Semiconductor device

• US 10,367,013 B2
• Filed: 12/18/2017
• Issued: 07/30/2019
• Est. Priority Date: 02/07/2014
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Koezuka, Junichi, Jintyou, Masami, Shima, Yukinori, Kurosaki, Daisuke, Nakada, Masataka, Yamazaki, Shunpei
• Primary Examiner(s): Tran, Tony
• Application Number:
  US15/845,692
• Publication Number:
  US 20180151603A1
• Time in Patent Office: 589 Days
• 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 27/1237 with a different composition, shape, layout or thickness of the gate insulator in different devices
• CPC Class Codes: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/1251 comprising TFTs having a different architecture, e.g. top- and bottom gate TFTs
• CPC Class Codes: H01L 29/78603 characterised by the insulating substrate or support H01L29/78657 takes precedence
• CPC Class Codes: H01L 29/78645 with multiple gate
• CPC Class Codes: H01L 29/78648 arranged on opposing sides of the channel
• 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

A semiconductor device including an oxide semiconductor in which on-state current is high is provided. The semiconductor device includes a first transistor provided in a driver circuit portion and a second transistor provided in a pixel portion; the first transistor and the second transistor have different structures. Furthermore, the first transistor and the second transistor are transistors having a top-gate structure. In an oxide semiconductor film of each of the transistors, an impurity element is contained in regions which do not overlap with a gate electrode. The regions of the oxide semiconductor film which contain the impurity element function as low-resistance regions. Furthermore, the regions of the oxide semiconductor film which contain the impurity element are in contact with a film containing hydrogen. The first transistor provided in the driver circuit portion includes two gate electrodes between which the oxide semiconductor film is provided.

Claims

1. A semiconductor device comprising:

a substrate;

a first transistor over the substrate, the first transistor including;

a conductive film over the substrate;

a first insulating film over the conductive film;

a first oxide semiconductor film over the first insulating film, the first oxide semiconductor film overlapping with the conductive film;

a first gate insulating film on the first oxide semiconductor film;

a first gate electrode over the first insulating film;

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

a first source electrode and a first drain electrode over and in direct contact with the first oxide semiconductor film through first openings provided in the second insulating film,

wherein the first oxide semiconductor film includes a first region being in directly contact with the first gate insulating film and second regions being in directly contact with the second insulating film, and

wherein each of the second regions of the first oxide semiconductor film has lower resistance than the first region of the first oxide semiconductor film; and

a second transistor over the substrate, the second transistor including;

a second oxide semiconductor film over the first insulating film;

a second gate insulating film on the second oxide semiconductor film;

a second gate electrode over the second gate insulating film;

the second insulating film on the second oxide semiconductor film and the second gate electrode; and

a second source electrode and a second drain electrode over and in direct contact with the second oxide semiconductor film through second openings provided in the second insulating film,

wherein the second oxide semiconductor film includes a first region being in directly contact with the second gate insulating film and second regions being in directly contact with the second insulating film, and wherein each of the second regions of the second oxide semiconductor film has lower resistance than the first region of the second oxide semiconductor film.

2. The semiconductor device according to claim 1, wherein the second insulating film comprises hydrogen.

3. The semiconductor device according to claim 1, wherein the second insulating film comprises oxygen.

4. The semiconductor device according to claim 1,

wherein each of the second regions of the first oxide semiconductor film has a higher concentration in impurity elements than the first region of the first oxide semiconductor film, and

wherein each of the second regions of the second oxide semiconductor film has a higher concentration in the impurity elements than the first region of the second oxide semiconductor film.

5. The semiconductor device according to claim 4, wherein the impurity elements are selected from the group consisting of hydrogen, boron, carbon, nitrogen, fluorine, aluminum, silicon, phosphorus, chlorine, helium, neon, argon, krypton, and xenon.

6. The semiconductor device according to claim 1, wherein the conductive film is configured to be a back-gate electrode of the first transistor.

7. The semiconductor device according to claim 1, wherein the second transistor has a single-gate structure.

8. The semiconductor device according to claim 1, wherein the first transistor is provided in a driver circuit portion and the second transistor is provided in a pixel portion.

