Effects of post-annealing on the passivation interface characteristics of AlGaN/GaN high electron mobility transistors
Effects of post-annealing on the passivation interface characteristics of AlGaN/GaN high electron mobility transistors
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后退火对AlGaN/GaN高电子迁移率晶体管钝化界面特性的影响
DOI：
10.1016/j.mssp.2015.02.062
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Sam
中科院分区：
文献类型：
--
作者：
Yeo;Kyoung;Sam
我们结合对AlGaN/GaN高电子迁移率晶体管(HEMT)钝化界面缺陷的定量分析，研究了在成型气体环境中的后退火对电介质上自旋(SOD)缓冲钝化以及传统的等离子体增强化学气相沉积(PECVD)Si3N4钝化结构的影响。经C-V表征，PECVDSi3N4的界面态密度(DIT)比SODSiOx的界面态密度(DIT)高一个数量级(1012-1013 cm−2 eV−1)。PECVDSi3N4中的明显还原被提取到1011-1012 cm−2 eV−1能级，经后退火后傅里叶变换红外光谱的Si-N峰有较强的吸收。另一方面，从SODSiOx得到的Dit值差异可以忽略不计。本文提出，具有Si3N4钝化的AlGaN/GaN HEMT在退火前的测量能级较低(~156 mA/mm)，在退火后的最大漏电流密度显著恢复(~13%)，这是由于退火前的高密度和PECVDSi3N4在退火后的大幅度降低所致。经Si3N4钝化的HEMT栅漏漏电流(从~10−~3降至~10−~5A，栅宽100-μm)在退火后的显著降低也可能归因于Dit的降低。
We examined the effects of post-annealing in forming-gas ambient on the spin-on-dielectric (SOD)-buffered passivation as well as the conventional plasma-enhanced chemical vapor deposition (PECVD) Si3N4passivation structure in association with the quantitative analysis of defects at the passivation interfaces of AlGaN/GaN high electron mobility transistors (HEMTs). Before the annealing, the interface state densities (Dit) of the PECVD Si3N4are one-order higher (1012–1013cm−2eV−1) than those of the SOD SiOx(1011–1012cm−2eV−1) as derived fromC–Vcharacterization. Clear reduction inDitfrom the PECVD Si3N4is extracted to a level of 1011–1012cm−2eV−1with a stronger absorption from Si–N peak in Fourier transform infrared spectroscopy spectra after the post-annealing. On the other hand, negligible difference inDitvalue is obtained from the SOD SiOx. In this paper we propose that much lower measurement levels (~156 mA/mm) before the annealing and substantial recovery (~13% increase) after the annealing in maximum drain current density of the AlGaN/GaN HEMTs with Si3N4passivations are due to the original higher density before the annealing and greater reduction inDitof the PECVD Si3N4after the annealing. Significant reduction after the annealing in gate–drain leakage current (from ~10−3to ~10−5A, 100-μm gate width) of the HEMTs with the Si3N4passivation is also supposed to be attributed to the reduction ofDit.