, but is also capable of removing damage induced by the dry etching process.","PeriodicalId":382443,"journal":{"name":"2022 Compound Semiconductor Week (CSW)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120952003","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 : 2022-06-01DOI: 10.1109/CSW55288.2022.9930418
K. Reilly, S. Seth, F. F. Ince, A. Kalapala, T. Rotter, Zhongue Liu, E. Renteria, Weidong Zhou, G. Balakrishnan
Molecular Beam Epitaxy (MBE) is used for fabrication of Photonic Crystal Surface Emitting Lasers (PCSELs). Two methods of PCSEL fabrication are explored and compared: epitaxial regrowth and non-regrowth. Optically pumped and electrically injected devices are demonstrated by epitaxial regrowth.
{"title":"Fabrication Methods for Photonic Crystal Surface Emitting Lasers (PCSELs) by Molecular Beam Epitaxy","authors":"K. Reilly, S. Seth, F. F. Ince, A. Kalapala, T. Rotter, Zhongue Liu, E. Renteria, Weidong Zhou, G. Balakrishnan","doi":"10.1109/CSW55288.2022.9930418","DOIUrl":"https://doi.org/10.1109/CSW55288.2022.9930418","url":null,"abstract":"Molecular Beam Epitaxy (MBE) is used for fabrication of Photonic Crystal Surface Emitting Lasers (PCSELs). Two methods of PCSEL fabrication are explored and compared: epitaxial regrowth and non-regrowth. Optically pumped and electrically injected devices are demonstrated by epitaxial regrowth.","PeriodicalId":382443,"journal":{"name":"2022 Compound Semiconductor Week (CSW)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121276631","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 : 2022-06-01DOI: 10.1109/CSW55288.2022.9930384
Kilian Baril, P. Coulon, M. Mrad, L. Dupré, G. Feuillet, M. Charles, C. Gourgon, P. Vennégués, B. Alloing, J. Z. Pérez
This work presents the use of nanopendeo-epitaxy of gallium nitride (GaN) on Silicon-On-Insulator (SOI) nano-pillars to produce 20x20 μm2 low threading dislocation density (TDD) GaN platelets, with a TDD <3×108 cm−2 for their subsequent use as templates for GaN microLEDs. After discussing the general growth strategy, the correlation between optical and structural characterizations will illustrate the behavior of dislocations from the initial GaN/SOI pillars to the GaN platelets surface. Finally, we demonstrate that a state of the art TDD for GaN on silicon lower than 3×108 cm−2 can be achieved by changing the growth mode in Metal Organic Vapor Phase Epitaxy (MOVPE).
{"title":"GaN growth by MOVPE on patterned SOI substrates: from high-quality GaN platelets to micro LEDs","authors":"Kilian Baril, P. Coulon, M. Mrad, L. Dupré, G. Feuillet, M. Charles, C. Gourgon, P. Vennégués, B. Alloing, J. Z. Pérez","doi":"10.1109/CSW55288.2022.9930384","DOIUrl":"https://doi.org/10.1109/CSW55288.2022.9930384","url":null,"abstract":"This work presents the use of nanopendeo-epitaxy of gallium nitride (GaN) on Silicon-On-Insulator (SOI) nano-pillars to produce 20x20 μm2 low threading dislocation density (TDD) GaN platelets, with a TDD <3×108 cm−2 for their subsequent use as templates for GaN microLEDs. After discussing the general growth strategy, the correlation between optical and structural characterizations will illustrate the behavior of dislocations from the initial GaN/SOI pillars to the GaN platelets surface. Finally, we demonstrate that a state of the art TDD for GaN on silicon lower than 3×108 cm−2 can be achieved by changing the growth mode in Metal Organic Vapor Phase Epitaxy (MOVPE).","PeriodicalId":382443,"journal":{"name":"2022 Compound Semiconductor Week (CSW)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126010947","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}
Phase pure single crystal α-(AlxGa1−x)2O3 thin films are successfully grown on m-plane sapphire substrate via MOCVD. Comprehensive characterization by XRD, RSM mapping, atomic resolution STEM, Raman spectroscopy, SEM, AFM and XPS measurements reveal high quality epitaxial growth of α-(AlxGa1−x)2O3 thin films over the entire Al composition range (x=0–100%) and α-GaO/AlGaO superlattice structures with smooth surface morphology, sharp interfaces, and homogenous Al distribution. The bandgap energies of 5.41 eV (x=0) to 8.81 eV (x=1) are extracted from XPS measurements. The determined band offsets reveal a type-I band alignment at the α-AlGaO/GaOinterfaces with valance and conduction band offsets of 0.27 eV and 3.13 eV between α-Ga2O3 and α-Al2O3, respectively.
