Delta-doped \b{eta}-Ga2O3 Films With Low FWHM Charge Profile Grown By Metalorganic Vapor-Phase Epitaxy

TL;DR

This paper demonstrates the growth of low FWHM delta-doped ta-Ga2O3 films via MOVPE, highlighting the impact of growth temperature on surface segregation and charge profile sharpness, with promising implications for high-performance devices.

Contribution

It introduces a method to grow ta-Ga2O3 delta-doped films with low FWHM using MOVPE and analyzes how growth temperature affects surface segregation and doping profile quality.

Findings

Lower growth temperature reduces surface segregation coefficient.

Films grown at 600°C exhibit high electron concentration and low FWHM.

High-resolution microscopy shows no significant crystal degradation.

Abstract

We report on low-temperature MOVPE growth of silicon delta-doped \b{eta}-Ga2O3 films with low FWHM. The as-grown films are characterized using Secondary-ion mass spectroscopy, Capacitance-Voltage and Hall techniques. SIMS measurements show that surface segregation is the chief cause of large FWHM in MOVPE-grown films. The surface segregation coefficient (R) is observed to reduce with reduction in the growth temperature. Films grown at 600 {\deg}C show an electron concentration of 9.7 x 1012 cm-2 and a FWHM of 3.2 nm. High resolution scanning/transmission electron microscopy of the epitaxial film did not reveal any significant observable degradation in crystal quality of the delta sheet and surrounding regions. Hall measurements of delta-doped film on Fe-doped substrate showed a sheet charge density of 6.1 x 1012 cm-2 and carrier mobility of 83 cm2/V. s. Realization of sharp delta doping profiles in MOVPE-grown \b{eta}-Ga2O3 is promising for high performance device applications.