Manufacture of thin film transistor

Abstract

Abstract PURPOSE:To render the distribution of impurity concentration in a thin film uniform by a method wherein ion implantation is performed plural times at different energy level, where the area of peak concentration differs at each ion implantation. CONSTITUTION:Ion implantation is performed two times so as to form an impurity region, where the first arsenic ion implantation is performed, for instance, at 25KeV and with doses of 5X10<15>/cm<2>. The ion implantation is performed so as to render the area of a peak concentration to be near the surface of a semiconductor thin film 3. Next, the second arsenic ion implantation is performed at 70KeV and with doses of 5X10<15>/cm<2> for the formation of a source region 6 and a drain region 7. The ion implantation is performed so as to render the area of a peak concentration to be positioned at the depth of half the thickness of the semiconductor thin film 3. By these processes, the concentration of a impurity region can be made to be uniform in distribution, so that the sheet resistance can be rendered small.

Inventors

• 👤 Takefumi Oshima
• 👤 大嶋　健文
• 👤 Mitsuko Mochizuki
• 👤 望月　光子

Bibliographic Details