采用MOCVD技术在m平面蓝宝石衬底上成功生长出相纯单晶α-(AlxGa1−x)2O3薄膜。通过XRD, RSM作图,原子分辨率STEM,拉曼光谱,SEM, AFM和XPS测量等综合表征表明,α-(AlxGa1−x)2O3薄膜在整个Al成分范围(x= 0-100%)内具有高质量的外延生长,α- gao /AlGaO超晶格结构具有光滑的表面形貌,尖锐的界面和均匀的Al分布。从XPS测量中提取了5.41 eV (x=0) ~ 8.81 eV (x=1)的带隙能量。α-Ga2O3和α-Al2O3之间的价带和导带偏移量分别为0.27 eV和3.13 eV, α-Al2O3与α-Al2O3界面处的能带偏移量为i型。
{"title":"MOCVD Epitaxy of α-(AlxGa1−x)2O3 (x =0–100%) on m-Plane Sapphire Substrate","authors":"A. Bhuiyan, Zixuan Feng, Hsien-Lien Huang, Lingyu Meng, Jinwoo Hwang, Hongping Zhao","doi":"10.1109/csw55288.2022.9930429","DOIUrl":"https://doi.org/10.1109/csw55288.2022.9930429","url":null,"abstract":"Phase pure single crystal α-(Al<inf>x</inf>Ga<inf>1−x</inf>)<inf>2</inf>O<inf>3</inf> thin films are successfully grown on m-plane sapphire substrate via MOCVD. Comprehensive characterization by XRD, RSM mapping, atomic resolution STEM, Raman spectroscopy, SEM, AFM and XPS measurements reveal high quality epitaxial growth of α-(Al<inf>x</inf>Ga<inf>1−x</inf>)<inf>2</inf>O<inf>3</inf> thin films over the entire Al composition range (x=0–100%) and α-GaO/AlGaO superlattice structures with smooth surface morphology, sharp interfaces, and homogenous Al distribution. The bandgap energies of 5.41 eV (x=0) to 8.81 eV (x=1) are extracted from XPS measurements. The determined band offsets reveal a type-I band alignment at the α-AlGaO/GaOinterfaces with valance and conduction band offsets of 0.27 eV and 3.13 eV between α-Ga<inf>2</inf>O<inf>3</inf> and α-Al<inf>2</inf>O<inf>3</inf>, respectively.","PeriodicalId":382443,"journal":{"name":"2022 Compound Semiconductor Week (CSW)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122261191","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 : 2022-06-01DOI: 10.1109/CSW55288.2022.9930445
O. Fesiienko, C. Petit-Etienne, M. Darnon, A. Soltani, H. Maher, E. Pargon
Two low-damage plasma etching processes have been investigated to evaluate their impact on the integrity of the AlGaN layer during the SiN gate opening process of Metal Insulator Semiconductor High Electron Mobility Transistors (MIS-HEMT). We show that the low ion energy fluorocarbon plasma presents an infinite SiN/AlGaN etch selectivity despite significant surface modifications. In contrast, the smart etch process, that alternates H2 plasma-based surface modification with chemical removal of the modified surface, preserves the surface of AlGaN. However it can lead to AlGaN recess due to over-implantation during the H2 plasma step. Finally, we show that a KOH post etchi treatment removes plasma-induced damages. Therefore, combining the smart etch process with a KOH post etch treatment offers an interesting solution for SiN patterning over AlGaN with minimized surface modification and restored AlGaN surface quality.
