| 摘要 |
PURPOSE:To form a taper in an excellent reproducible manner without performing an additional process by a method wherein an aperture part having a taper is formed utilizing the high density of phosphorus of the BPSG film which is formed when a low temperature melting of BPSG is performed. CONSTITUTION:A source region 1a, a base region 1b, a channel 1c and a drain region 1d are formed on a substrate 1, and a gate insulating film 2, a polycrystalline silicon gate 3 and an aperture 4 are formed thereon. The BPSG film 5, as an interlayer insulating film, and a PSG film 6 are laminated thereon by performing a CVD method. Then, phosphorus is deposited on said laminated film, the low temperature melting of BPSG is performed, and a part of a high density PSG film 6a and a BPSG film 5a is removed by performing an etching. Utilizing the remaining surface layer 5a, a contact aperture part (taper angle of approximately 30 deg.) is formed by performing a chemical etching method, and a source electrode 8 and a gate electrode 9 are formed.
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