Realization of improved metallization-Ti/Al/Ti/W/Au ohmic contacts to n-GaN for high temperature application

被引：12

作者：

Motayed, A ^{[1
]}

Davydov, A ^{[1
]}

Boettinger, WJ ^{[1
]}

Josell, D ^{[1
]}

Shapiro, AJ ^{[1
]}

Levin, I ^{[1
]}

Zheleva, T ^{[1
]}

Harris, GL ^{[1
]}

机构：

[1] NIST, MSEL, Div Met, Gaithersburg, MD USA

来源：

Physica Status Solidi C - Conferences and Critical Reviews, Vol 2, No 7 | 2005年 / 2卷 / 07期

关键词：

D O I：

10.1002/pssc.200461604

中图分类号：

TQ174 [陶瓷工业]; TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

Tungsten metal layer was used for the first time as an effective diffusion barrier for the standard Ti/AVTi/Au ohmic metallization scheme to obtain thermally stable ohmic contact suitable for high temperature applications. Comparative studies were performed on three distinct metallization schemes: 1) standard GaN/Ti/AUTi/Au, 2) GaN/Ti/Al/W/Au, and 3) GaN/Ti/Al/Ti/W/Au. For the GaN with doping level of 5 x loll CM 3, the lowest specific contact resistance for the Ti/Al/Ti/W/Au metallization scheme annealed in argon at 750 degrees C for 30 see was 5 x 10(-6) Omega.cm(2), which is comparable to the standard Ti/Al/Ti/Au scheme. X-ray diffractions (XRD), auger electron spectroscopy (AES) depth profiling, field-emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), and cross-sectional transmission electron microscopy (TEM) revealed that the Ti/Al/Ti/W/Au metallization has superior morphology and microstructural properties compared to standard Ti/Al/Ti/Au metallizations. Remarkably, this metallization was able to withstand thermal aging at 500 degrees C for 50 hrs; with only marginal morphological and electrical deterioration. These studies revealed that the utilization of a compound diffusion barrier stack, as in the Ti/Al/Ti/W/Au metallization, yields electrically, structurally, and morphologically superior metallizations with exceptional thermal stability.

引用

页码：2536 / 2539

页数：4

共 6 条

[1] Very low resistance multilayer ohmic contact to n-GaN [J].