Patent ID: 6989300
Filing Date: 2006-01-24
Classification: H01L

Abstract:
1. A method for forming a first-property semiconductor film at a desired position on a substrate, comprising the steps of: preparing the substrate having a second-property semiconductor film formed thereon in a gas atmosphere with a pressure of substantially atmospheric pressure; b) preparing an optical mask having a predetermined pattern on another substrate which is apart from the substrate; c) relatively positioning a projection area of the optical mask at the desired position on the substrate; d) irradiating the desired position of the second-property semiconductor film with laser light through the optical mask to change an irradiated portion of the second-property semiconductor film to the first-property semiconductor film; and e) forming an insulation film on the first-property semiconductor film and the second-property semiconductor film; wherein the optical mask has an alignment mark pattern, wherein, in the step (d), an alignment mark corresponding to the alignment mark pattern is formed by the irradiation of the desired portion of the second-property semiconductor film with the laser light through the optical mask to change the irradiated portion of the second-property semiconductor film to the first-property semiconductor film, and wherein the alignment mark is visible due to a difference in optical characteristic between the first-property semiconductor film and the second-property semiconductor film.