Breakdown characteristics of deep-ultraviolet Al0.6Ga0.4N p-i-n avalanche photodiodes
Abstract
A top-illuminated deep-ultraviolet Al0.6Ga0.4N p-i-n avalanche photodiode (APD) structure was designed and grown by metalorganic chemical vapor deposition on an AlN bulk substrate and on two different quality AlN/sapphire templates, and APDs were fabricated and tested. The APD devices with a circular diameter of 20 μm have demonstrated a distinctive reverse-bias breakdown behavior. The reverse breakdown voltage of the APDs is approximately −140 V, which corresponds to a breakdown electric field of 6–6.2 MV/cm for the Al0.6Ga0.4N material as estimated by Silvaco TCAD simulation. The APDs grown on the AlN bulk substrate show the lowest leakage current density of <1 × 10−8 A/cm2 (at low reverse bias) compared to that of the devices grown on the AlN templates. From the photocurrent measurement, a maximum gain (current limited) of 1.2 × 104 is calculated. The average temperature coefficients of the breakdown voltage are negative for APD devices fabricated from both the AlN bulk substrate and the AlN templates, but these data show that the coefficient is the least negative for the APD devices grown on the low-dislocation-density AlN bulk substrate.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 09, 2022
- Source ID
- 10.1063/5.0073515
Entities
People
- Frank Mehnke
- Hoon Jeong
- Marzieh Bakhtiary-noodeh
- Minkyu Cho
- Nepomuk Otte
- Russell D. Dupuis
- Shyh-chiang Shen
- Theeradetch Detchprohm
- Zhiyu Xu
Organizations
- Army Research Office
- Georgia Tech
- National Science Foundation
- United States Department of Energy