终端场板结构对GaN基肖特基势垒二极管击穿电压的影响  

Influence of Terminal Field Plate on Breakdown Voltage in GaN-Based Schottky Barrier Diode

作　　者：朱友华[1] 薛海峰 王美玉[1] 李毅[1] ZHU Youhua;XUE Haifeng;WANG Meiyu;LI Yi(School of Information Science and Technology,Nantong University,Nantong 226019,China)

机构地区：[1]南通大学信息科学技术学院,江苏南通226019

出　　处：《南通大学学报（自然科学版）》2021年第3期82-87,共6页Journal of Nantong University(Natural Science Edition)　

基　　金：国家自然科学基金面上项目(61874168);江苏高校品牌专业建设工程资助项目(PPZY2015B135);江苏省产学研项目(BY2019114)。

摘　　要：为了提高肖特基势垒二极管(Schottky barrier diode,SBD)的击穿电压(breakdown voltage,BV),系统研究了终端场板结构的GaN-SBD。基于Silvaco TCAD软件,采用控制变量法即分别在不同场板长度(L_(FP))和绝缘层厚度(T_(FP))及GaN漂移区掺杂浓度(N_(D))条件下仿真了器件的击穿电压,通过器件表面电场分布情况确认了BV的变化趋势。结果表明:当T_(FP)=0.3μm,N_(D)=1×10^(16)cm^(-3),L_(FP)从0增加到2.0μm时,SBD的BV逐渐升高,在L_(FP)=1.6μm时达到阈值;当L_(FP)=1.6μm,N_(D)=1×10^(16)cm^(-3),T_(FP)从0.1μm增加到0.4μm,SBD的BV先上升后减小,在T_(FP)=0.3μm时达到最大值;当L_(FP)=1.6μm,T_(FP)=0.3μm,N_(D)从1×10^(16)cm^(-3)增加到1×10^(19)cm^(-3)时,SBD的BV逐渐减小。相比于传统无场板型GaN-SBD,该终端场板型GaN-SBD的BV在L_(FP)=1.6μm,T_(FP)=0.3μm,N_(D)=1×10^(16)cm^(-3)的条件下可达到840 V。研究进一步表明:通过优化器件结构,其场板效应可延伸至阳极下方的耗尽区,有效减缓了阳极边角处的电流拥挤。In order to improve the breakdown voltage of the Schottky barrier diode(SBD),a GaN-based SBD with a field plate(FP)structure has been systematically studied.Based on the Silvaco TCAD software,and by the method of controlling variables,that is,in some conditions of the different field plate length(L_(FP)),insulating layer thickness(T_(FP)),and the doping concentration(N_(D))in the GaN drift region,the differences of the device breakdown voltage(BV)have been simulated.Also,the change trend of the BV has been confirmed by the surface electric field distribution of the device.The results are the followings:When T_(FP)=0.3μm,N_(D)=1×10^(16)cm^(-3),and L_(FP)increases from 0 to 2.0μm,the BV of SBD has gradually increased and reached the threshold when L_(FP)=1.6μm.When L_(FP)=1.6μm,N_(D)=1×10^(16)cm^(-3),and the change of T_(FP)from 0.1μm to 0.4μm,the BV has firstly increased and then decreased,and reached the maximum value when T_(FP)=0.3μm.When L_(FP)=1.6μm,T_(FP)=0.3μm,and N_(D)increases from 1×10^(16)cm^(-3)to 1×10^(19)cm^(-3),the BV has only gradually decreased.Compared with the traditional field-free GaN-SBD,the BV of the designed terminal field-plate GaN-SBD can reach 840 V with the conditions of L_(FP)=1.6μm,T_(FP)=0.3μm,N_(D)=1×10^(16)cm^(-3).It is further confirmed that the proposed FP can extend to the depletion region under the anode,resulting in alleviating the current crowding around the anode corner.

关 键 词：场板结构 氮化镓 肖特基势垒二极管 击穿电压 

分 类 号：TN304.2[电子电信—物理电子学]