Simulation of zincblende AlGaN/GaN high electron mobility transistors for normally-off operation
Simulation of zincblende AlGaN/GaN high electron mobility transistors for normally-off operation
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DOI：
10.1088/1361-6463/aa74fc
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发表时间：
2017-06
期刊：
影响因子：
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通讯作者：
R. Grady;C. Bayram
中科院分区：
文献类型：
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作者：
R. Grady;C. Bayram
在这项工作中，我们研究了通过Synopsys Sentaurus Technology计算机辅助设计（TCAD）实现锌双晶石（ZB-）相AlXGa(1−X)N/GaN高电子迁移率晶体管（HEMTs）正常关闭工作的设计参数。由于zb - iii相氮化物是无极化的，AlXGa(1−X)N/GaN异质结处的二维电子气（2DEG）通道通过AlXGa(1−X)N势垒层的有意δ掺杂部分形成。各设计参数（即al含量和AlXGa(1−X)N势垒厚度）的影响；δ掺杂位置（AlXGa(1−X)N势垒内）、δ掺杂AlXGa(1−X)N层厚度及其掺杂量；对栅极金属进行了详细的研究，并给出了设计折衷方案。我们发现栅极金属的功函数对正常关断行为和导通电压有很大的影响。我们的研究结果表明，AlXGa(1−X)N势垒中al含量为35%或更少会导致正常关闭行为，而AlXGa(1−X)N势垒厚度可以有效控制导通电压。总体而言，我们提供了zb相AlGaN/GaN HEMT技术中控制正常开/关操作、阈值电压和2DEG密度的设计指南。
In this work we investigate design parameters enabling normally-off operation of zincblende (ZB-) phase AlXGa(1−X)N/GaN high electron mobility transistors (HEMTs) via Synopsys Sentaurus Technology Computer Aided Design (TCAD). As ZB-phase III-nitrides are polarization-free, the 2D electron gas (2DEG) channel at the AlXGa(1−X)N/GaN heterojunction is formed through intentional δ-doping part of the AlXGa(1−X)N barrier layer. The impact of each of the design parameters (i.e. Al-content and thickness of AlXGa(1−X)N barrier; δ-doping location (within the AlXGa(1−X)N barrier), δ-doped AlXGa(1−X)N layer thickness and its doping amount; gate metal) are studied in detail and design trade-offs are reported. We show that work function of the gate metal impacts normally-off behavior and turn-on voltage considerably. Our results suggest that Al-content of 35% or less in the AlXGa(1−X)N barrier results in a normally-off behavior whereas AlXGa(1−X)N barrier thickness is effective in controlling the turn-on voltage. Overall, we provide design guidelines in controlling the normally-on/-off operation, threshold voltage, and 2DEG density in ZB-phase AlGaN/GaN HEMT technology.