Abstract: A method of cleaning the process tube of the CVD apparatus comprising carrying silicon wafers out of the process tube, making temperature in the process tube lower enough than the process temperature, that is, equal to or higher than room temperature, and supplying cleaning gas, in which ClF.sub.3 is contained, into the process tube to react with poly-silicon and amorphous silicon (Si) stuck to that portion of the inner wall of the process tube which is not in the uniformly-heated zone in the process tube, whereby the matters stuck can be removed from the inner wall of the process tube for a shorter time.

Abstract: This invention relates to a method for forming a boron-containing film of high quality on the surfaces of semiconductor wafers by CVD or epitaxial techniques using reaction gases including at least boron trifluoride.

Abstract: An ion implantation device which is characterized in that source gas is supplied to an ion source from a gas cylinder provided in an external portion of the ion implantation device to maintain the cleanness of the clean room by reducing the frequency of exchanging gas cylinder for new one.

Abstract: A heat-treating method and apparatus are disclosed which are employed for the manufacture of, for example, a semiconductor device. A substrate to be treated is set in a floating state with an air space defined relative to an underlying opposite surface. A ring-like temperature security member is located with a small gap left relative to an outer periphery of the substrate. The heating of the substrate is achieved in this state. Infrared lamps are selected as a heating source and the surface underlying the substrate provides a reflection surface. The rear surface of the substrate is heated by reflection light travelling across the aforementioned air space. A heat dissipation from the marginal edge portion of the substrate is prevented by the temperature security member to obtain uniformity of heat over the whole area of the substrate. The presence of the air space ensures the ready loading and unloading of the substrate and hence the ready operability.