G. Koley, V. Tilak, H. Cha, L. Eastman, M. Spencer
{"title":"Surface trapping effects observed in AlGaN/GaN HFETs and heterostructures","authors":"G. Koley, V. Tilak, H. Cha, L. Eastman, M. Spencer","doi":"10.1109/LECHPD.2002.1146789","DOIUrl":"https://doi.org/10.1109/LECHPD.2002.1146789","url":null,"abstract":"We have observed very slow surface potential transients in AlGaN/GaN HFETs induced by high drain and gate bias stresses. The surface potential has been observed to change as much as 2.5 V near the gate. It is proposed that the change in surface potential is caused by electrons that tunnel from the gate and get trapped at the surface states. The increase in the net negative charge at the surface raises the surface barrier, which in turn reduces the 2DEG concentration. Simultaneous measurements of surface electrostatic potential and drain current indicate that the transients have similar transient responses and are therefore related. A spatial map of the surface potential change after stress with respect to time shows that maximum changes occur close to the gate. Exposure to UV laser light completely eliminates the transients, while large reduction in transient magnitude has been observed for devices passivated with SiN/sub x/. Contrary to the gate and drain stress, UV laser exposure of AlGaN/GaN heterostructure samples has been observed to reduce the surface barrier, which slowly increases following a stretched exponential type transient after the laser is switched off. Such an observation is explained by the creation of electron-hole pairs, which decrease the net charge dipole across the AlGaN barrier and lower the barrier. The transient response is modeled by thermionic emission of electrons from the interface, which recombine with the holes trapped at the surface.","PeriodicalId":137839,"journal":{"name":"Proceedings. IEEE Lester Eastman Conference on High Performance Devices","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131426058","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}
P. Fay, J. Schulman, S. Thomas, D. Chow, Y. Boegeman, K. Holabird
{"title":"Performance and modeling of antimonide-based heterostructure backward diodes for millimeter-wave detection","authors":"P. Fay, J. Schulman, S. Thomas, D. Chow, Y. Boegeman, K. Holabird","doi":"10.1109/LECHPD.2002.1146772","DOIUrl":"https://doi.org/10.1109/LECHPD.2002.1146772","url":null,"abstract":"Heterostructure backward diodes have been fabricated and characterized for use as zero-bias millimeter-wave detectors. Sensitive detector performance in the W-band was achieved by scaling the active area to 1.5/spl times/1.5 /spl mu/m/sup 2/ through the use of high-resolution i-line stepper lithography. Responsivities of 2450 V/W and 2341 V/W were measured on-wafer at 95 GHz and 110 GHz, respectively. The detectors exhibit good detection linearity, with 0.8 dB compression, measured at an RF power of 4 /spl mu/W at 95 GHz. A nonlinear device model, based on bias-dependent millimeter-wave S-parameter measurements, has been developed. The model is consistent with the measured frequency response, responsivity, and detector compression characteristics. Extrapolation using the model to reduced device dimensions suggests that this device technology should provide appreciable responsivities (>1000 V/W) at frequencies through G-band and beyond.","PeriodicalId":137839,"journal":{"name":"Proceedings. IEEE Lester Eastman Conference on High Performance Devices","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124996864","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}
T. Adam, S. Shi, S. Ray, R. Troeger, D. Prather, J. Kolodzey
{"title":"The design and fabrication of microdisk resonators for terahertz frequency operation","authors":"T. Adam, S. Shi, S. Ray, R. Troeger, D. Prather, J. Kolodzey","doi":"10.1109/LECHPD.2002.1146780","DOIUrl":"https://doi.org/10.1109/LECHPD.2002.1146780","url":null,"abstract":"The design and fabrication of resonators and waveguides, operating at THz frequencies are reported. Resonance frequencies, mode confinement, quality factors, and stop-bands were calculated for resonators with and without photonic elements. The estimations show that very narrow modes can exist within the propagation bandgap of a photonic lattice. Microdisk devices were designed and fabricated for high-quality whispering-gallery modes centered around 10 THz. Combined with silicon-germanium quantum wells grown by molecular beam epitaxy, these resonators are promising candidates for silicon-based miniature far-infrared lasers.","PeriodicalId":137839,"journal":{"name":"Proceedings. IEEE Lester Eastman Conference on High Performance Devices","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114724433","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}
