SEMICONDUCTOR DEVICE AND MANUFACTURE THEREOF

摘要

PROBLEM TO BE SOLVED: To enable to controllably add (dope) impurity element belonging to groups XIII and XV to a crystalline semiconductor film containing silicon, by doping with impurities through a thin insulating film to form a low concentration impurity region (an LDD region). SOLUTION: After a resist mask 109 is removed, an insulating film 111a for forming a low concentration impurity region (an LDD region) is formed. For example, a silicon oxide film is formed as the insulating film 111a by a plasma CVD method. Subsequently, a step of adding impurity element for giving n-type is executed to form a second impurity region (n-type region) 112 on the crystalline semiconductor film on which the insulating film 111a is formed on the surface thereof. In this case, in order to add impurities to the crystalline semiconductor film below the insulating film 111a via the insulating film 111a, suitable doping conditions are determined in consideration of the thickness of the insulating film 111a. A second impurity region 112 formed by this way functions as the low concentration impurity region (the LDD region).