SURFACE TREATING METHOD FOR SEMICONDUCTOR SUBSTRATE

PURPOSE:To treat the whole surface of a semiconductor substrate uniformly by little HMDS by treating the surface of the semiconductor substrate by HMDS vapor formed by natural evaporation in an evaporator with an evaporation-area spreading member. CONSTITUTION:Hexamethyldisilazane (HMDS) vapor is formed by natural evaporation in an evaporator 3 with evaporation-area spreading members 8-10, which have a function, in which an HMDS liquid 5 is sucked up by a capillary phenomenon, and one parts of which are positioned in the HMDS liquids 5 and the other parts of which are positioned outside the HMDS liquids 5. The surface of a semiconductor substrate S is treated by HMDS vapor shaped in said evaporator 3. Nitrogen gas N2 flowing into a partitioning chamber 11a from an inlet port 4a for the evaporator 3 passes through clearances 12a-12c in succession and flows in each partitioning chamber 11a-11d, and includes a sufficient quantity of HMDS vapor and flows out to an HMDS vapor line 6 from an outlet port 4b. HMDS vapor flows into a reaction vessel 15 from an inlet port 15a, and the surface of the semiconductor substrate S is treated with HMDS vapor.