High electron density $β-(Al_{0.18}Ga_{0.82})_2O_3/Ga_2O_3$ modulation doping using ultra-thin (1 nm) spacer layer

Nidhin Kurian Kalarickal; Zhanbo Xia; Joe Mcglone; Yumo Liu; Wyatt Moore; Aaron Arehart; Steve Ringel; Siddharth Rajan

paper

High electron density $β - (A l_{0.18} G a_{0.82})_{2} O_{3} / G a_{2} O_{3}$ modulation doping using ultra-thin (1 nm) spacer layer

arXiv:1910.11521

Abstract

We report on the design and demonstration of $β - (A l_{0.18} G a_{0.82})_{2} O_{3} / G a_{2} O_{3}$ modulation doped heterostructures to achieve high sheet charge density. The use of a thin spacer layer between the Si delta-doping and heterojunction interface was investigated in $β - (A l_{0.18} G a_{0.82})_{2} O_{3} / G a_{2} O_{3}$ modulation doped structures. We find that that this strategy enables higher 2DEG sheet charge density up to 6.1x10^12 cm^2 with mobility of 147 cm^2/Vs. The presence of a degenerate 2DEG channel was confirmed by the measurement of low temperature effective mobility of 378 cm^2/V-s and a lack of carrier freeze out from low temperature capacitance voltage measurements. The electron density of 6.1x10^12 cm^2 is the highest reported sheet charge density obtained without parallel conduction channels in an $(A l_{0.18} G a_{0.82})_{2} O_{3} / G a_{2} O_{3}$ heterostructure system.

High electron density β−(Al0.18​Ga0.82​)2​O3​/Ga2​O3​ modulation doping using ultra-thin (1 nm) spacer layer

Abstract

High electron density $β - (A l_{0.18} G a_{0.82})_{2} O_{3} / G a_{2} O_{3}$ modulation doping using ultra-thin (1 nm) spacer layer