Acta Phys Sin Vol 60 No 1 201 017205 * GaN 2 2 71007 2 71007 2010 7 3 2010 8 10 GaN HEMTs GaN HEMTs GaN HEMTs PACS 72 80 Ey 73 40 Qv 1 field-plate GaN HEMTs HEMTs MOCVD 000 1 4 100 nm AlN 1 4 μm GaN 1 5 nm AlN 23 nm AlGaN 2 nm GaN 5 8 AlGaN GaN HEMTs Al 30% Hall 9 10 12 2 360Ω / 1418 cm 2 / V s AlGaN GaN 1 2 10 13 cm - 2 HEMTs RIE Ti / Al / Ni / Au 22 nm /140 nm /55 nm / 13 14 15 45 nm 870 40 s 16 Ni / Au / Ni 45 nm /200 nm /20 nm PECVD 60 nm SiN SiN Ti / Au 20 nm /100 GaN HEMTs nm PECVD 200 nm SiN Ti / Au 20 nm /100 nm * JY10000925002 60976068 60936005 2008ZX01002-002 E-mail mwxidian@ 126 com 2011 Chinese Physical Society 017205-1 http / / wulixb iphy ac cn
Acta Phys Sin Vol 60 No 1 201 017205 2 Keithley 4200-SCS gfp gsfp 0 6 μm 5 3 7 μm 100 μm 500 ns 0 1 ms 0 4 μm 0 2 V DSQ = 15 V V DS = 10 μm 0 9 μm 1 V V GSQ = - 8 V V GS = V m V m V DS = 10 V V GS = V m 2 SiN 2 V 55% gfp 40% gsfp 33% 15% 22% 1 GaN HEMTs 3 V DS = 15 V gfp gsfp 0 186 ma / mm 0 187 ma / mm 0 190 ma / mm 2 a b c 017205-2
Acta Phys Sin Vol 60 No 1 201 017205 V DSQ = 15 V V GSQ = - 8 V 3 3 Silvaco atlas 1 Caughey Shockley - Read - Hall AlN AlN 4 17 1418 cm 2 / V s 18 19 1 6 10 13 cm - 2 AlGaN GaN GaN AlGaN 1 10 15 cm - 3 12 20 GaN 5 10 19 cm - 3 0 3 ev 1 10-15 cm 2 GaN 1 10 17 cm - 3 0 76 ev 2 10-15 cm 2 GaN GaN 4 GaN 1 6 μm 5 7 gsfp 9 2 gsfp SiN 160 nm 4 5 GaN 017205-3
Acta Phys Sin Vol 60 No 1 201 017205 gfp 95% gsfp gfp gsfp gsfp 2 6 Simmons Taylor 22 F = pσ p v p + e n nσ n v n + pσ p v p + e n + e p e n = σ n n i v n exp E t - E i / kt e p = σ p n i v p exp E i - E t / kt n p n i σ n σ p v n v p E i E t k T n p 5 GaN GaN 7 GaN 5 gfp 7 gfp gsfp gsfp gsfp gsfp gsfp 7 GaN 6 7 GaN 6 gfp gsfp gsfp 7 017205-4
Acta Phys Sin Vol 60 No 1 201 017205 4 gfp gsfp gfp gsfp SiN 7 GaN HEMTs Kumar V Chen G Guo S P Adesida I 2006 IEEE Transactions on Electron Devices 53 1477 2 Wu Y F Moore M Wisleder T Saxler A Parikh P 2006 IEEE 64th Device Research Conference PA USA June 2006 p151 3 Wei W Hao Y Feng Q Zhang J C Zhang J F 2008 Acta Phys Sin 57 2456 in Chinese 2008 57 2456 4 Lee J W Kuliev A S Adesida I 2008 Japanese Journal of Applied Physics 47 1479 5 Koudymov A Adivarahan V Yang J Simin G Khan A A 2005 IEEE Electron Device Letters 26 704 6 Wei W Lin R B Feng Q Hao Y 2008 Acta Phys Sin 57 467 in Chinese 2008 57 467 7 Nakajima A Itagaki K Horio K 2009 Phys Status Solidi 6 2840 8 Brannick A Zakhleniuk N A Ridley B K Shealy J R Schaff W J Eastman L F 2009 IEEE Electron Device Letters 30 436 9 Daumiller I Theron D Gaquiere C Vescan A Dietrich R Wieszt A Leier H Vetury R Mishra U K Smorchkova I P Nguyen N X Kohn E 2001 IEEE Electron Device Letters 22 62 10 Xi G Y Ren F Hao Z B Wang L Li H T Jiang Y Zhao W Han Y J Luo Y 2008 Acta Phys Sin 57 7238 in Chinese 2008 57 7238 1 Tirado J M Sanchez-Rojas J L Izpura J I 2007 IEEE Transactions on Electron Devices 54 410 12 Meneghesso G Rampazzo F Kordos P Verzellesi G Zanoni E 2006 IEEE Transactions on Electron Devices 53 2932 13 Romero M F Jimenez A Sanchez J M Brana A F Gonzalez - Posada F Cuerdo R Calle F Munoz E 2008 IEEE Electron Device Letters 29 209 14 Yang L Hao Y Ma X H Quan