Thin film transistor using oxide semiconductor, and semiconductor device including the same
The present invention addresses the problem of: realizing a TFT that uses an oxide semiconductor and that is capable of maintaining stable characteristics even in the case where the TFT is miniaturized; and realizing a display device that has high-definition pixels using such a TFT. To solve this problem, the present invention has the following configuration. A semiconductor device including an oxide semiconductor TFT formed using an oxide semiconductor film 109 , the semiconductor device being characterized in that: the channel length of the oxide semiconductor TFT is 1.3 to 2.3 μm; and the sheet resistance of a source region 1092 and a drain region 1091 of the oxide semiconductor film 109 is 1.4 to 20 KΩ/□.
1 . A thin film transistor comprising:
an oxide semiconductor,
a gate electrode formed of a metal layer, and
a gate insulating film formed between the oxide semiconductor and the gate electrode,
wherein the oxide semiconductor has a channel region corresponding to the gate electrode, and a source region and a drain region adjacent to the channel region,
a channel length of the channel region is 1.3 to 2.3 μm,
a sheet resistance of the drain region and the source region is 1.4 KΩ/□ to 20 KΩ/□,
the gate insulating film is a first silicon oxide film, and the drain region and the source region are covered with the gate insulating film and are in contact with the gate insulating film,
a silicon nitride film is formed on the gate insulating film corresponding to the source region and the drain region, and a second silicon oxide film is formed on the silicon nitride film,
each of the drain region and the source region has an oxygen-deficient portion formed by ions doped by ion implantation, and
the amount of hydrogen supplied from the silicon nitride film to the oxide semiconductor is less than the amount of hydrogen that can be taken into the oxygen-deficient regions.
2 . The thin film transistor according to claim 1 ,
wherein the sheet resistance of the drain region and the source region is 3 KΩ/□to 10 KΩ/□.
3 . The thin film transistor according to claim 1 ,
wherein the hydrogen supplied from the silicon nitride film to the oxide semiconductor is taken into the oxygen-deficient portion and does not migrate to the channel region.
4 . The thin film transistor according to claim 1 ,
wherein the drain region and the source region are doped with boron (B) by ion implantation.
5 . The thin film transistor according to claim 2 ,
wherein the drain region and the source region are doped with boron (B) by ion implantation.
6 . The thin film transistor according to claim 3 ,
wherein the drain region and the source region are doped with boron (B) by ion implantation.
7 . A semiconductor device comprising:
a substrate,
an oxide semiconductor formed on the substrate,
a first insulating film formed on the oxide semiconductor,
a metal layer formed on the first insulating film
a source electrode and a drain electrode electrically connected to the oxide semiconductor, and
a second insulating film formed on the first insulating film and the metal layer,
wherein the oxide semiconductor has a channel region corresponding to the metal layer, a source region adjacent to the channel region and electrically connected to the source electrode, and a drain region adjacent to the channel region and electrically connected to the drain electrode,
a channel length of the channel region is 1.3 to 2.3 μm,
a sheet resistance of the drain region and the source region is 1.4 KΩ/□to 20 KΩ/□,
the first insulating film is a first silicon oxide film, and the drain region and the source region are covered with the first insulating film and are in contact with the first insulating film,
the second insulating film includes a silicon nitride film formed on the first insulating film corresponding to the source region and the drain region, and a second silicon oxide film formed on the silicon nitride film,
each of the drain region and the source region has an oxygen-deficient portion formed by ions doped by ion implantation, and
the amount of hydrogen supplied from the silicon nitride film to the oxide semiconductor is less than the amount of hydrogen that can be taken into the oxygen-deficient regions.
8 . The semiconductor device according to claim 7 ,
wherein the hydrogen supplied from the silicon nitride film to the oxide semiconductor is taken into the oxygen-deficient portion and does not migrate to the channel region.