Semiconductor device and manufacturing method thereof

Abstract

A semiconductor device capable of high speed operation is provided. Further, a highly reliable semiconductor device is provided. An oxide semiconductor having crystallinity is used for a semiconductor layer of a transistor. A channel formation region, a source region, and a drain region are formed in the semiconductor layer. The source region and the drain region are formed in such a manner that one or more of elements selected from rare gases and hydrogen are added to the semiconductor layer by an ion doping method or an ion implantation method with the use of a channel protective layer as a mask.

1 . (canceled) 
     
     
         2 . A semiconductor device comprising:
 a first transistor, a second transistor and a third transistor,   wherein the first transistor includes silicon in a first channel formation region,   wherein the second transistor includes a first insulating layer containing oxygen, an oxide semiconductor in a second channel formation region over the first insulating layer, a second insulating layer over the oxide semiconductor, a gate electrode over the second insulating layer, and a third insulating layer containing silicon oxide over the gate electrode,   wherein the third transistor includes silicon in a third channel formation region,   wherein one of a source electrode and a drain electrode of the second transistor is electrically connected to a gate of the first transistor,   wherein one of a source electrode and a drain electrode of the first transistor is electrically connected to one of a source electrode and a drain electrode of the third transistor,   wherein the other of the source electrode and the drain electrode of the second transistor is electrically connected to a first wiring, and   wherein the other of the source electrode and the drain electrode of the third transistor is electrically connected to a second wiring different from the first wiring.   
     
     
         3 . A semiconductor device comprising:
 a first transistor, a second transistor and a third transistor,   wherein the first transistor includes silicon in a first channel formation region,   wherein the second transistor includes a first insulating layer containing oxygen, a source electrode and a drain electrode over the first insulating layer, an oxide semiconductor in a second channel formation region over the first insulating layer and over the source electrode and the drain electrode, a second insulating layer over the oxide semiconductor, a gate electrode over the second insulating layer, and a third insulating layer containing silicon oxide over the gate electrode,   wherein the third transistor includes silicon in a third channel formation region,   wherein one of the source electrode and the drain electrode of the second transistor is electrically connected to a gate of the first transistor,   wherein one of a source electrode and a drain electrode of the first transistor is electrically connected to one of a source electrode and a drain electrode of the third transistor,   wherein the other of the source electrode and the drain electrode of the second transistor is electrically connected to a first wiring, and   wherein the other of the source electrode and the drain electrode of the third transistor is electrically connected to a second wiring different from the first wiring.