APPARATUS AND METHOD FOR TEXTURE ANALYSIS ON SEMICONDUCTOR WAFERS

An apparatus and method for performing rapid, high-resolution polycrystalline crystallographic texture analysis, by calculating an Orientation Distribution Function (ODF) from partial pole figures obtained from x-ray diffraction measurements on large samples, e.g., 200 millimeter diameter wafers. The measurement apparatus includes a 2-D area x-ray detector and a collimated x-ray source arranged in a specific, fixed spatial relationship dependant on the properties of the sample to be measured, and also includes a particular wafer motion assembly. The wafer motion assembly includes three mutually orthogonal rectilinear translation stages, and a .phi. rotation stage mounted thereon, as an uppermost motion stage, with its range restricted to 180.degree. of rotation. .theta.-2.theta. and .chi. motions are eliminated, and the close deployment of the x-ray source and area detector to the measuring spot on the wafer is such that the detector covers a sufficient range of 2.theta. and .chi. to capture multiple diffraction arcs in each frame. The invention employs a new and advantageous texture analysis protocol to determine ODF from the severely truncated pole figures thus obtained, through comparison of experimental ODF figures with calculated ones. The resulting system is fast, accurate, amenable to automation, and does not require highly skilled personnel to operate.