{"title":"Development of low-damage plasma etching processes for preserving AlGaN/GaN heterostructure integrity in MIS HEMT","authors":"O. Fesiienko, C. Petit-Etienne, M. Darnon, A. Soltani, H. Maher, E. Pargon","doi":"10.1109/CSW55288.2022.9930445","DOIUrl":"https://doi.org/10.1109/CSW55288.2022.9930445","url":null,"abstract":"Two low-damage plasma etching processes have been investigated to evaluate their impact on the integrity of the AlGaN layer during the SiN gate opening process of Metal Insulator Semiconductor High Electron Mobility Transistors (MIS-HEMT). We show that the low ion energy fluorocarbon plasma presents an infinite SiN/AlGaN etch selectivity despite significant surface modifications. In contrast, the smart etch process, that alternates H2 plasma-based surface modification with chemical removal of the modified surface, preserves the surface of AlGaN. However it can lead to AlGaN recess due to over-implantation during the H2 plasma step. Finally, we show that a KOH post etchi treatment removes plasma-induced damages. Therefore, combining the smart etch process with a KOH post etch treatment offers an interesting solution for SiN patterning over AlGaN with minimized surface modification and restored AlGaN surface quality.","PeriodicalId":382443,"journal":{"name":"2022 Compound Semiconductor Week (CSW)","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132101001","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 : 2022-06-01DOI: 10.1109/CSW55288.2022.9930434
A. Ajay, H. Jeong, H. Yu, T. Schreitmüller, D. Ruhstorfer, N. Mukhundhan, M. Döblinger, G. Koblmüller
In this work, we utilize selective area growth of GaAs(Sb):(Si) NWs using molecular beam epitaxy in the non-VLS growth regime to develop pure zinc blende NWs with high uniformity, yield, aspect ratio and morphology control which are of utmost importance for scalability and commercialization of NW technology. We observe a surprising increased axial growth in the presence of Sb (1–2%) that contrasts the commonly believed enhancement in radial growth due to the surfactant effect of Sb. The droplet-free non-VLS growth opens further suitable pathways for pristine axial heterostructures, where first data of GaAsSb/InGaAs axial heterostructures and their distinct luminescence features will be shown. These results indicate a change in paradigm for non-VLS NWs with highly uniform axial growth that would be ideal for III-V NW integration on Si and the exploration of atomically abrupt NW heterostructures with other materials.
{"title":"Highly uniform non-VLS GaAsSb nanowires: Towards enhanced axial growth and axial heterostructures","authors":"A. Ajay, H. Jeong, H. Yu, T. Schreitmüller, D. Ruhstorfer, N. Mukhundhan, M. Döblinger, G. Koblmüller","doi":"10.1109/CSW55288.2022.9930434","DOIUrl":"https://doi.org/10.1109/CSW55288.2022.9930434","url":null,"abstract":"In this work, we utilize selective area growth of GaAs(Sb):(Si) NWs using molecular beam epitaxy in the non-VLS growth regime to develop pure zinc blende NWs with high uniformity, yield, aspect ratio and morphology control which are of utmost importance for scalability and commercialization of NW technology. We observe a surprising increased axial growth in the presence of Sb (1–2%) that contrasts the commonly believed enhancement in radial growth due to the surfactant effect of Sb. The droplet-free non-VLS growth opens further suitable pathways for pristine axial heterostructures, where first data of GaAsSb/InGaAs axial heterostructures and their distinct luminescence features will be shown. These results indicate a change in paradigm for non-VLS NWs with highly uniform axial growth that would be ideal for III-V NW integration on Si and the exploration of atomically abrupt NW heterostructures with other materials.","PeriodicalId":382443,"journal":{"name":"2022 Compound Semiconductor Week (CSW)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132207950","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 : 2022-06-01DOI: 10.1109/CSW55288.2022.9930466
Tao Li, Jingan Zhou, K. Fu, Mingfei Xu, Ziyi He, Yuji Zhao
In this work, the properties of edge states within h-BN topological photonic structures in the UV-Vis spectrum are investigated using full-field electromagnetic simulation based on the Finite-Difference Time-Domain (FDTD) method. An h-BN photonic structure with non-trivial band topology is constructed by deforming a photonic crystal with a 6-fold symmetric honeycomb-like lattice. By pairing the topological structure with its topologically trivial counterpart, we observed the topologically protected edge states propagating along the interface between the two structures. The stability of edge states is manifested by their robust transport through a zigzag waveguide with eight 120° bends. The edge states’ polarization-resolved unidirectionality differentiates themselves from guided modes supported by the line defects within traditional photonic crystals. These findings will lay a basis for the interaction of topological photonic phenomena and other engaging optical properties of h-BN in the UV-Vis spectrum.
