Patent ID: 7442656

Claim:
A film formation method for a semiconductor process for forming a silicon oxide film on a target substrate by CVD, in a process field configured to be selectively supplied with a first process gas containing a chlorosilane family gas, a second process gas containing a Cl-replacing gas, and a third process gas containing an oxidizing gas, the method alternately comprising, in an order set forth below: a first step of performing supply of the first process gas to the process field while stopping supply of the second and third process gases to the process field; a second step of stopping supply of the first, second, and third process gases to the process field; a third step of performing supply of the second process gas to the process field while stopping supply of the first and third process gases to the process field, the third step comprising an excitation period of supplying the second process gas to the process field while exciting the second process gas by an exciting mechanism; a fourth step of stopping supply of the first, second, and third process gases to the process field; a fifth step of performing supply of the third process gas to the process field while stopping supply of the first and second process gases to the process field, the fifth step comprising an excitation period of supplying the third process gas to the process field while exciting the third process gas by an exciting mechanism; and a sixth step of stopping supply of the first, second, and third process gases to the process field.