PURPOSE: To enhance a visible light permeability by raising a temperature of an Si substrate to a special temperature or higher in the case of manufacturing an X-ray mask formed of a membrane made of an SiN film on the substrate by using a reduced pressure CVD (Chemical Vapor Deposition) method.
CONSTITUTION: In order to form an SiN film on an Si substrate by an LPCVD device to be used for manufacturing an X-ray mask membrane, a cleaned Si substrate 16 is set to a quartz boat 14, and inserted into a quartz tube 10 by a quartz boat elevation mechanism. Then, the substrate is heated to 1000°C or higher by a heater 12, reaction gas (SiH2Cl2+NH3) in which a flow rate ratio of SiH2Cl2 gas to NH3 gas is set to 2 and carrier gas (N2) are introduced from a gas inlet 18 to form an SiN film. When it becomes a predetermined thickness, the gases are shut OFF, the substrate temperature is lowered to the ambient temperature, and the substrate is removed. Thus, the SiN film having high visible light permeability is obtained, and an aligning accuracy of the mask to a wafer can be enhanced by using the X-ray mask.
RAKESHIYU KUMAARU
YAMASHITA YOSHIO