A. Conway, P. Asbeck, J. Jensen, W. Wong, M. Mokhtari, J. Moon
{"title":"Compact circuit model of GaN HFETs for mixed signal circuits","authors":"A. Conway, P. Asbeck, J. Jensen, W. Wong, M. Mokhtari, J. Moon","doi":"10.1109/LECHPD.2002.1146743","DOIUrl":"https://doi.org/10.1109/LECHPD.2002.1146743","url":null,"abstract":"This work presents a comprehensive compact circuit model of GaN HFETs for mixed signal applications. Self-heating and trapping effects are included in the model. Model parameters can be determined by fitting measured data, or estimated analytically based on geometrical dimensions and layer structure. Good agreement has been found with measured characteristics from DC to RF.","PeriodicalId":137839,"journal":{"name":"Proceedings. IEEE Lester Eastman Conference on High Performance Devices","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121679178","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}
I. Smorchkova, M. Wojtowicz, R. Tsai, R. Sandhu, M. Barsky, C. Namba, Po-Hsin Liu, R. Dia, M. Truong, D. Ko, J. Wang, Huei Wang, A. Khan
{"title":"AlGaN/GaN HEMT high-power and low-noise performance at f/spl ges/20 GHz","authors":"I. Smorchkova, M. Wojtowicz, R. Tsai, R. Sandhu, M. Barsky, C. Namba, Po-Hsin Liu, R. Dia, M. Truong, D. Ko, J. Wang, Huei Wang, A. Khan","doi":"10.1109/LECHPD.2002.1146783","DOIUrl":"https://doi.org/10.1109/LECHPD.2002.1146783","url":null,"abstract":"Reports on the power and noise performance of AlGaN/GaN HEMTs in the K (18-27 GHz) band. At 20 GHz, a record CW output power of 2 W with an associated gain of 8 dB and PAE of 33% has been achieved on an 8-finger 0.2 /spl mu/m/spl times/500 /spl mu/m device. Minimum noise figure of 1.4 dB has been achieved on a 0.15 /spl mu/m/spl times/200 /spl mu/m device at 26 GHz. The data demonstrate the viability of AlGaN/GaN HEMTs for high-frequency power and LNA applications.","PeriodicalId":137839,"journal":{"name":"Proceedings. IEEE Lester Eastman Conference on High Performance Devices","volume":"130 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115365808","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}
{"title":"Inversion channel MOSFETs in 3C-SiC on silicon","authors":"J. Wan, M. Capano, M. Melloch, J. Cooper","doi":"10.1109/LECHPD.2002.1146735","DOIUrl":"https://doi.org/10.1109/LECHPD.2002.1146735","url":null,"abstract":"Abstract : As a substrate material, single crystal SiC wafers are commercially available in diameters up to 75 mm, whereas silicon wafers a?e available in diameters of 200-300 mm. SiC wafers remain quite expensive compared to silicon, and contain%troublesome densities of micropipes that limit the yield of large devices. In the past, several groups have attempted to circumvent these problems by fabricating devices in 3C-SiC films grown epitaxially on silicon substrates, with limited success. However, in this paper we report new results demonstrating high quality inversion channel MOSFETs in 3C-SiC films on silicon. The inversion channel mobility of SiC MOSFETs has been limited to < 50 cm2JVs in the 4H polytype and < 100 cm2fVs in the 6H polytype by a high density of interface states in the upper half of the bandgap. Because of its narrower bandgap, the 3C polytype of SiC is expected to have lower interface state density, leading to higher channel mobilities. We fabricated lateral n-channel MOSFETs in 6 pin p-type epilayers of 3C-SiC grown on 20 off-axis Si(001) substrates. The epilayers were subsequently polished to improve surface smoothness, leaving a 3 %im layer. Sacrificial oxidation was then performed to remove damage caused by polishing. Source and drains were formed by implanting phosphorus and activating at 1250 0C for 30 minutes in argon. The gate oxide was formed by wet oxidation at 1150 0C for 30 minutes, followed by re-oxidation in wet O2 at 950 0C for two hours. A polysilicon gate was deposited by LPCVD and doped by spin-on dopant. Ohmic contacts are unannealed nickel. The resulting MOSFETs show excellent transistor behavior, with good current saturation, a threshold voltage of 1.6 V, and a peak channel mobility of 170 cm2/Vs.","PeriodicalId":137839,"journal":{"name":"Proceedings. IEEE Lester Eastman Conference on High Performance Devices","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115637992","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}
B. Green, V. Kaper, V. Tilak, J. Shealy, L. Eastman
