Patent ID: 7674721

Claim:
A method of forming a multi-layered insulation film on a semiconductor wafer, comprising: forming by a plasma CVD method a methyl silsesquioxane (MSQ) layer using a first feed gas; forming a methylated hydrogen silsesquioxane (MHSQ) layer using a second feed gas, such that the methylated hydrogen silsesquioxane (MHSQ) layer is in contact with a top of the methyl silsesquioxane (MSQ) layer; and forming an inorganic insulation layer such that the inorganic insulation layer is in contact with a top of the methylated hydrogen silsesquioxane (MHSQ) layer, wherein said methylated hydrogen silsesquioxane (MHSQ) layer is highly adhesive, wherein said methylated hydrogen silsesquioxane (MHSQ) layer is formed by a plasma CVD method, said semiconductor wafer being maintained in a plasma atmosphere between said forming said methyl silsesquioxane (MSQ) layer and forming said methylated hydrogen silsesquioxane (MHSQ) layer, wherein said first feed gas comprises a mixed gas of alkylsilane gas and oxidizing gas, and wherein said second feed gas comprises a mixed gas of monosilane gas, alkylsilane gas and oxidizing gas.