Semiconductor device with an active layer containing zinc oxide, manufacturing method, and electronic device

• US 8,093,589 B2
• Filed: 06/14/2004
• Issued: 01/10/2012
• Est. Priority Date: 06/20/2003
• Status: Active Grant

• Current Assignee: Hideo Ohno, Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Masashi Kawasaki
• Original Assignee: Hideo Ohno, Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Masashi Kawasaki
• Inventors: Sugihara, Toshinori, Ohno, Hideo, Kawasaki, Masashi
• Primary Examiner(s): Kim, Jay C
• Application Number:
  US10/560,907
• Publication Number:
  US 20060244107A1
• Time in Patent Office: 2,766 Days
• Field of Search: 257/43, 257/613, 257/E21.372, 257/E29.273, 257/E27.06, 257/E29.169, 257/E29.242, 257/E21.051, 257/E21.4, 257/76, 257/78, 257/614, 257/E21.411, 257/E29.094, 257/E29.202, 257/E29.296
• US Class Current: 257/43
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

In a thin film transistor (1), a gate insulating layer (4) is formed on a gate electrode (3) formed on an insulating substrate (2). Formed on the gate insulating layer (4) is a semiconductor layer (5). Formed on the semiconductor layer (5) are a source electrode (6) and a drain electrode (7). A protective layer (8) covers them, so that the semiconductor layer (5) is blocked from an atmosphere. The semiconductor layer (5) (active layer) is made of, e.g., a semiconductor containing polycrystalline ZnO to which, e.g., a group V element is added. This allows practical use of a semiconductor device which has an active layer made of zinc oxide and which includes an protective layer for blocking the active layer from an atmosphere.

Claims

1. A semiconductor device comprising:

an active layer, to which nitrogen and hydrogen are added, and which is made of a semiconductor containing (i) polycrystalline ZnO or polycrystalline Mg_xZn_1-xO, (ii) amorphous ZnO or amorphous Mg_xZn_1-xO, or (iii) either (a) mixture of polycrystalline ZnO and amorphous ZnO or (b) mixture of polycrystalline Mg_xZn_1-xO and amorphous Mg_xZn_1-xO; and

a blocking member for blocking the active layer from an atmosphere such that the atmosphere substantially does not influence a region, in which a movable charge moves, of the active layer, wherein

said active layer includes intentionally added dopants essentially consisting of said nitrogen and said hydrogen having concentrations so that a threshold voltage of a gate voltage of the semiconductor device, when a voltage between a drain and a source region is fixed at 10V, is controlled to be substantially is in a range between 0V and 3V.

2. A method for manufacturing the semiconductor device as set forth in claim 1, comprising the step of:

forming the active layer under an atmosphere containing (i) one or more of nitrogen monoxide and nitrogen dioxide, and (ii) hydrogen peroxide.

3. The semiconductor device as set forth in claim 1, wherein:

the blocking member is made up of different blocking layers.

4. The semiconductor device as set forth in claim 3, wherein:

at least one of the blocking layers is made of SiO₂, Al₂O₃, AlN, MgO, Ta₂O₅, TiO₂, ZrO₂, stab-ZrO₂, CeO₂, K₂O, Li₂O, Na₂O, Rb₂₀, In₂O₃, La₂O₃, Sc₂O₃, Y₂O₃, KNbO₃, KTaO₃, BaTiO₃, CaSnO₃, CaZrO₃, CdSnO₃, SrHfO₃, SrSnO₃, SrTiO₃, YScO₃, CaHfO₃, MgCeO₃, SrCeO₃, BaCeO₃, SrZrO₃, BaZrO₃, LiGaO₂, (Li_1-(x+y)Na_xK_y)(Ga_1-zAl_z)O₂, or a solid solution containing at least two of them.

5. The semiconductor device as set forth in claim 4, wherein:

a blocking layer constituting the blocking layers is made of SiO₂, Al₂O₃, AlN, MgO, Ta₂O₅, TiO₂, ZrO₂, stab-ZrO₂, CeO₂, K₂O, Li₂O, Na₂O, Rb₂₀, In₂O₃, La₂O₃, Sc₂O₃, Y₂O₃, KNbO₃, KTaO₃, BaTiO₃, CaSnO₃, CaZrO₃, CdSnO₃, SrHfO₃, SrSnO₃, SrTiO₃, YScO₃, CaHfO₃, MgCeO₃, SrCeO₃, BaCeO₃, SrZrO₃, BaZrO₃, LiGaO₂, (Li_1-(x+y)Na_xK_y)(Ga_1-zAl_z)O₂, or a solid solution containing at least two of them, and

said blocking layer is so provided as to meet the active layer separately from (i) each of two electrodes serving as blocking layers and connected to the active layer, and (ii) an insulating layer, which serves as a blocking layer and meets the active layer, for insulating the active layer from a control electrode for controlling move of a movable electric charge in the active layer.

6. The semiconductor device as set forth in claim 3, wherein:

at least one of the blocking layers is made of resin.

7. The semiconductor device as set forth in claim 6, wherein:

a blocking layer constituting the blocking layers is made of resin, and

said blocking layer is so provided as to meet the active layer separately from (i) each of two electrodes serving as blocking layers and connected to the active layer, and (ii) an insulating layer, which serves as a blocking layer and meets the active layer, for insulating the active layer from a control electrode for controlling move of a movable electric charge in the active layer.

