| 摘要 |
PURPOSE:To inhibit a lateral diffusion on the activation of an impurity implanted to a semiconductor substrate,and to form a thin-film transistor having short gate length by designing the thickness of a semiconductor film in an extent that the standard deviation of the range of implanting ions is added to the flight range of the ions. CONSTITUTION:A polycrystalline silicon film 11 is formed onto insulating substrate 10 through a thin-film manufacture technique such as CVD. The polycrystalline silicon film 11 is formed so that film thickness thereof is brought to an extent that the standard deviation DELTARP of the range RP of implanting ions is added to the range of the ions. The range RP changes by the kinds of impurities and implantation energy, and is determined so as to be positioned at approximately the center of the thickness of the polycrystalline silicon film. Accordingly, a space in which the impurity can be diffused in the depth direction is shortened, thus cutting down the heat treatment time for implanting ions, then inhibiting the lateral diffusion of the impurity. |
