Method for manufacturing semiconductor device

摘要

A semiconductor device including an oxide semiconductor, which has stable electric characteristics and high reliability, is provided. In a method for manufacturing a transistor including an oxide semiconductor film, an implantation step where rare gas ions are implanted to the oxide semiconductor film is performed, and the oxide semiconductor film to which rare gas ions are implanted is subjected to a heating step under reduced pressure, in a nitrogen atmosphere, or in a rare gas atmosphere, whereby hydrogen or water contained in the oxide semiconductor film to which rare gas ions are implanted is released; thus, the oxide semiconductor film is highly purified.

主权项

1. A method for manufacturing a semiconductor device, comprising the steps of:
forming an oxide semiconductor film; forming a void into the oxide semiconductor film by an implantation step for implanting a noble gas ion inside the oxide semiconductor film; exposing the oxide semiconductor film after the implantation step; and performing a heating step under reduced pressure, in a nitrogen atmosphere, or in a noble gas atmosphere on the exposed oxide semiconductor film, so that hydrogen or water contained in the oxide semiconductor film is released through the void, wherein a peak of a concentration of an implanted noble gas element in the oxide semiconductor film is greater than or equal to 1×1019 atoms/cm3 and less than or equal to 3×1022 atoms/cm3 in the implantation step, wherein an ion implantation method, an ion doping method, or a plasma immersion ion implantation method is used for the implantation step, and wherein the oxide semiconductor film to which the noble gas ion is implanted is a channel formation region of a transistor.