JPS6423531A - Formation of die alignment mark - Google Patents

Abstract

PURPOSE:To prevent the detection accuracy during a detection operation of a mask position from deteriorating by a method wherein an intermediate layer which does not react with a semiconductor substrate and a die alignment mark is installed and a metal to be used as the alignment mark is formed on a recessed part formed on this intermediate layer so that the surface and an edge of the alignment mark are not roughened due to a heat treatment operation. CONSTITUTION:An intermediate layer 22 composed of SiO2 is grown on a GaAs semiconductor substrate 21; a first resist 23 is coated; a region to form die alignment mark is exposed and developed, after that, the intermediate layer 22 in an unnecessary part is removed by an etching operation. Then, the first resist 23 is removed by an organic cleaning operation; after that, a second resist 24 is coated; a die alignment mark pattern is formed on the intermediate layer 22 by an optical exposure operation; a development operation is executed. Furthermore, a position to form the alignment mark on the intermediate layer 22 is removed slightly by the etching operation; a recessed part 27 is formed. Then, metals 25 and 26 are evaporated. The second resist 24 and the metal 25 in an unnecessary part are removed by a lift-off method by the organic cleaning operation. By this setup, this can be utilized as the alignment mark whose surface is smooth and which has a uniform edge; after a heat treatment operation it is possible to prevent the position detection accuracy from deteriorating.