METHOD OF DETECTING DEFECTS IN CVD FILM

PURPOSE:To detects in a BPSG film right after accumulation by flattening the BPSG film, which is accumulated by CVD method, by heat treatment, and then measuring it with a wafer defect detector. CONSTITUTION:A BPSG film 2 of 300mum or more in thickness, which contains 1-3wt.% boron and 6-7wt.% phosphorus, is accumulated by CVD method. And it is heat-treated at 900 deg.C for 15-30 minutes in N2 atmosphere, and then the defects at the surface of the BPSG film 2 are measured with a wafer surface defect detector. That is, when heat treatment is done, the surface of the BPSG film 2 reaches the softening temperature, and the grains are flattened by its viscosity, while the foreign matter 3, which were adhering to the wafer surface, remains on the surface of the flattening BPSG film 2 without being affected by heat treatment. Hereby, the scattered light of the wafer defect detector is not affected by the effect of the grains, and only the actual foreign matter 3 can be detected as the defects of the BPSG film 2.