Research on Back-Sealed Technology and Its Application in Mass Production of High Resistivity and Thick Epitaxy on Heavily-Doped Substrates

In this work, the influence of self-doping during epitaxy was discussed, and a back-sealed technology was introduced to fabricate the thick P-type epitaxial films of high resistivity by controlling the self-doping from the heavily-doped P-type substrates with resistivity less than 0.02Omegacm on PE-2061S. Based on investigation of the processing parameters of epitaxial growth, a simplified model describing self-doping was established. By optimizing the processing parameters, high-quality epitaxial layers with high resistivity and thickness have been developed. The epitaxial layers´ resistivity is controlled within 65Omegacmplusmn5Omegacm, while the thickness is controlled within 65 mumplusmn5 mum. For the production of more than 40,000 pieces of wafer per month, the rate of finished product is higher than 98%. Market applications have demonstrated that the epitaxial wafers can meet the requirements for research and production of advanced electronic devices as well