Method for cleaning back face of 200 mm-300 mm epitaxial device base in situ

The invention relates to a method for cleaning the back face of a 200 mm-300 mm epitaxial device base in situ. The method includes the steps of arranging an HC1/H2 mixer at an auxiliary gas inlet, premixing HC1 and H2, introducing the mixture into a reaction chamber, and controlling the mixing ratio of HC1 and H2 introduced during epitaxial growth and reaction chamber cleaning. Silicon depositing on a preheated ring and the back face of the base and adsorbed dopant impurities are effectively cleaned away, the addition of the impurities on the back face can be effectively restrained, the uniformity and stability of the temperature field on the base are improved, and the quality and stability of a 200 mm-300 mm silicon epitaxial wafer are improved. 本发明涉及一种原位清洗200mm-300mm外延设备基座背面的方法，包括：在副进气口设置HCl/H混合器，HCl和H预先混合后通入反应腔室，控制外延生长时和反应腔室清洗时通入的HCl和H的混合比例。本发明使得沉积在预热环和基座背面的硅和吸附的掺杂剂杂质得到了有效的清洗，可有效地抑制背景杂质的增加并提高基座上温度场的均匀性和稳定性，从而提升200mm-300mm硅外延片质量及其稳定性。