Effect of As4/Ga flux ratio on electrical properties of NID GaAs layers grown by MBE

Abstract

The effect of the As4/Ga flux ratio R on NID GaAs layers has been studied when the MBE growth chamber is used without baking after reloading the arsenic cells, in order to increase the productivity of the system. In these conditions a change from p- to n-type is observed when R is varied from 1.8 to 14. Satisfactory p-type material is obtained at R ≤ 3 (p = 2.0 × 1014 cm−3, μ77 K = 6200 cm2 V−1 s−1). The maximum n-type mobility occurs at R = 5.8. Photoluminescence spectroscopy confirms the effect of R on the incorporation of residual impurities.