Abstract: The susceptor according to the present invention comprises a main body in the shape of a trapezoidal plate, and which has three circular depressions formed in its surface. The main body is made of silicon carbide having a bulk density of 3.00 g/cm.sup.3 or more. At least 70% of the surface region of the main body is made of crystal particles having a diameter of 5 .mu.m or more. The main body has a thickness of, for example, 700 .mu.m. Six susceptors are attached to a hexagonal upper plate which is fastened to a shaft, and also to a hexagonal lower plate, thereby forming a barrel. Silicon wafers are placed in the circular depressions, so that single-crystal layers may be epitaxially formed on the wafers.

Abstract: A ceramic membrane device for a photomask is a ring-shaped base plate constituting a circumferential frame and having a flat front surface, an outer side surface and a rear surface, a front CVD coating supported on the front surface of the base plate and defining a flat surface on which a masking pattern is to be formed, and a rear CVD coating formed on the rear surface of the base plate. The front and rear CVD coatings are made of a silicon compound.

Abstract: A susceptor for use in a vertical vapor growth apparatus includes a susceptor body (12) having an upper surface, a plurality of wafer receiving portions (17) formed in the upper surface of the susceptor body (12), and plates (16) fixed in the upper surface of the susceptor body (12) near the wafer setting portions (17). The plates (16) have an upper surface such that, when wafers (5) are mounted in the wafer setting portions (17), the upper surfaces of the plates (16) and the wafers (5) are positioned substantially in the same plane. The plates (16) are made of quartz glass or fused silica.