Investigation of zinc incorporation in GaAs epilayers grown by low-pressure metalorganic chemical-vapor deposition

Abstract

Low‐pressure metalorganic chemical‐vapor deposition was adopted to grow p‐type GaAs epilayers. Triethylgallium and arsine (AsH₃) are used as Ga and As sources, respectively. Diethylzinc (DEZn) is used as a p‐type dopant. The hole‐carrier concentration and zinc incorporation efficiency are studied by Hall measurements and 16‐K photoluminescence spectral. The influence of growth parameters, such as the DEZn mole fraction, growth temperature, and AsH₃ mole fraction, on the zinc incorporation and the epilayer growth rate are discussed. The hole‐carrier concentration increases with increasing DEZn and AsH₃ mole fractions and decreases with increasing growth temperature. A vacancy control model can be adopted to explain the above results consistently. The growth rate of the epilayer is enhanced by zinc incorporation and decreases with increasing growth temperature. The decrease in growth rate is presumably due to the decrease in diethylzinc incorporation at higher growth temperatures.