Abstract: This invention concerns a production method and a processing apparatus for semiconductor devices, as well as an evacuating apparatus used for the processing apparatus. According to this invention, since the evacuation system of pressure-reduction processing apparatus for conducting various wafer processings during production steps of semiconductor devices is constituted only with oil-free vacuum pump, deleterious oil contaminations or carbonation products of oils produced from oils upon heating are not present in the pressure-reducing processing chamber as compared with conventional pressure-reducing processing apparatus using a vacuum oil pump as an evacuation pump and the production method of semiconductor devices using such apparatus.

Abstract: A vacuum pump with a heating portion for preventing adhesion of reaction products on a discharge side thereof.

Abstract: This invention concerns a production method and a processing apparatus for semiconductor devices, as well as an evacuating apparatus used for the processing apparatus. According to this invention, since the evacuation system of pressure-reduction processing apparatus for conducting various wafer processings during production steps of semi-conductor devices is constituted only with oil-free vacuum pump, deleterious oil contaminations or carbonation products of oils produced from oils upon heating are not present in the pressure-reducing processing chamber as compared with conventional pressure-reducing processing apparatus using a vacuum oil pump as an evacuation pump and the production method of semiconductor devices using such apparatus.

Abstract: A vaned diffuser disposed around an outer periphery of an impeller of a centrifugal compressor comprises a pair of diffuser plates which constitute side walls of the vaned diffuser and define therebetween a fluid channel, and a plurality of vanes arranged in the fluid channel defined between the diffuser plates. At least one rib is arranged on that surface area of at least one of the diffuser plates which is defined between the adjacent vanes, so as to improve condition of a fluid flowing through the vaned diffuser to thereby improve efficiency of the latter. The rib is of a height not larger than one-half the height of the vanes and has a leading edge located upstream of the leading edges of the vanes as viewed in a fluid flow direction.