Thin plate holder

Abstract

Abstract PURPOSE:To reduce probability of pinching in a foreign material or photoresist between a thin plate and a holder and to enhance yield of manufactured goods by a method wherein the shape of the surface of the holder is formed so as not to come in contact with the wafer with the whole of the surface of the thin plate and as to come in contact with the wafer dispersedly. CONSTITUTION:The wafer 4 is sucked with a vacuum by the surface of the wafer holder 7 through a hole 15 connected to a vaccum source, grooves 14 in checkerboard pattern are formed as to unify sucking forces at respective parts, and plural projections 16 are provided at an equal interval. The area of the flat parts of the projections 16 to come in contact with the wafer 4 is made as about 3% of the whole of area of the wafer being reduced sharply as compared with 70-80% of the customary wafer holder. Moreover to eliminate influence of the photo resist 5 coming around into the back of the wafer 4, chamfering is provided at the circumferential part to make the wafer 4 so as not to come in contact with the wafer holder 7. Accordingly the probability of pinching in the foreign material 6 or the photo resist 5 between the thin plate and the thin plate holder is reduced.

Inventors

• 👤 Susumu Aiuchi
• 👤 Mineo Nomoto
• 👤 Yukio Kenbo
• 👤 Yasuo Nakagawa
• 👤 Nobuyuki Akiyama

Bibliographic Details