WAFER HOLDING DEVICE

摘要

PURPOSE:To inhibit the outflow of gas through the peripheral edges of a wafer and to prevent the peripheral environment of the wafer from being contaminated due to a scattering of dust by a method wherein sidewalls, on which the outer peripheries of the end surfaces of the wafer are abutted, are provided around a holding plate and a gas lead-out port and gas introducing ports are respectively formed in the almost central part of the holding plate and in the peripheral parts of the plate. CONSTITUTION:Sidewalls 4, on which the outer peripheries of the end surfaces of a wafer 6 are abutted, are provided around a holding plate 1 and at the same time, gas introducing ports 9 are respectively form in the vicinities of the sidewalls 4 and a gas lead-out port 8 is formed in the almost central part of the plate 1. Accordingly, a cavity part 7 is formed between the wafer 6 and the plate 1 in a state that the outer peripheries of the end surfaces of the wafer 6 are respectively abutted on the end surfaces 5 of the sidewalls 4, gas made to blow off through the ports 9 is reduced its breakthrough through the cavity part 7 to the minimum, goes toward the center of the plate 1 while proceeding along the surface of the wafer 6, is made to flow while a wafer holding force is generated, is collected in the port 8 and goes out to the outside through the port 8. Thereby, the outflow of the gas through the peripheral edges of the wafer can be inhibited and the contamination of the peripheral environment of the wafer due to a scattering of dust is prevented.