| abstract |
The reliability of a semiconductor device is improved, and the manufacturing yield of the semiconductor device is improved. An insulating film is formed as an oxide film on a main surface of a semiconductor substrate, a silicon nitride film is formed on the insulating film, and an element isolation groove is formed by plasma dry etching. An insulating film 6 made of silicon oxide is formed by HDP-CVD so as to fill 4a, and the insulating film 6 outside the groove 4a is removed by CMP treatment, leaving the insulating film 6 in the groove 4a. Then, the silicon nitride film is removed. Thereafter, the insulating film 2 is removed by wet etching to expose the semiconductor substrate 1. At this time, the insulating film 2 is wet etched while applying light of 140 lux or more to the main surface of the semiconductor substrate 1. [Selection] Figure 14 |