Multiple-step annealing for 50% enhanced p-conductivity of GaN

Abstract

In this article, multiple-step rapid thermal annealing (RTA) processes for the activation of Mg doped GaN are compared with conventional single-step RTA processes. The investigated multiple-step processes consist of a low temperature annealing step at temperatures between 350°C and 700°C with dwell times up to 5 min and a short time high temperature step. With optimized process parameters, and multiple-step processes, we achieved p-type free carrier concentrations up to 1–2×10 18 cm −3. The best achieved conductivity, so far, lies at 1.2 Ω −1 cm −1. This is a 50% improvement compared to conventional single-step process at 800°C, 10 min.