Patent ID: 6703267
Filing Date: 2004-03-09
Classification: H01L

Abstract:
A method for manufacturing a thin film transistor, comprising the steps of:forming a silicon active layer on a substrate whose at least top surface is an insulator; forming a first silicon dioxide layer on a top surface of said silicon active layer by CVD using a mixed gas containing a silicon compound, oxygen and a first gas as a carrier gas; etching said silicon active layer and said first silicon dioxide layer simultaneously in such a manner that regions of said silicon active layer, which are adapted to be prospective channel, source and drain regions of the thin film transistor, are left unetched and that said first silicon dioxide layer becomes smaller in at least one of width or length than said channel, source and drain regions combined; and forming a second silicon dioxide layer, which covers said first silicon dioxide layer and said silicon active layer, by CVD using a mixed gas containing a silicon compound, oxygen and a second gas, which is larger in mass number than said first gas, as carrier gas.