关键词: 超高温硅外延, 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 on Si epitaxial wafers for 200 mm diameter BCD devices are studied, and the process control method of slip lines under ultra-high temperature conditions is explored. Based on the characteristics requirements of Si epitaxial wafers for BCD devices, the influence of graphite substrate position, substrate resistivity distribution, and temperature distribution on the slip lines of epitaxial layers under ultra-high temperature conditions is analyzed, and the epitaxial control method is optimized. Si epitaxial wafers for BCD devices are prepared using atmospheric pressure high-temperature chemical vapor deposition technology, and epitaxial wafers are tested and analyzed through equipment such as Hg-CV. Experimental results have shown that this process control method can effectively suppress the generation of slip lines while meeting the control requirements for epitaxial layer uniformity and pattern drift distortion required for BCD device processes. The stability of the process has been confirmed through long-term epitaxial verification.

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