{"title":"Edge States Propagation within h-BN Topological Photonic Structures in UV-Vis Spectrum","authors":"Tao Li, Jingan Zhou, K. Fu, Mingfei Xu, Ziyi He, Yuji Zhao","doi":"10.1109/CSW55288.2022.9930466","DOIUrl":"https://doi.org/10.1109/CSW55288.2022.9930466","url":null,"abstract":"In this work, the properties of edge states within h-BN topological photonic structures in the UV-Vis spectrum are investigated using full-field electromagnetic simulation based on the Finite-Difference Time-Domain (FDTD) method. An h-BN photonic structure with non-trivial band topology is constructed by deforming a photonic crystal with a 6-fold symmetric honeycomb-like lattice. By pairing the topological structure with its topologically trivial counterpart, we observed the topologically protected edge states propagating along the interface between the two structures. The stability of edge states is manifested by their robust transport through a zigzag waveguide with eight 120° bends. The edge states’ polarization-resolved unidirectionality differentiates themselves from guided modes supported by the line defects within traditional photonic crystals. These findings will lay a basis for the interaction of topological photonic phenomena and other engaging optical properties of h-BN in the UV-Vis spectrum.","PeriodicalId":382443,"journal":{"name":"2022 Compound Semiconductor Week (CSW)","volume":"4 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132227870","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 : 2022-06-01DOI: 10.1109/csw55288.2022.9930358
T. Beckerwerth, Arbnore Berisha, T. Simoneit, P. Runge, M. Schell
We present a Multiple Quantum Well (MQW) based high-speed photodetector with a responsivity for TE polarized light of 0.76 A/W and a polarization extinction ratio (PER) of 4.5 dB at a wavelength of 1550 nm and above 20 dB at 1580 nm. As a result of minimizing the valence band offset and optimizing the number of QWs, the photodiode shows a high 3dB-bandwidth of 36 GHz.
我们提出了一种基于多量子阱(MQW)的高速光电探测器,其对TE偏振光的响应率为0.76 a /W,偏振消光比(PER)在波长为1550 nm时为4.5 dB,在波长为1580 nm时为20 dB以上。由于最小化了价带偏移和优化了量子波数,光电二极管显示出36 GHz的高3db带宽。
{"title":"High-Speed Multiple Quantum Well Photodetector for Polarization Diverse Detection","authors":"T. Beckerwerth, Arbnore Berisha, T. Simoneit, P. Runge, M. Schell","doi":"10.1109/csw55288.2022.9930358","DOIUrl":"https://doi.org/10.1109/csw55288.2022.9930358","url":null,"abstract":"We present a Multiple Quantum Well (MQW) based high-speed photodetector with a responsivity for TE polarized light of 0.76 A/W and a polarization extinction ratio (PER) of 4.5 dB at a wavelength of 1550 nm and above 20 dB at 1580 nm. As a result of minimizing the valence band offset and optimizing the number of QWs, the photodiode shows a high 3dB-bandwidth of 36 GHz.","PeriodicalId":382443,"journal":{"name":"2022 Compound Semiconductor Week (CSW)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130988422","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 : 2022-06-01DOI: 10.1109/CSW55288.2022.9930442
J. A. M. Fordyce, D. Díaz-Thomas, T. Piwoński, A. Baranov, L. O’Faolain, L. Cerutti
The first demonstration of single-mode behaviour of interband cascade lasers (ICLs) using a slotted waveguide is presented. Side mode suppression ratios (SMSRs) between 10 – 15 dB are observed for temperatures of 15 – 21.5°C for injection currents near the maximum power output, before the thermal rollover, and after this point. These measurements provide a benchmark for the amount of modulation of the refractive index in the cladding required to interact with the longitudinal cavity modes which is needed to extend the range of conditions of single mode emission. The spectra is observed over different parameters such as number of slots, slot depth, slot spacing, temperature and injection current.
