An investigation was made of the structure of epilayers that had been grown, by means of molecular beam epitaxy, onto (001)GaAs substrates with various tilt angles and tilt directions. The epilayers were studied using X-ray diffraction, transmission electron microscopy, and etch pit density analysis. It was found that tilting the (001)GaAs substrate towards [010] was very effective in reducing the surface defect density of the ZnSe layers. Tilting it towards the [110] direction had no effect. An increasingly 2-dimensional nature of the initial growth mode was observed in the case of (001)GaAs substrates that were tilted towards [010]. The growth of a 1.8-thick ZnSe layer, on a (001)GaAs substrate which was tilted by 4 towards [010], resulted in a surface defect density of 104/cm2. It was noted that such a low density had rarely been obtained in ZnSe; without using a GaAs buffer layer.

J.S.Kim, S.H.Suh, C.H.Kim, S.J.Chung: Journal of Applied Physics, 1997, 81[9], 6107-11