Semiconductor device and manufacturing method thereof

Abstract

A minute transistor is provided. A transistor with low parasitic capacitance is provided. A transistor having high frequency characteristics is provided. A semiconductor device including the transistor is provided. A semiconductor device includes an oxide semiconductor, a first conductor, a second conductor, a third conductor, a first insulator, and a second insulator. The first conductor overlaps with the oxide semiconductor with the first insulator positioned therebetween. The second insulator has an opening and a side surface of the second insulator overlaps with a side surface of the first conductor in the opening with the first insulator positioned therebetween. Part of a surface of the second conductor and part of a surface of the third conductor are in contact with the first insulator in the opening. The oxide semiconductor overlaps with the second conductor and the third conductor.

1 . A semiconductor device comprising:
 a first transistor comprising a channel formation region in a semiconductor substrate;   a first insulator over the semiconductor substrate;   a first conductor functioning as a first gate electrode of the first transistor over the first insulator;   a second transistor over the first transistor comprising an oxide semiconductor in a channel formation region; and   a capacitor over the second transistor,   wherein one of a source and a drain of the first transistor is electrically connected to one of a source and a drain of the second transistor,   wherein the first gate electrode of the first transistor is electrically connected to the other of the source and the drain of the second transistor and one electrode of the capacitor,   wherein a second insulator is provided over the channel formation region of the second transistor, and   wherein a second conductor functioning as a first gate electrode of the second transistor is provided over the second insulator.   
     
     
         2 . A semiconductor device comprising:
 a first transistor comprising silicon in a channel formation region;   a first insulator over the channel formation region of the first transistor;   a first conductor functioning as a first gate electrode of the first transistor over the first insulator;   a second transistor overlapping with the first transistor comprising an oxide semiconductor in a channel formation region; and   a capacitor overlapping with the second transistor,   wherein one of a source and a drain of the first transistor is electrically connected to one of a source and a drain of the second transistor via a first plurality of conductors provided in a first plurality of insulators,   wherein the first gate electrode of the first transistor is electrically connected to the other of the source and the drain of the second transistor and one electrode of the capacitor via a second plurality of conductors provided in the first plurality of insulators,   wherein the other of the source and the drain of the first transistor is electrically connected to a conductor provided over the capacitor,   wherein a second insulator is provided over the channel formation region of the second transistor,   wherein a second conductor functioning as a first gate electrode of the second transistor is provided over the second insulator.   
     
     
         3 . A semiconductor device comprising:
 a first transistor comprising silicon in a channel formation region;   a first insulator over the channel formation region of the first transistor;   a first conductor functioning as a first gate electrode of the first transistor over the first insulator;   a second transistor overlapping with the first transistor comprising an oxide semiconductor in a channel formation region; and   a capacitor overlapping with the second transistor,   wherein a second insulator is provided over the channel formation region of the second transistor,   wherein a second conductor functioning as a first gate electrode of the second transistor is provided over the second insulator,   wherein one of a source and a drain of the first transistor is electrically connected to one of a source and a drain of the second transistor via a third conductor provided over the second conductor,   wherein the first gate electrode of the first transistor is electrically connected to the other of the source and the drain of the second transistor and one electrode of the capacitor via a fourth conductor provided over the second conductor,   wherein the other of the source and the drain of the first transistor is electrically connected to a fifth conductor provided over the other electrode of the capacitor, and   wherein the other electrode of the capacitor overlaps at least one of the second conductor, the first conductor, the channel formation region of the first transistor, and the channel formation region of the second transistor.   
     
     
         4 . The semiconductor device according to  claim 1 ,
 wherein the oxide semiconductor comprises at least two of indium, gallium, zinc, and tin,   wherein the channel formation region of the second transistor is provided on a protrusion of a third insulator provided over the first conductor, and   wherein source and drain regions of the first transistor overlap with source and drain regions of the second transistor.   
     
     
         5 . The semiconductor device according to  claim 2 ,
 wherein the oxide semiconductor comprises at least two of indium, gallium, zinc, and tin,   wherein the channel formation region of the second transistor is provided on a protrusion of a third insulator provided over the first conductor, and   wherein source and drain regions of the first transistor overlap with source and drain regions of the second transistor.   
     
     
         6 . The semiconductor device according to  claim 3 ,
 wherein the oxide semiconductor comprises at least two of indium, gallium, zinc, and tin,   wherein the channel formation region of the second transistor is provided on a protrusion of a third insulator provided over the first conductor, and   wherein source and drain regions of the first transistor overlap with source and drain regions of the second transistor.   
     
     
         7 . The semiconductor device according to  claim 1 ,
 wherein a portion of a fourth insulator is embedded in the oxide semiconductor,   wherein a fifth insulator is in contact with a side surface of the second insulator, and   wherein a sixth insulator is in contact with a side surface of the fifth insulator.   
     
     
         8 . The semiconductor device according to  claim 1 ,
 wherein the one electrode of the capacitor surrounds the other electrode of the capacitor.   
     
     
         9 . The semiconductor device according to  claim 2 ,
 wherein the one electrode of the capacitor surrounds the other electrode of the capacitor.   
     
     
         10 . The semiconductor device according to  claim 3 ,
 wherein the one electrode of the capacitor surrounds the other electrode of the capacitor.