关键词: 超高温外延, 高阻薄层, 滑移线, 热应力, 电阻率分布, 温度分布控制

Abstract: The influencing factors of slip lines of silicon epitaxial wafers with a diameter of 200 mm for BCD devices were studied in detail. The process control methods for slip lines under ultra-high temperature condition were further explored. Based on the requirements of silicon epitaxial wafers for BCD devices, the article analyzes the influence of graphite-susceptor position, substrate resistivity distribution, and temperature distribution on the slip lines under ultra-high temperature condition, and optimizes the control method. The silicon epitaxial wafers were prepared by APHT-CVD technology. The properties of epitaxial layer were evaluated by Hg-CV, FTIR, SP1, 4PP and SRP. Slip lines were effectively controlled. The uniformity of epitaxial layer and the shift and distortion of the pattern were fully optimized. The process stability was extremely proved by long-term epitaxial monitoring.

Key words: ultra-high temperature silicon epitaxy, high resistivity and thin layer, slip lines, thermal stress, resistivity distribution, temperature distribution control