{"title":"Dynamic loadline analysis of AlGaN/GaN HEMTs","authors":"B. Green, V. Kaper, V. Tilak, J. Shealy, L. Eastman","doi":"10.1109/LECHPD.2002.1146786","DOIUrl":"https://doi.org/10.1109/LECHPD.2002.1146786","url":null,"abstract":"Surface trapping has been identified as a mechanism for lower than expected output power for experimental AlGaN/GaN HEMTs devices. This paper presents dynamic loadline analysis as a means of understanding device behavior that limits large signal performance. From observations of measured data, a model for bias-dependent drain resistance caused by trap-induced space-charge in the ungated region on the drain side of the gate is proposed. This bias-dependent drain resistance model is implemented in conjunction with a Curtice-cubic analytical transistor model to simulate the observed behavior.","PeriodicalId":137839,"journal":{"name":"Proceedings. IEEE Lester Eastman Conference on High Performance Devices","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127753993","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}
{"title":"Lessons in compound semiconductor device development","authors":"Utkarsh Mishra","doi":"10.1109/LECHPD.2002.1146725","DOIUrl":"https://doi.org/10.1109/LECHPD.2002.1146725","url":null,"abstract":"This paper is a mixture of personal opinion and technical fact merged to serve as a general guideline for compound semiconductor device choices. It may be construed as opinionated and contain several generalizations, but it is a result of the path taken by the author and results learned. The crucial importance of materials research in device development is the most important theme in the paper. Also, the need to minimize the complexity of device fabrication is also emphasized.","PeriodicalId":137839,"journal":{"name":"Proceedings. IEEE Lester Eastman Conference on High Performance Devices","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127554105","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}
{"title":"AlGaAsSb-InGaAsSb-GaSb epitaxial heterostructures for uncooled infrared detectors","authors":"O. Sulima, S. Datta, J. A. Cox, M. Mauk, B. Rafol","doi":"10.1109/LECHPD.2002.1146768","DOIUrl":"https://doi.org/10.1109/LECHPD.2002.1146768","url":null,"abstract":"Lattice matched n-type AlGaAsSb-InGaAsSb-GaSb heterostructures for uncooled infrared detectors, including separate absorption and multiplication avalanche photodiodes (SAM-APD), as well as low-voltage InGaAsSb APDs, were grown using inexpensive liquid phase epitaxy. Formation of the pn-junction was performed through diffusion of Zn from the vapor phase. Responsivity at /spl lambda/=2 /spl mu/m as high as 3.5 A/W was achieved in InGaAsSb APD biased at 8 V with the avalanche multiplication starting at 6 V. Our calculations have shown that the above parameters can result in a NEP value as low as 1/spl times/10/sup -12/ W or D* value as high as 2/spl times/10/sup 10/ cm/spl times/Hz/sup 1/2//W at room temperature for 400 /spl mu/m diameter (200 /spl mu/m diameter photoactive area) APDs.","PeriodicalId":137839,"journal":{"name":"Proceedings. IEEE Lester Eastman Conference on High Performance Devices","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128028494","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}
{"title":"High-performance power BJTs in 4H-SiC","authors":"Chih-Fang Huang, J. Cooper","doi":"10.1109/LECHPD.2002.1146731","DOIUrl":"https://doi.org/10.1109/LECHPD.2002.1146731","url":null,"abstract":"In this paper, we summarize recent progress in 4H-SiC BJTs at Purdue University. For 50 /spl mu/m collector devices, BV/sub CEO/>3,200 V is achieved. Large devices (active area=1.05 mm/sup 2/) exhibit common emitter current gain /spl beta/ of around 15, and. specific on-resistance R/sub ON,SP/ of 78 m/spl Omega//cm/sup 2/. Smaller devices (active area=0.0072 mm/sup 2/) have /spl beta/ of 20 and R/sub ON,SP/ of 28 m/spl Omega//cm/sup 2/. For 20 /spl mu/m collector devices, /spl beta/s greater than 50 and R/sub ON,SP/ around 26 m/spl Omega//cm/sup 2/ are observed. The blocking voltage is low (500-700 V) for these devices because of aluminum spiking during the base contact anneal. The observed positive temperature coefficient of R/sub ON,SP/ and negative coefficient of /spl beta/ show that 4H-SiC BJTs can be safely operated in parallel connection. We also observe that /spl beta/ decreases as the spacing between base contact implant and emitter finger is reduced. We attribute this to recombination at defect sites in the p+ implanted base contact.","PeriodicalId":137839,"journal":{"name":"Proceedings. IEEE Lester Eastman Conference on High Performance Devices","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131367649","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}