JPS6442127A - Pattern for alignment - Google Patents

Abstract

PURPOSE:To realize a high-accuracy alignment operation without being influenced by a change in an optical length such as a change is a stepped depth due to a wafer process or the like by a method wherein the intensity of an interference beam by a diffraction beam only from flat parts of a repetitive pattern which have been formed at prescribed intervals is used for the alignment operation. CONSTITUTION:One part of recessed parts and protruding parts is shaped to be flat and the other part is shaped to be not flat. That is to say, flat parts 2 generating a diffraction beam are formed at prescribed intervals for a pattern for alignment use; parts sandwiched between the individual flat parts 2 are formed in non-flat faces; by this setup, only the diffraction beam 5 from the flat parts 2 can be converged and captured. As a result, this operation is not affected by a thickness of a transparent film formed by a wafer process and a resist; the interference of the diffraction beam can be discussed only by referring to the intervals; the intensity of a signal for detection use is not lowered due to the process. By this setup, it is possible to always form an alignment pattern capable of obtaining the high intensity of the signal without depending on the wafer process and to enhance the accuracy of a pattern alignment operation.