栅极几何结构对MIS栅结构常关p-GaN/AlGaN/GaN HEMTs性能的影响  

Influence of Gate Geometry on Normally-off p-GaN/AlGaN/GaN HEMTs Characteristics with MIS Gate Structure

作　　者：都继瑶 DU Jiyao(Shenyang Ligong University,Shenyang 110159,China;Shenyang Ligong University Technology Development Corporation,Shenyang 110013,China)

机构地区：[1]沈阳理工大学自动化与电气工程学院,沈阳110159 [2]沈阳理工大学科技开发总公司,沈阳110013

出　　处：《沈阳理工大学学报》2025年第1期72-77,共6页Journal of Shenyang Ligong University

基　　金：辽宁省教育厅高等学校基本科研项目(JYTQN2023044);辽宁省属本科高校基本科研业务费专项资金资助项目。

摘　　要：高电子迁移率晶体管(high electron mobility transistors,HEMTs)具有高速开关和极高击穿电场等特性,在功率器件领域应用广泛。为提高HEMT器件性能,通过实验研究了栅极几何结构对具有金属/绝缘体/半导体(MIS)栅极结构的常关型p-GaN/AlGaN/GaN HEMTs性能的影响。栅极介质层采用5 nm厚的原位生长AlN,AlN/p-GaN界面呈现出更明显的能带弯曲和更宽的耗尽区,有利于阈值电压向正向偏移,且其相对较宽的能带错位有助于抑制栅极电流。实验结果表明:与栅极非覆盖区长度为0μm和6μm的MIS栅极相比,非覆盖区长度为3μm的MIS栅极可提高器件综合性能,有效抑制正向栅极电流,将阈值电压提高至3 V,并较好地保持电流密度为46 mA/mm;栅极结构中两侧没有栅极覆盖的区域在导通过程和导通状态下均可引起较大的沟道电阻,且沟道电阻随着非覆盖区长度增加而上升。High electron mobility transistors(HEMTs)are characterized by high-speed switching and exceptionally high disruptive electric field,which renders them widely used in the field of power devices.To enhance the performance of HEMT devices,the influences of gate geometry on normally-off p-GaN/AlGaN/GaN HEMTs with MIS(metal/insulator/semiconductor)gate structure are investigated,in which an in-situ grown AlN layer of 5 nm is utilized as gate insulator.The AlN/p-GaN interface presents a more obvious energy band bending and a wider depletion region,which helps to positively shift the threshold voltage.In addition,the relatively large conduction band offset of AlN/p-GaN is beneficial for suppressing the gate leakage current.It is demonstrated that compared with the MIS gates with 0 and 6μm gate uncovered region,a MIS gate with 3μm gate uncovered region could achieve a great comprehensive device performance,including effectively suppressing the forward gate leakage current,shifting the threshold voltage to 3 V and keeping a decent current density of 46 mA/mm simultaneously.Moreover,the uncovered region without gate electrode covering at both sides in gate structure induces a large channel resistance at turning-on process and on-state.Further,the channel resistance would rise by increasing the length of uncovered region.

关 键 词：p-GaN/AlGaN/GaN异质结 AlN介质层 常关型器件 金属/绝缘体/半导体 栅极非覆盖区 

分 类 号：TN323.6[电子电信—物理电子学]