9. A semiconductor device comprising:

a substrate;

a first transistor over the substrate, the first transistor including;

a conductive film over the substrate;

a first insulating film over the conductive film;

a first oxide semiconductor film over the first insulating film, the first oxide semiconductor film overlapping with the conductive film;

a first gate insulating film on the first oxide semiconductor film;

a first gate electrode over the first insulating film;

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

a third insulating film on the second insulating film; and

a first source electrode and a first drain electrode over and in direct contact with the first oxide semiconductor film through first openings provided in the second insulating film and the third insulating film,

wherein the first oxide semiconductor film includes a first region being in directly contact with the first gate insulating film and second regions being in directly contact with the second insulating film, and

wherein each of the second regions of the first oxide semiconductor film has lower resistance than the first region of the first oxide semiconductor film; and

a second transistor over the substrate, the second transistor including;

a second oxide semiconductor film over the first insulating film;

a second gate insulating film on the second oxide semiconductor film;

a second gate electrode over the second gate insulating film;

the second insulating film on the second oxide semiconductor film and the second gate electrode;

the third insulating film on the second insulating film; and

a second source electrode and a second drain electrode over and in direct contact with the second oxide semiconductor film through second openings provided in the second insulating film and the third insulating film,

wherein the second oxide semiconductor film includes a first region being in directly contact with the second gate insulating film and second regions being in directly contact with the second insulating film, and

wherein each of the second regions of the second oxide semiconductor film has lower resistance than the first region of the second oxide semiconductor film.

10. The semiconductor device according to claim 9, wherein the second insulating film comprises hydrogen.

11. The semiconductor device according to claim 9, wherein the second insulating film comprises oxygen.

12. The semiconductor device according to claim 9, wherein the third insulating film comprises oxygen.

13. The semiconductor device according to claim 9,

wherein each of the second regions of the first oxide semiconductor film has a higher concentration in impurity elements than the first region of the first oxide semiconductor film, and

wherein each of the second regions of the second oxide semiconductor film has a higher concentration in the impurity elements than the first region of the second oxide semiconductor film.

14. The semiconductor device according to claim 13, wherein the impurity elements are selected from the group consisting of hydrogen, boron, carbon, nitrogen, fluorine, aluminum, silicon, phosphorus, chlorine, helium, neon, argon, krypton, and xenon.

15. The semiconductor device according to claim 9, wherein the conductive film is configured to be a back-gate electrode of the first transistor.

16. The semiconductor device according to claim 9, wherein the second transistor has a single-gate structure.

17. The semiconductor device according to claim 9, wherein the first transistor is provided in a driver circuit portion and the second transistor is provided in a pixel portion.

18. A semiconductor device comprising:

a substrate;

a first transistor over the substrate, the first transistor including;

a conductive film over the substrate;

a first insulating film over the conductive film, the first insulating film comprising oxygen;

a first oxide semiconductor film over the first insulating film, the first oxide semiconductor film overlapping with the conductive film;

a first gate insulating film on the first oxide semiconductor film;

a first gate electrode over the first insulating film;

a second insulating film on the first oxide semiconductor film and the first gate electrode, the second insulating film comprising oxygen;

a third insulating film on the second insulating film, the third insulating film comprising oxygen; and

a first source electrode and a first drain electrode over and in direct contact with the first oxide semiconductor film through first openings provided in the second insulating film and the third insulating film,

wherein the first oxide semiconductor film includes a first region being in directly contact with the first gate insulating film and second regions being in directly contact with the second insulating film, and

wherein each of the second regions of the first oxide semiconductor film has lower resistance than the first region of the first oxide semiconductor film; and

a second transistor over the substrate, the second transistor including;

a second oxide semiconductor film over the first insulating film;

a second gate insulating film on the second oxide semiconductor film;

a second gate electrode over the second gate insulating film;

the second insulating film on the second oxide semiconductor film and the second gate electrode;

the third insulating film on the second insulating film; and

a second source electrode and a second drain electrode over and in direct contact with the second oxide semiconductor film through second openings provided in the second insulating film and the third insulating film,

wherein the second oxide semiconductor film includes a first region being directly in contact with the second gate insulating film and second regions being in directly contact with the second insulating film, and

wherein each of the second regions of the second oxide semiconductor film has lower resistance than the first region of the second oxide semiconductor film.

19. The semiconductor device according to claim 18,

wherein each of the second regions of the first oxide semiconductor film has a higher concentration in impurity elements than the first region of the first oxide semiconductor film, and

wherein each of the second regions of the second oxide semiconductor film has a higher concentration in the impurity elements than the first region of the second oxide semiconductor film.

20. The semiconductor device according to claim 19, wherein the impurity elements are selected from the group consisting of hydrogen, boron, carbon, nitrogen, fluorine, aluminum, silicon, phosphorus, chlorine, helium, neon, argon, krypton, and xenon.

21. The semiconductor device according to claim 18, wherein the conductive film is configured to be a back-gate electrode of the first transistor.

22. The semiconductor device according to claim 18, wherein the second transistor has a single-gate structure.

23. The semiconductor device according to claim 18, wherein the first transistor is provided in a driver circuit portion and the second transistor is provided in a pixel portion.