MANUFACTURE OF SEMICONDUCTOR DEVICE

PURPOSE:To flatten a film at low temperature without lowering the quality of the film by stacking a BPSG film or a PSG film high in the concentration of impurity on an uneven substrate, and then, stacking an SiO2 film, or a BPSG film or a PSG film low in concentration of impurity, and further, heat-treating it. CONSTITUTION:A poly-Si film 3 is formed on the SiO2 film 2 on an Si substrate 1, and it is patterned. Next, the Si substrate 1 is accommodated in a chamber, and a BPSG film 4 high in concentration of impurity is stacked on the poly-Si film 3 by the CVD method of TEOS-TMOP-TIMB-O3 line. Next, the supply of impurity gas is stopped, and an SiO2 film 5 is stacked on the BPSG film 4. Next, a wafer is taken out of the chamber, and reflow treatment is performed at 800 deg.C under N2 atmosphere. Hereby, it becomes a BPSG film 6 being equalized as a whole, and the surface of the substrate becomes flat.