Semiconductor device

摘要

A nitride insulating film which prevents diffusion of hydrogen into an oxide semiconductor film in a transistor including an oxide semiconductor is provided. Further, a semiconductor device which has favorable electrical characteristics by using a transistor including a silicon semiconductor and a transistor including an oxide semiconductor is provided. Two nitride insulating films having different functions are provided between the transistor including a silicon semiconductor and the transistor including an oxide semiconductor. Specifically, a first nitride insulating film which contains hydrogen is provided over the transistor including a silicon semiconductor, and a second nitride insulating film which has a lower hydrogen content than the first nitride insulating film and functions as a barrier film against hydrogen is provided between the first nitride insulating film and the transistor including an oxide semiconductor.

主权项

1. A semiconductor device comprising:
a first transistor comprising a silicon semiconductor film including a first channel formation region; an insulating film comprising a first nitride insulating film and a second nitride insulating film over the first transistor; a second transistor comprising an oxide semiconductor film including a second channel formation region over the insulating film; and a third nitride insulating film over the second transistor, wherein the second nitride insulating film is provided between the first nitride insulating film and the oxide semiconductor film, wherein a hydrogen concentration of the second nitride insulating film is lower than a hydrogen concentration of the first nitride insulating film, wherein an etching rate of the second nitride insulating film is less than or equal to 2.0 nm/minute under a condition where etching is performed at a temperature higher than or equal to 20° C. and lower than or equal to 25° C. with the use of 0.5 wt % of hydrofluoric acid, and wherein an etching rate of the third nitride insulating film is less than or equal to 2.0 nm/minute under a condition where etching is performed at a temperature higher than or equal to 20° C. and lower than or equal to 25° C. with the use of 0.5 wt % of hydrofluoric acid.