Gallium Nitride–Based Heterostructures on Silicon Substrates for Powerful Microwave Transistors

Abstract

A unique method for forming gallium nitride–based heterostructures on silicon substrates at low growth temperatures (less than 950°C) is proposed and implemented. The formed heterostructure has an atomically smooth surface with a mean square roughness of 0.45 nm and high crystalline quality. The average layer resistance of the channel of a two-dimensional electron gas was 415 Ω/square at an electron concentration of 1.65 × 10¹³ cm^–2 and mobility 920 cm²/(V s). The maximum value of the drain saturation current for transistors with a gate width of 1.2 mm was 930 mA/mm, which corresponds to the best results worldwide for gallium nitride transistors on silicon substrates.