| 摘要 |
PROBLEM TO BE SOLVED: To provide a silicon nitride film whose controllability of film thickness is satisfactory, even if the film is thin through the means of a CVD method by providing trichlorosilane (SiCl4) and ammonia (NH3) on the surface of a processed object as raw gases. SOLUTION: N2 gas is supplied into a heat treatment container 8, where a temperature is maintained to that at which a natural oxide film is difficult to adhere. A water board 10 where the multiple stages of wafers W are kept is stored, the inner part of the container 8 is set to a sealed state, N2 gas is discharged, and ammonia (NH3) gas is continuously supplied instead. At processing a success film, tetrachlorosilane (SiCl4) is supplied, in addition to NH3 gas. At this time, it turns into 3SiCl4+4NH3=Si3N4+12HCl by thermal CVD method film forming reaction. Then, a silicon nitride (Si3N4) film is formed. The film is superior in insulating property. In particular leak current is less, the film can be thinned and the characteristic can be improved, when it is used as the insulating film of the capacitor of a semiconductor integrated circuit such as DRAMs.
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