DocumentCode :
1518600
Title :
Scaled Self-Aligned N-Polar GaN/AlGaN MIS-HEMTs With 
of 275 GHz
Author :
Nidhi ; Dasgupta, Sansaptak ; Lu, Jing ; Speck, James S. ; Mishra, Umesh K.
Author_Institution :
Dept. of Electr. & Comput., Univ. of California, Santa Barbara, CA, USA
Volume :
33
Issue :
7
fYear :
2012
fDate :
7/1/2012 12:00:00 AM
Firstpage :
961
Lastpage :
963
Abstract :
In this letter, we demonstrate state-of-the-art performance from N-polar GaN/AlGaN metal-insulator-semiconductor high-electron-mobility transistors. Self-aligned gate-first process was used for the fabrication of transistors. Graded InGaN and InN contact layers were used to achieve low ohmic contact resistance. The GaN channel thickness was scaled to 7 nm from previous generation of N-polar GaN devices to improve the aspect ratio and hence achieve better small-signal performance. The devices reported fT of 210 GHz for LG = 30 nm. To further improve the device performance, SiN sidewall spacers were etched and replaced with air gaps resulting in further boost in fT to a state-of-the-art value of 275 GHz.
Keywords :
MIS devices; air gaps; aluminium compounds; contact resistance; gallium compounds; high electron mobility transistors; indium compounds; ohmic contacts; silicon compounds; GaN-AlGaN; InGaN; SiN; air gaps; frequency 210 GHz; frequency 275 GHz; graded contact layers; low ohmic contact resistance; metal-insulator-semiconductor high-electron-mobility transistors; scaled self-aligned N-polar MIS-HEMT; self-aligned gate-first process; sidewall spacers; size 30 nm; size 7 nm; small-signal performance; Aluminum gallium nitride; Dielectrics; Gallium nitride; Logic gates; Performance evaluation; Resistance; Silicon compounds; 275 GHz; Contact regrowth; GaN scaling; InGaN contact; InN contact; N-polar GaN; self-aligned HEMT;
fLanguage :
English
Journal_Title :
Electron Device Letters, IEEE
Publisher :
ieee
ISSN :
0741-3106
Type :
jour
DOI :
10.1109/LED.2012.2194130
Filename :
6202323
Link To Document :
