Polyimide passivated AlGaN-GaN HFETs with 7.65 W/mm at 18 GHz |
| |
Authors: | Hampson M.D. Shyh-Chiang Shen Schwindt R.S. Price R.K. Chowdhury U. Wong M.M. Ting Gang Zhu Dongwon Yoo Dupuis R.D. Milton Feng |
| |
Affiliation: | Dept. of Electr. & Comput. Eng., Univ. of Illinois, Urbana, IL, USA; |
| |
Abstract: | Current metal-organic chemical vapor deposition-grown AlGaN-GaN heterojunction field-effect transistor devices suffer from threading dislocations and surface states that form traps, degrading RF performance. A passivation scheme utilizing a polyimide film as the passivating layer was developed to reduce the number of surface states and minimize RF dispersion. Continuous-wave power measurements were taken at 18 GHz on two-finger 0.23-/spl mu/m devices with 2/spl times/75 /spl mu/m total gate width before and after passivation yielding an increase from 2.14 W/mm to 4.02 W/mm in power density, and 12.5% to 24.47% in power added efficiency. Additionally, a 2/spl times/25 /spl mu/m device yielded a peak power density of 7.65 W/mm at 18 GHz. This data suggests that polyimide can be an effective passivation film for reducing surface states. |
| |
Keywords: | |
|
|