Abstract: A susceptor 1 for a gas phase growth apparatus to which a round depressed pocket 2 with a bottom a side wall is formed for the placing of a semiconductor wafer 3 wherein a protuberance 6 is provided on the circumference of the pocket at and near the position ere said semiconductor wafer touches said side wall 4 of the pocket 2 in such a way that the protuberance 6 covers a part of a chamfered area of said semiconductor wafer 3 without touching it. Thus cracks and breakage due to adhesion between a susceptor and a wafer may be prevented.

Abstract: A cylindrical apparatus for the growth of epitaxial layers having disposed inside a bell jar a susceptor provided thereon with pockets for retaining a substrate is disclosed. It allows the flow rate of a raw material gas inside the apparatus to be uniformized, the fluctuation of film thickness of epitaxial layers within one batch to be repressed below 5%, and the fluctuation of film thickness of an epitaxial layer in the substrate to be decreased by equalizing the gap area between the peripheral surface of the susceptor and the internal wall surface of the bell jar at least in the lateral wall portions of the bell jar confronting the substrates on the susceptor.