Device for semiconductor production and method for semiconductor production

A treatment is carried out by using chemical vapour deposition (chemical vapour-phase deposition) on a main treatment surface (14) of a semiconductor substrate (8) under conditions such that the semiconductor substrate (8) is held on a base surface of a stage (10) by a suction force, which is produced by reducing the pressure in a vacuum bag (13). In the case of such a treatment, inert gas is supplied by an inert-gas feed mechanism (24) through a liquid line (43) and inert-gas feed holes (42) to an inert-gas flushing aperture (32) constituted by an intermediate space between an outermost circular surface (31) of an outer section of a substrate-holding surface (11) and a rear main surface (12) of the semiconductor substrate (8). The inert gas flow through inert-gas flushing aperture (32) into a reaction chamber (6). The flow of inert gas prevents undesired objects or reaction byproducts (34) from easily entering into an internal region of the substrate-holding surface (11). This prevents deposition of the reaction byproducts and avoids reduction of the holding strength of the semiconductor substrate by the suction force. As a result, the operating efficiency of a semiconductor-production device and the production yield can be improved.