Characterization of GaxIn1−xAs grown with TMIn

Abstract

High quality GaxIn1−xAs, lattice matched to InP, has been reproducibly grown by organometallic vapor phase epitaxy using trimethylgallium (TMGa), trimethylindium (TMIn), and AsH3 in an atmospheric pressure reactor with no observable adduct formation. For the first time, using TMIn, room temperature electron mobilities of 104 cm2/Vs and 77 K mobilities greater than 4 × 104 cm2/Vs have beep obtained. Residual donor doping densities in the low 1015 cm−3 range have been routinely obtained. Material with excellent morphology has been grown from 540 to 670 C with the highest quality material being obtained near 650 C. The 4 K photoluminescence (PL) peak due to carbon is not seen in the material grown at higher temperatures; however, it increases dramatically as the growth temperature is lowered. This increased carbon incorporation leads to a sharp drop in the electron mobility, which exhibits a T−0.5 behavior between 77 and 300 K. With optimum growth conditions, 4 K PL halfwidths of 4–5 meV are commonly observed. This high quality material is characterized by x-ray diffraction, PL, and Hall mobility measurements. Carbon and other impurity incorporation as a function of the growth parameters will be described.