Patent ID: 8524580

Claim:
A manufacturing method of a semiconductor device, comprising: a first film forming step of forming a first thin film on a surface of a substrate placed in a processing chamber; and a second film forming step of forming a second thin film having the same element component as the first thin film on the first thin film after the first film forming step is performed, wherein the first film forming step comprises: a first step of supplying a first processing gas containing a first element into the processing chamber through a buffer chamber, the buffer chamber forming a gas dispersion space for uniformizing flow rat and flow velocity of gas within the buffer chamber; a second step of exhausting the first processing gas remained in the processing chamber; a third step of supplying a second processing gas containing a second element into the processing chamber through the buffer chamber; and a fourth step of exhausting the second processing gas remained in the processing chamber, wherein the first thin film is formed on the surface of the substrate, with the first to fourth steps set as one cycle and by repeating this cycle prescribed number of times, the second film forming step comprises: a fifth step of supplying into the processing, chamber through the buffer chamber, a third processing gas containing the first element, having an element component which is different from that of the first processing gas, and having a lower thermal decomposition property than that of the first processing gas; a sixth step of exhausting the third processing gas remained in the processing chamber; a seventh step of supplying the second processing gas containing the second element into the processing chamber through the buffer chamber; and an eighth step of exhausting the second processing gas remained in the processing chamber, wherein the second thin film is formed on the first thin film, with the fifth to eighth steps set as one cycle and by repeating this cycle prescribed number of times.