IDENTIFICATION OF CRYSTAL ORIENTATION AND MECHANISM DEVICE FORMED USING THE IDENTIFICATION

摘要

PURPOSE:To precisely conform the direction of a photomask pattern to be transferred on a film to a crystal orientation by a method wherein the crystal orientation is identified using two or more of the same etching patterns. CONSTITUTION:Circular oxide film removal parts 3 are reliably formed on a thermal oxide film 2 on an Si wafer 1 and the wafer 1 under the removal parts 3 is subjected to anisotropic etching to form quadrangular pyramid-shaped hole patterns 7. A parallel ruling in the visual field of an optical microscope is used and two sides of each pattern 7 are superposed on the parallel ruling. That is, two pieces of the patterns 7 arranged on a straight line are selected and a crystal axis direction <110> is identified. Two pieces of these patterns 7 are aligned with an alignment pattern 9 of a photomask 8, a photomask pattern 12 is transferred on the film 2 and an anisotropic etching is performed. As a result, alignment of a very good accuracy that the alignment deviation of the photomask pattern 12 from a crystal orientation is + or -0.05 deg. or less can be attained.