Semiconductor device, display device including the semiconductor device, display module including the display device, and electronic appliance including the semiconductor device, the display device, and the display module

Abstract

A change in electrical characteristics is inhibited and reliability is improved in a semiconductor device using a transistor including an oxide semiconductor. One embodiment of a semiconductor device including a transistor includes a gate electrode, first and second insulating films over the gate electrode, an oxide semiconductor film over the second insulating film, and source and drain electrodes electrically connected to the oxide semiconductor film. A third insulating film is provided over the transistor and a fourth insulating film is provided over the third insulating film. The third insulating film includes oxygen. The fourth insulating film includes nitrogen. The amount of oxygen released from the third insulating film is 1×1019/cm3 or more by thermal desorption spectroscopy, which is estimated as oxygen molecules. The amount of oxygen molecules released from the fourth insulating film is less than 1×1019/cm3.

What is claimed is: 
     
         1 . A semiconductor device comprising:
 a gate electrode;   a gate insulating film over the gate electrode;   an oxide semiconductor film over the gate insulating film;   a source electrode and a drain electrode on and in contact with the oxide semiconductor film;   a first insulating film on and in contact with the source electrode, the drain electrode, and the oxide semiconductor film; and   a second insulating film over the first insulating film,   wherein the gate insulating film includes a first layer comprising silicon nitride and a second layer comprising silicon oxynitride on the first layer,   wherein the first insulating film comprises silicon oxynitride,   wherein the second insulating film comprises silicon nitride,   wherein a thickness of the first insulating film is larger than a thickness of the second insulating film and a thickness of the third insulating film, and   wherein a region of the first insulating film has a spin density corresponding to a signal that appears at g=2.001 lower than 1.5×10 18  spins/cm 3  by electron spin resonance measurement.   
     
     
         2 . The semiconductor device according to  claim 1 ,
 wherein the oxide semiconductor film is provided on and in contact with the second layer of the gate insulating film   
     
     
         3 . The semiconductor device according to  claim 1 ,
 wherein the oxide semiconductor film comprises In, Zn, and Ga.   
     
     
         4 . The semiconductor device according to  claim 1 ,
 wherein the oxide semiconductor film includes a crystal part, and   wherein the crystal part includes a portion having c-axis alignment.   
     
     
         5 . The semiconductor device according to  claim 1 ,
 wherein the signal that appears at g=2.001 is due to dangling bonds of silicon in the first insulating film   
     
     
         6 . The semiconductor device according to  claim 1 ,
 wherein the first insulating film includes a first layer and a second layer on the first layer, and   wherein the region is included in the second layer of the first insulating film.   
     
     
         7 . The semiconductor device according to  claim 1 ,
 wherein an amount of oxygen molecules released from each of the first insulating film is greater than or equal to b  1 × 10   19 /cm 3  when measured by thermal desorption spectroscopy.   
     
     
         8 . The semiconductor device according to  claim 1 ,
 wherein an amount of oxygen molecules released from the second insulating film is less than 1×10 19 /cm 3  when measured by the thermal desorption spectroscopy.   
     
     
         9 . A display device comprising the semiconductor device according to  claim 1 . 
     
     
         10 . A display module comprising:
 the display device according to  claim 1 ; and   a touch sensor.   
     
     
         11 . An electronic appliance comprising:
 the semiconductor device according to  claim 1 ; and   at least one of an operation key and a battery.   
     
     
         12 . A semiconductor device comprising:
 a gate electrode;   a first insulating film over the gate electrode;   a second insulating film on and in contact with the first insulating film;   an oxide semiconductor film on and in contact with the second insulating film;   a source electrode and a drain electrode on and in contact with first regions of the oxide semiconductor film;   a third insulating film on and in contact with the source electrode, the drain electrode, and a second region of the oxide semiconductor film; and   a fourth insulating film over the third insulating film,   wherein each of the second insulating film and the third insulating film comprises silicon oxynitride,   wherein each of the first insulating film and the fourth insulating film comprises silicon nitride,   wherein a thickness of the third insulating film is larger than a thickness of the fourth insulating film, and   wherein a region of the third insulating film has a spin density corresponding to a signal that appears at g=2.001 lower than 1.5×10 18  spins/cm 3  by electron spin resonance measurement.   
     
     
         13 . The semiconductor device according to  claim 12 ,
 wherein the oxide semiconductor film comprises In, Zn, and Ga.   
     
     
         14 . The semiconductor device according to  claim 12 ,
 wherein the oxide semiconductor film includes a crystal part, and   wherein the crystal part includes a portion having c-axis alignment.   
     
     
         15 . The semiconductor device according to  claim 12 ,
 wherein the signal that appears at g=2.001 is due to dangling bonds of silicon in the third insulating film   
     
     
         16 . The semiconductor device according to  claim 12 ,
 wherein the third insulating film includes a first layer and a second layer on the first layer, and   wherein the region is included in the second layer of the third insulating film   
     
     
         17 . The semiconductor device according to  claim 12 , wherein an amount of oxygen molecules released from the third insulating film is greater than or equal to 1×10 19 /cm 3  when measured by thermal desorption spectroscopy. 
     
     
         18 . The semiconductor device according to  claim 12 ,
 wherein an amount of oxygen molecules released from the fourth insulating film is less than 1×10 19 /cm 3  when measured by the thermal desorption spectroscopy.   
     
     
         19 . A display device comprising the semiconductor device according to  claim 12 . 
     
     
         20 . A display module comprising:
 the display device according to  claim 19 ; and   a touch sensor.   
     
     
         21 . An electronic appliance comprising:
 the semiconductor device according to  claim 12 ; and   at least one of an operation key and a battery.   
     
     
         22 . A semiconductor device comprising:
 a gate electrode;   a gate insulating film over the gate electrode;   an oxide semiconductor film over the gate insulating film;   a source electrode and a drain electrode on and in contact with the oxide semiconductor film;   a first insulating film on and in contact with the source electrode, the drain electrode, and the oxide semiconductor film; and   a second insulating film over the first insulating film,   wherein the gate insulating film includes a first layer comprising silicon nitride and a second layer comprising silicon oxynitride on the first layer,   wherein the first insulating film comprises silicon oxynitride,   wherein the second insulating film comprises silicon nitride, and   wherein a thickness of the first insulating film is larger than a thickness of the second insulating film   
     
     
         23 . The semiconductor device according to  claim 22 ,
 wherein the oxide semiconductor film is provided on and in contact with the second layer of the gate insulating film   
     
     
         24 . The semiconductor device according to  claim 22 ,
 wherein the oxide semiconductor film comprises In, Zn, and Ga.   
     
     
         25 . The semiconductor device according to  claim 22 ,
 wherein the oxide semiconductor film includes a crystal part, and   wherein the crystal part includes a portion having c-axis alignment.   
     
     
         26 . The semiconductor device according to  claim 22 ,
 wherein the first insulating film includes a first layer and a second layer on the first layer.   
     
     
         27 . A display device comprising the semiconductor device according to  claim 22 . 
     
     
         28 . A display module comprising:
 the display device according to  claim 27 ; and   a touch sensor.   
     
     
         29 . An electronic appliance comprising:
 the semiconductor device according to  claim 22 ; and   at least one of an operation key and a battery.