PSEUDOMORPHIC HIGH-ELECTRON-MOBILITY HETEROSTRUCTURES WITH EXTREMELY HIGH-CONDUCTIVITY USING TE AS N-TYPE DOPANT BY LOW-PRESSURE METAL-ORGANIC CHEMICAL-VAPOR-DEPOSITION

Modulation-doped AlxGa1-xAs/InyGa1-yAs/GaAs single-quantum-well struct ures have been grown by low-pressure metal organic vapor phase epitaxy and characterized by Hall, C-V measurements, and photoluminescence sp ectroscopy. The use of tellurium instead of silicon as an n-type dopan t for A1(x)Ga(1-x)As increases the electron concentration without decr easing the electron mobility. High free-electron concentrations of n(s )=7.5X10(12) cm(-2) (300 K) and n(s)=3.7X10(12) cm(-2) (77 K), and Hal l mobilities of mu=5470 cm(2) (Vs)(-1) (300 K) and mu=24 600 cm(2) (V s)(-1) (77 K) were obtained. The high concentration and mobility produ ct of the channel: n(s) mu=4.1 X 10(16) (V s)(-1) at 300 K and n(s) mu =9.1 X 10(16) (V s)(-1) at 77 K, makes it a preferred choice for high- speed applications.