高均匀性150mm 4H-SiC外延生长

High Uniformity 150mm 4H-SiC Epitaxial Growth

本文采用单片热壁反应炉在偏4°斜切150mm 4H-SiC衬底上进行同质外延生长。首先,通过不引入基座旋转进行外延生长,分别测量出水平和垂直于气流方向上外延厚度和浓度分布,确认了生长源和N型掺杂源在晶片上的耗尽方式。其次,通过引入基座旋转进行外延生长,分别测量出外延层厚度和浓度的分布情况。最后,通过调整载气比例来改善外延层厚度分布,所得6英寸的4H-SiC外延层厚度均匀性为0.30%(sigma/mean),通过优化掺杂源分配等方式来改善浓度均匀性,所得外延层浓度均匀性为4.52%(sigma/mean),该结果为大尺寸4H-SiC外延批量性生产奠定了基础。

Homo-epitaxial growth of 4H-SiC has been carried out on 4°off-axis 150 mm diameter substrates in a hot wall reactor.Based on the un-rotated situation,the deposition curves of process gas and doped-gas have been confirmed via the epitaxial thickness and concentration distribution.Then,the epitaxial growth is carried out by introducing support disc rotation,and the thickness and concentration distribution of epitaxial layer were measured,respectively.Finally,the thickness and concentration distribution of epitaxial layer were improved by adjusting the carrier gas ratio and optimizing the doping source distribution respectively.Based on our modified 150 mm 4H-SiC epitaxial growth process,excellent thickness and doping uniformities(sigma/mean)of 0.30%and 4.52%have been achieved.These results lay a foundation for mass production of large-scale 4H SiC epitaxy.