Growth of silicon-doped Al0.6Ga0.4N with low carbon concentration at high growth rate using high-flow-rate metal organic vapor phase epitaxy reactor

Abstract

The relationship between the carbon concentration and electrical characteristics of silicon-doped AlGaN (Al > 0.5) was investigated using a high-flow-rate metal organic vapor phase epitaxy (MOVPE) reactor. The carbon concentration and electrical properties of AlGaN (Al > 0.5) were measured as a function of the growth rate, V/III ratio, and growth temperature. The growth rate of Al0.6Ga0.4N was linearly controlled up to 7.2 µm/h under a constant ammonia (NH3) flow rate. However, a decrease in V/III ratio resulted in an increase in carbon concentration to 8 × 1017 cm−3. With increased growth temperature, the carbon concentration decreased to less than 2 × 1017 cm−3 without showing any reduction in growth rate. As a result, n-type Al0.6Ga0.4N with a carrier concentration of 5.4 × 1018 cm−3 and a resistivity of 2.2 × 10−2 Ω·cm was obtained.