Abstract: In a manufacturing process of a semiconductor device formed using a thin film transistor, an object is to provide a technique by which the number of photomasks can be reduced, manufacturing cost can be reduced, and improvement in productivity and reliability can be achieved. A main point is that a film forming a channel protective layer is formed over an oxide semiconductor layer having a light-transmitting property, a positive photoresist is formed over the film forming a channel protective layer, and a channel protective layer is selectively formed over a channel formation region in the oxide semiconductor layer by using a back surface light exposure method.

Abstract: In a manufacturing process of a semiconductor device formed using a thin film transistor, an object is to provide a technique by which the number of photomasks can be reduced, manufacturing cost can be reduced, and improvement in productivity and reliability can be achieved. A main point is that a film forming a channel protective layer is formed over an oxide semiconductor layer having a light-transmitting property, a positive photoresist is formed over the film forming a channel protective layer, and a channel protective layer is selectively formed over a channel formation region in the oxide semiconductor layer by using a back surface light exposure method.

Abstract: The present invention provides a method for producing a crystalline metal oxide thin film by first depositing a substantially amorphous metal oxide film, and thereafter, as a post treatment, exposing the film to low temperature plasma in a high frequency electric field at 180° C. or less, and the crystalline metal oxide thin film produced by this method. Because the producing method according to the present invention allows a dense and homogenous crystalline metal oxide thin film to be formed onto a substrate at a low temperature without requiring active heat treatment, a metal oxide thin film having desirable characteristics can be formed without damaging the characteristics of a substrate even if the substrate has comparatively low heat resistance.

Abstract: The present invention provides a method for producing a crystalline metal oxide thin film by first depositing a substantially amorphous metal oxide film, and thereafter, as a post treatment, exposing the film to low temperature plasma in a high frequency electric field at 180° C. or less, and the crystalline metal oxide thin film produced by this method. Because the producing method according to the present invention allows a dense and homogenous crystalline metal oxide thin film to be formed onto a substrate at a low temperature without requiring active heat treatment, a metal oxide thin film having desirable characteristics can be formed without damaging the characteristics of a substrate even if the substrate has comparatively low heat resistance.

Abstract: A thin film silicon semiconductor device provided on a substrate according to the present invention comprises a thin polycrystalline silicon film having a lattice constant smaller than that of a silicon single crystal and a small crystal grain size. This thin polycrystalline silicon film can be obtained by depositing a thin amorphous silicon film in an inert gas having a pressure of 3.5 Pa or lower by a sputtering deposition method and annealing the thin amorphous silicon film for a short time of 10 seconds or less to effect polycrystallization thereof. A thin film silicon semiconductor device comprising such a thin polycrystalline silicon film having a small lattice constant has excellent characteristics including a carrier mobility of 100 cm.sup.2 /V.multidot.s or higher.

Abstract: A thin film silicon semiconductor device provided on a substrate according to the present invention comprises a thin polycrystalline silicon film having a lattice constant smaller than that of a silicon single crystal and a small crystal grain size. This thin polycrystalline silicon film can be obtained by depositing a thin amorphous silicon film in an inert gas having a pressure of 3.5 Pa or lower by a sputtering deposition method and annealing the thin amorphous silicon film for a short time of 10 seconds or less to effect polycrystallization thereof. A thin film silicon semiconductor device comprising such a thin polycrystalline silicon film having a small lattice constant has excellent characteristics including a carrier mobility of 100 cm.sup.2 /V.multidot.s or higher.