Semiconductor device and method for manufacturing the same

摘要

Electrical characteristics of a semiconductor device including the oxide semiconductor are improved. Furthermore, a highly reliable transistor with small variation in electrical characteristics is manufactured. An oxynitride insulating film functioning as a base insulating film and a transistor in contact with the oxynitride insulating film are provided. The transistor includes an oxide semiconductor film in contact with the oxynitride insulating film functioning as a base insulating film. The total amount of gas having a mass-to-charge ratio of 30 released from the oxynitride insulating film by heat treatment and double of the amount of a gas having a mass-to-charge ratio of 32 released from the oxynitride insulating film by heat treatment is greater than or equal to 5×1015/cm2 and less than or equal to 5×1016/cm2, or greater than or equal to 5×1015/cm2 and less than or equal to 3×1016/cm2.

主权项

1. A method for manufacturing a semiconductor device comprising the steps of:
forming an oxynitride insulating film; forming an oxide semiconductor film over and in contact with the oxynitride insulating film; performing a heat treatment after forming the oxide semiconductor film; forming a pair of electrodes in contact with the oxide semiconductor film; forming a gate insulating film in contact with the oxide semiconductor film; and forming a gate electrode overlapping the oxide semiconductor film, wherein a total of an amount of a gas having a mass-to-charge ratio of 30 released from the oxynitride insulating film by the heat treatment and double of an amount of a gas having a mass-to-charge ratio of 32 released from the oxynitride insulating film by the heat treatment is greater than or equal to 5×1015/cm2 and less than or equal to 5×1016/cm2, and wherein the gas having a mass-to-charge ratio of 30 is nitrogen monoxide and the gas having a mass-to-charge ratio of 32 is oxygen.