Patent ID: 6731373
Filing Date: 2004-05-04
Classification: G03F,H01L

Abstract:
A method for imprinting wafer-identifying information using a patterned resist layer, on wafers each having a plurality of thin-film devices formed thereon in a batch, the wafer-identifying information including a plurality of digits, each digit being expressed with a numeral or a symbol, the method comprising the steps of:selecting a wafer to be imprinted with the wafer-identifying information; forming a resist layer on the selected wafer; exposing the resist layer, using a mask, to light for forming a latent image of the wafer-identifying information; and forming the patterned resist layer by developing the exposed resist layer, wherein: in the step of exposing the resist layer, exposure is performed for each digit of the wafer-identifying information in which the numeral or the symbol is changeable wafer by wafer, by selecting a mask on which a pattern of a numeral or the symbol to be imprinted is drawn thereon for each digit; and in the step of exposing the resist layer, the selection of a mask on which the pattern of a numeral or the symbol to be imprinted is drawn thereon and the exposure using the selected mask are repeated as many times as the number of digits of the wafer-identifying information, so that exposure is performed for all digits of the wafer-identifying information.