Optimization design on breakdown voltage of AlGaN/GaN high-electron mobility transistor  

作　　者：刘阳 柴常春 史春蕾 樊庆扬 刘彧千 

机构地区：[1]School of Microelectronics,Xidian University,Key Laboratory of Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices

出　　处：《Journal of Semiconductors》2016年第12期40-44,共5页半导体学报（英文版）

基　　金：Project supported by the National Basic Research Program of China(No.2014CB339900);the Open Fund of Key Laboratory of Complex Electromagnetic Environment Science and Technology,China Academy of Engineering Physics(No.2015-0214.XY.K)

摘　　要：Simulations are carried out to explore the possibility of achieving high breakdown voltage of Gain HEMT （high-electron mobility transistor）. GaN cap layers with gradual increase in the doping concentration from 2 x 10^16 to 5 x 10^19 cm-3 of N-type and P-type cap are investigated, respectively. Simulation results show that HEMT with P-doped GaN cap layer shows more potential to achieve higher breakdown voltage than N-doped GaN cap layer under the same doping concentration. This is because the ionized net negative space charges in P-GaN cap layer could modulate the surface electric field which makes more contribution to RESURF effect. Furthermore, a novel GaN/A1GaN/GaN HEMT with P-doped GaN buried layer in GaN buffer between gate and drain electrode is proposed. It shows enhanced performance. The breakdown voltage of the proposed structure is 640 V which is increased by 12% in comparison to UID （un-intentionally doped） GaN/A1GaN/GaN HEMT. We calculated and analyzed the distribution of electrons＇ density. It is found that the depleted region is wider and electric field maximum value is induced at the left edge of buried layer. So the novel structure with P-doped GaN buried layer embedded in GaN buffer has the better improving characteristics of the power devices.Simulations are carried out to explore the possibility of achieving high breakdown voltage of Gain HEMT （high-electron mobility transistor）. GaN cap layers with gradual increase in the doping concentration from 2 x 10^16 to 5 x 10^19 cm-3 of N-type and P-type cap are investigated, respectively. Simulation results show that HEMT with P-doped GaN cap layer shows more potential to achieve higher breakdown voltage than N-doped GaN cap layer under the same doping concentration. This is because the ionized net negative space charges in P-GaN cap layer could modulate the surface electric field which makes more contribution to RESURF effect. Furthermore, a novel GaN/A1GaN/GaN HEMT with P-doped GaN buried layer in GaN buffer between gate and drain electrode is proposed. It shows enhanced performance. The breakdown voltage of the proposed structure is 640 V which is increased by 12% in comparison to UID （un-intentionally doped） GaN/A1GaN/GaN HEMT. We calculated and analyzed the distribution of electrons＇ density. It is found that the depleted region is wider and electric field maximum value is induced at the left edge of buried layer. So the novel structure with P-doped GaN buried layer embedded in GaN buffer has the better improving characteristics of the power devices.

关 键 词：GaN HEMT optimization design breakdown voltage cap layer 

分 类 号：TN386[电子电信—物理电子学]