8. The semiconductor device as set forth in claim 3, further comprising:

a gate electrode for controlling move of a movable electric charge in the active layer;

a gate insulating layer, which serves as a blocking layer, for insulating the active layer from the gate electrode;

a source electrode connected to the active layer; and

a drain electrode connected to the active layer,

wherein;

at least one of the blocking layers is made of SiO₂, Al₂O₃, AlN, MgO, Ta₂O₅, TiO₂, ZrO₂, stab-ZrO₂, CeO₂, K₂O, Li₂O, Na₂O, Rb₂₀, In₂O₃, La₂O₃, Sc₂O₃, Y₂O₃, KNbO₃, KTaO₃, BaTiO₃, CaSnO₃, CaZrO₃, CdSnO₃, SrHfO₃, SrSnO₃, SrTiO₃, YScO₃, CaHfO₃, MgCeO₃, SrCeO₃, BaCeO₃, SrZrO₃, BaZrO₃, LiGaO₂, a mixed crystal of LiGaO₂ such as (Li_1-(x+y)Na_xK_y)(Ga_1-zAl_z)O₂, or a solid solution containing at least two of them.

9. The semiconductor device as set forth in claim 8, wherein:

a blocking layer constituting the blocking layers is made of SiO₂, Al₂O₃, AlN, MgO, Ta₂O₅, TiO₂, ZrO₂, stab-ZrO₂, CeO₂, K₂O, Li₂O, Na₂O, Rb₂₀, In₂O₃, La₂O₃, Sc₂O₃, Y₂O₃, KNbO₃, KTaO₃, BaTiO₃, CaSnO₃, CaZrO₃, CdSnO₃, SrHfO₃, SrSnO₃, SrTiO₃, YScO₃, CaHfO₃, MgCeO₃, SrCeO₃, BaCeO₃, SrZrO₃, BaZrO₃, LiGaO₂, (Li_{1-(x+y) Nax}K_y)(Ga_1-zAl_z)O₂, or a solid solution containing at least two of them, and

said blocking layer is so provided as to meet the active layer separately from the source electrode, the drain electrode, and the gate insulating layer, each of which serves as a blocking layer.

10. The semiconductor device as set forth in claim 3, further comprising:

a gate electrode for controlling move of a movable electric charge in the active layer;

a gate insulating layer, which serves as a blocking layer, for insulating the active layer from the gate electrode;

a source electrode connected to the active layer; and

a drain electrode connected to the active layer,

wherein;

at least one of the blocking layers is made of a resin.

11. The semiconductor device as set forth in claim 10, wherein:

a blocking layer constituting the blocking layers is made of a resin, and

said blocking layer is so provided as to meet the active layer separately from the source electrode, the drain electrode, and the gate insulating layer, each of which serves as a blocking layer.

12. An electronic device, comprising, as a switching element, the semiconductor device as set forth in claim 1.

13. The electronic device as set forth in claim 12, wherein:

the switching element is connected to a picture element electrode such that an image signal is written in or read out from the picture element electrode.

14. An electronic device, comprising, as a switching element, the semiconductor device as set forth in claim 3.

15. The electronic device as set forth in claim 14, wherein:

the switching element is connected to a picture element electrode such that an image signal is written in or read out from the picture element electrode.

16. An electronic device, comprising, as a switching element, the semiconductor device as set forth in claim 4.

17. The electronic device as set forth in claim 16, wherein:

the switching element is connected to a picture element electrode such that an image signal is written in or read out from the picture element electrode.

18. An electronic device, comprising, as a switching element, the semiconductor device as set forth in claim 5.

19. The electronic device as set forth in claim 18, wherein:

the switching element is connected to a picture element electrode such that an image signal is written in or read out from the picture element electrode.

20. An electronic device, comprising, as a switching element, the semiconductor device as set forth in claim 6.

21. The electronic device as set forth in claim 20, wherein:

the switching element is connected to a picture element electrode such that an image signal is written in or read out from the picture element electrode.

22. An electronic device, comprising, as a switching element, the semiconductor device as set forth in claim 7.

23. The electronic device as set forth in claim 22, wherein:

the switching element is connected to a picture element electrode such that an image signal is written in or read out from the picture element electrode.

24. An electronic device, comprising, as a switching element, the semiconductor device as set forth in claim 8.

25. The electronic device as set forth in claim 24, wherein:

the switching element is connected to a picture element electrode such that an image signal is written in or read out from the picture element electrode.

26. An electronic device, comprising, as a switching element, the semiconductor device as set forth in claim 9.

27. The electronic device as set forth in claim 26, wherein:

the switching element is connected to a picture element electrode such that an image signal is written in or read out from the picture element electrode.

28. An electronic device, comprising, as a switching element, the semiconductor device as set forth in claim 10.

29. The electronic device as set forth in claim 28, wherein:

the switching element is connected to a picture element electrode such that an image signal is written in or read out from the picture element electrode.

30. An electronic device, comprising, as a switching element, the semiconductor device as set forth in claim 11.

31. The electronic device as set forth in claim 30, wherein:

the switching element is connected to a picture element electrode such that an image signal is written in or read out from the picture element electrode.