S Hu G Z Jiang S G Yang L Y 2009 Chin Phys Lett 26 117104 15 Hu G Z Yang L Yang L Y Quan S Jiang S G Ma J G Ma X H Hao Y 2010 Chin Phys Lett 27 087302 16 Shen L Palacios T Coblenz C Corrion A Chakraborty A Fichtenbaum N Keller S Denbaars S P Speck J S Mishra U K 2006 IEEE Electron Device Letters 27 214 17 Zhou Z T Guo L W Xing Z G Ding G J Tan C L Lu L Liu J Liu X Y Jia H Q Chen H Zhou J M 2007 Acta Phys Sin 56 6013 in Chinese 2007 56 6013 18 Ambacher O Smart J Shealy J R Weimann N G Chu K Murphy M Schaff W J Eastman L F 1999 Journal of Applied Physics 85 3222 19 Piprek J 2007 Nitride Semiconductor Devices - Principles and Simulation New York Wiley-VCH p24 53 20 Faqir M Verzellesi G Chini A Fantini F Danesin F Meneghesso G Zanoni E Dua C 2008 IEEE Transactions on 017205-5
Acta Phys Sin Vol 60 No 1 201 017205 Device and Materials Reliability 8 240 2 Vetury R Zhang N Q Keller S Mishra U K 2001 IEEE Transactions on Electron Devices 48 560 22 Simmons J G Taylor G W 1971 Phys Rev B 4 502 Study on the suppression mechanism of current collapse with field-plates in GaN high-electron mobility transistors * Mao Wei Yang Cui 2 Hao Yue Zhang Jin-Cheng Liu Hong-Xia Ma Xiao-Hua 2 Wang Chong Zhang Jin-Feng Yang Lin-An Xu Sheng-Rui Bi Zhi-Wei Zhou Zhou Yang Ling Wang Hao School of Microelectronics Xidian University Key Lab of Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices Xi an 71007 China 2 School of Technical Physics Xidian University Xi an 71007 China Received 3 July 2010 revised manuscript received 10 August 2010 Abstract The physical mechanisms underlying current collapse effects in the passivated GaN high-electron mobility transistors HEMTs the gate field-plated GaN HEMTs and the gate-source field-plated GaN HEMTs are investigated in experiments and numerical device simulations And the intrinsic relationships of the current collapse with the carrier concentration the probability of traps ionization and the electric field within the cap layer are established Results show that the direction of the longitudinal electric field as well as the intensity distribution of both the transverse and longitudinal electric fields within the cap layer can be modulated effectively by the field-plates The electric field intensity near the gate is reduced and that beneath the field-plates increased Due to the effects of the field-plates on electric field the transverse movement of electrons near the gate is reduced and the longitudinal electron movement beneath the field-plates is increased These affects the electron concentration distribution and the ionization probability of the traps in the cap layer which makes field-plates effective for the reduction in the current collapse Keywords current collapse passivated devices field-plated devices probability of traps ionization PACS 72 80 Ey 73 40 Qv * Project supported by the Fundamental Research Funds for the Central Universities Grant No JY10000925002 the National Natural Science Foundation of China Grant Nos 60976068 60936005 and the National Key Science & Technology Special Project Grant No 2008ZX01002-002 E-mail mwxidian@ 126 com 017205-6