{"title":"DFB Style Slotted Waveguide Interband Cascade Lasers","authors":"J. A. M. Fordyce, D. Díaz-Thomas, T. Piwoński, A. Baranov, L. O’Faolain, L. Cerutti","doi":"10.1109/CSW55288.2022.9930442","DOIUrl":"https://doi.org/10.1109/CSW55288.2022.9930442","url":null,"abstract":"The first demonstration of single-mode behaviour of interband cascade lasers (ICLs) using a slotted waveguide is presented. Side mode suppression ratios (SMSRs) between 10 – 15 dB are observed for temperatures of 15 – 21.5°C for injection currents near the maximum power output, before the thermal rollover, and after this point. These measurements provide a benchmark for the amount of modulation of the refractive index in the cladding required to interact with the longitudinal cavity modes which is needed to extend the range of conditions of single mode emission. The spectra is observed over different parameters such as number of slots, slot depth, slot spacing, temperature and injection current.","PeriodicalId":382443,"journal":{"name":"2022 Compound Semiconductor Week (CSW)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125051932","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 : 2022-06-01DOI: 10.1109/CSW55288.2022.9930457
A. Papamichail, Axel R. Persson, Steffen Ricther, P. Kühne, P. O. Persson, M. Thorsell, H. Hjelmgren, N. Rorsman, V. Darakchieva
Although AlGaN/GaN HEMTs with high power and current gain have been demonstrated in RF device applications, at high signal operation they show an inherent non-linear behavior which leads to gain compression and signal distortion. Polarization-doped AlGaN/GaN HEMTs, with a compositionally graded channel enables a linear response improvement through formation of a 3-D electron gas. In this work, we develop the growth process for graded channel HEMTs in a hot-wall MOCVD reactor. Control of the grading profile is established through growth parameter tuning. Afterwards, analysis by EDS allows for precise determination of Al composition across the channel. Conventional and graded channel HEMT structures were fabricated and characterized. Furthermore, the sheet resistance, carrier density and mobility in HEMT structures with different grading profiles are compared and discussed. The conventional (non-graded) structure revealed the highest electron mobility of ~2350 cm2/V.s, which is among the highest values reported.
{"title":"Compositionally graded channel HEMTs towards improved linearity for low-noise RF amplifiers","authors":"A. Papamichail, Axel R. Persson, Steffen Ricther, P. Kühne, P. O. Persson, M. Thorsell, H. Hjelmgren, N. Rorsman, V. Darakchieva","doi":"10.1109/CSW55288.2022.9930457","DOIUrl":"https://doi.org/10.1109/CSW55288.2022.9930457","url":null,"abstract":"Although AlGaN/GaN HEMTs with high power and current gain have been demonstrated in RF device applications, at high signal operation they show an inherent non-linear behavior which leads to gain compression and signal distortion. Polarization-doped AlGaN/GaN HEMTs, with a compositionally graded channel enables a linear response improvement through formation of a 3-D electron gas. In this work, we develop the growth process for graded channel HEMTs in a hot-wall MOCVD reactor. Control of the grading profile is established through growth parameter tuning. Afterwards, analysis by EDS allows for precise determination of Al composition across the channel. Conventional and graded channel HEMT structures were fabricated and characterized. Furthermore, the sheet resistance, carrier density and mobility in HEMT structures with different grading profiles are compared and discussed. The conventional (non-graded) structure revealed the highest electron mobility of ~2350 cm2/V.s, which is among the highest values reported.","PeriodicalId":382443,"journal":{"name":"2022 Compound Semiconductor Week (CSW)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126168706","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}