TRANSISTOR

• US 20110121284A1
• Filed: 11/18/2010
• Published: 05/26/2011
• Est. Priority Date: 11/20/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Kawae, Daisuke
• Granted Patent: US 8,637,861 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 29/42392 fully surrounding the channel, e.g. gate-all-around
• CPC Class Codes: H01L 29/78606 with supplementary region or layer in the thin film or in the insulated bulk substrate supporting it for controlling or increasing the safety of the device H01L29/78642, H01L29/78645 take precedence
• CPC Class Codes: H01L 29/78642 Vertical transistors
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

Provided is a semiconductor device for high power application including a novel semiconductor material with high productivity. Alternatively, provided is a semiconductor device having a novel structure in which the novel semiconductor material is used. Provided is a vertical transistor including a channel formation region formed using an oxide semiconductor which has a wider band gap than a silicon semiconductor and is an intrinsic semiconductor or a substantially intrinsic semiconductor with impurities that serve as electron donors (donors) in the oxide semiconductor removed. The thickness of the oxide semiconductor is greater than or equal to 1 micrometer, preferably greater than 3 micrometer, more preferably greater than or equal to 10 micrometer.

Claims

1. A transistor comprising:

a first electrode formed over a substrate;

an oxide semiconductor film which is formed in contact with the first electrode and which has a reduced hydrogen concentration and a thickness of greater than 3 μ

m;

a second electrode formed in contact with the oxide semiconductor film;

a gate insulating film covering the first electrode, the oxide semiconductor film, and the second electrode; and

a third electrode faces at least a side surface of the oxide semiconductor film with the gate insulating film provided therebetween.

5. The transistor according to claim 1, wherein the second electrode is in contact with an entire top surface of the oxide semiconductor film.

9. The transistor according to claim 1, wherein the oxide semiconductor film has a carrier density of lower than 1×

10¹⁴ cm<sup>−

3</sup>.

13. The transistor according to claim 1, wherein the oxide semiconductor film has a carrier density of lower than 1×

10¹² cm<sup>−

3</sup>.

17. The transistor according to claim 1, wherein a channel is formed in an entire region of the semiconductor film.

2. A transistor comprising:

a first electrode formed over a substrate;

an oxide semiconductor film which is formed in contact with the first electrode and which has a reduced hydrogen concentration and a thickness of greater than 3 μ

m;

a second electrode formed in contact with the oxide semiconductor film;

a gate insulating film covering the first electrode, the oxide semiconductor film, and the second electrode; and

a third electrode faces at least a side surface of the oxide semiconductor film with the gate insulating film provided therebetween,

wherein the oxide semiconductor film includes a crystal region in a region that is in contact with the gate insulating film.

6. The transistor according to claim 2, wherein the second electrode is in contact with an entire top surface of the oxide semiconductor film.

10. The transistor according to claim 2, wherein the oxide semiconductor film has a carrier density of lower than 1×

10¹⁴ cm<sup>−

3</sup>.

14. The transistor according to claim 2, wherein the oxide semiconductor film has a carrier density of lower than 1×

10¹² cm<sup>−

3</sup>.

18. The transistor according to claim 2, wherein a channel is formed in an entire region of the semiconductor film.

3. A transistor comprising:

a first electrode formed over a substrate;

an oxide semiconductor film which is formed in contact with the first electrode and which has a reduced hydrogen concentration and a thickness of greater than 3 μ

m;

a second electrode formed in contact with the oxide semiconductor film;

a gate insulating film covering the first electrode, the oxide semiconductor film, and the second electrode; and

a third electrode faces at least a side surface of the oxide semiconductor film with the gate insulating film provided therebetween,

wherein the oxide semiconductor film includes a crystal region in a region that is in contact with the gate insulating film and,

wherein the first electrode functions as one of a source electrode and a drain electrode,

wherein the second electrode functions as the other of a source electrode and a drain electrode, and

wherein the third electrode functions as a gate electrode.

7. The transistor according to claim 3, wherein the second electrode is in contact with an entire top surface of the oxide semiconductor film.

11. The transistor according to claim 3, wherein the oxide semiconductor film has a carrier density of lower than 1×

10¹⁴ cm<sup>−

3</sup>.

15. The transistor according to claim 3, wherein the oxide semiconductor film has a carrier density of lower than 1×

10¹² cm<sup>−

3</sup>.

19. The transistor according to claim 3, wherein a channel is formed in an entire region of the semiconductor film.

4. A transistor comprising:

a first electrode formed over a substrate;

an oxide semiconductor film which is formed in contact with the first electrode and which has a reduced hydrogen concentration and a thickness of greater than 3 μ

m;

a second electrode formed in contact with the oxide semiconductor film;

a gate insulating film covering the first electrode, the oxide semiconductor film, and the second electrode; and

a third electrode faces at least a side surface of the oxide semiconductor film with the gate insulating film provided therebetween,

wherein the oxide semiconductor film includes a crystal region in a region that is in contact with the gate insulating film wherein the first electrode functions as one of a source electrode and a drain electrode,

wherein the second electrode functions as the other of a source electrode and a drain electrode, and

wherein the third electrode functions as a gate electrode.

8. The transistor according to claim 4, wherein the second electrode is in contact with an entire top surface of the oxide semiconductor film.

12. The transistor according to claim 4, wherein the oxide semiconductor film has a carrier density of lower than 1×

10¹⁴ cm<sup>−

3</sup>.

16. The transistor according to claim 4, wherein the oxide semiconductor film has a carrier density of lower than 1×

10¹² cm<sup>−

3</sup>.

20. The transistor according to claim 4, wherein a channel is formed in an entire region of the semiconductor film.