Method for lapping semiconductor material

摘要

It has been discovered that plastic deformation of a wafer of light-emitting semiconductor material during processing creates areas of poor radiative efficiency known as large dark spot (LDS) defects. An improved technique for lapping is described which alleviates stress and substantially reduces the initiation and propagation of such defects. Conventionally, wafers are affixed to a mounting plate by coating the plate with wax or some other appropriate adhesive and then applying pressure. The improvement comprises interposing a spacer between the mounting plate and the wafer. The spacer is capable of accommodating surface irregularities and particulates while maintaining substrate planarity.