Semiconductor device including active layer of zinc oxide with controlled crystal lattice spacing and manufacturing method thereof

• US 20070278490A1
• Filed: 06/01/2007
• Published: 12/06/2007
• Est. Priority Date: 06/02/2006
• Status: Active Grant

• Current Assignee: Casio Computer Company Limited, Kochi Industrial Promotion Center
• Original Assignee: Casio Computer Company Limited, Kochi Industrial Promotion Center
• Inventors: Furuta, Hiroshi, Hirao, Takashi, Matsuda, Tokiyoshi, Hiramatsu, Takahiro, Furuta, Mamoru
• Granted Patent: US 7,598,520 B2
• Time in Patent Office: Days
• US Class Current: 257/64
• CPC Class Codes: H01L 29/04 characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes characterised by physical imperfections H01L29/30
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes
• CPC Class Codes: H01L 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• 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

A semiconductor device includes an oxide semiconductor thin film layer of zinc oxide. The (002) lattice planes of at least a part of the oxide semiconductor thin film layer have a preferred orientation along a direction perpendicular to a substrate of the semiconductor device and a lattice spacing d₀₀₂ of at least 2.619 Å.

Claims

1. A semiconductor device comprising:

a substrate; and

a semiconductor element including an oxide semiconductor thin film layer of zinc oxide, which is formed on the substrate, and at least a portion of which includes (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

.

2. The semiconductor device according to claim 1, wherein the entire oxide semiconductor thin film layer includes (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

.

3. The semiconductor device according to claim 1, wherein a portion of the oxide semiconductor thin film layer which is in contact with the substrate includes (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

.

4. The semiconductor device according to claim 1, wherein the lattice spacing d₀₀₂ of the (002) lattice planes of the oxide semiconductor thin film layer is at least 2.625 Å

.

5. The semiconductor device according to claim 1, further comprising an insulating film formed on the oxide semiconductor thin film layer.

6. The semiconductor device according to claim 1, wherein the semiconductor element comprises a thin film transistor.

7. A semiconductor device comprising:

a substrate;

an oxide semiconductor thin film layer of zinc oxides which is formed on the substrate, and at least a portion of which includes (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

; and

contact layers of zinc oxide, which are formed in contact with the oxide semiconductor thin film layer, and at least a portion of each of which includes (002) lattice planes having a preferred orientation along the direction perpendicular to the substrate and a lattice spacing d₀₀₂ that is smaller than the lattice spacing d₀₀₂ of the (002) lattice planes of the oxide semiconductor thin film layer.

8. The semiconductor device according to claim 7, wherein the entire oxide semiconductor thin film layer and the entire contact layers include (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

.

9. The semiconductor device according to claim 7, wherein a portion of the oxide semiconductor thin film layer which is in contact with the substrate and a portion of the contact layers which is in contact with the substrate include (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

.

10. The semiconductor device according to claim 7, wherein the lattice spacing d₀₀₂ of the (002) lattice planes of the contact layers is not more than 2.605 Å

.

11. The semiconductor device according to claim 7, wherein the lattice spacing d₀₀₂ of the (002) lattice planes of the oxide semiconductor thin film layer is at least 2.625 Å

, and the lattice spacing d₀₀₂ of the (002) lattice planes of the contact layers is not more than 2.619 Å

.

12. The semiconductor device according to claim 11, wherein the lattice spacing d₀₀₂ of the (002) lattice planes of the contact layers is not more than 2.605 Å

.

13. The semiconductor device according to claim 7, further comprising:

a pair of source/drain electrodes electrically coupled to the oxide semiconductor thin film layer via the contact layers;

a gate insulator; and

a gate electrode formed on the gate insulator;

wherein the oxide semiconductor thin film layer, the contact layers, the pair of the source/drain electrodes, the gate insulator, and the gate electrode constitute a thin film transistor.

14. A semiconductor device comprising:

a substrate; and

an oxide semiconductor thin film layer of zinc oxide which is formed on the substrate, and at least a portion of which includes (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

;

wherein the oxide semiconductor thin film layer includes a first region of intrinsic zinc oxide and second regions of zinc oxide doped with ions acting as donors to zinc oxide, and

wherein the second regions have a lower resistance than a resistance of the first regions.

15. The semiconductor device according to claim 14, wherein the entire oxide semiconductor thin film layer includes (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

.

16. The semiconductor device according to claim 14, wherein a portion of the oxide semiconductor thin film layer which is in contact with the substrate includes (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

.

17. The semiconductor device according to claim 14, wherein the lattice spacing d₀₀₂ of the (002) lattice planes of the oxide semiconductor thin film layer is at least 2.625 Å

.

18. The semiconductor device according to claim 14, further comprising:

a pair of source/drain electrodes electrically coupled to the second regions of the oxide semiconductor thin film layer;

a gate insulator; and

a gate electrode formed on the gate insulator to lie over the first region of the oxide semiconductor thin film layer via the gate insulator;

wherein the oxide semiconductor thin film layer, the pair of the source/drain electrodes, the gate insulator and the gate electrode constitute a thin film transistor.

19. The semiconductor device according to claim 14, wherein the ions acting as donors to zinc oxide are obtained by ionizing at least one group III element.

20. A manufacturing method of a semiconductor device comprising:

providing a substrate; and

depositing an oxide semiconductor thin film layer of zinc oxide on the substrate, such that at least a portion of the oxide semiconductor thin film layer in an as-deposited state includes (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

.

21. The manufacturing method of a semiconductor device according to claim 20, wherein the entire oxide semiconductor thin film layer in the as-deposited state includes (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

.

22. The manufacturing method of a semiconductor device according to claim 20, wherein a portion of the oxide semiconductor thin film layer in the as-deposited state which is in contact with the substrate includes (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

.

23. The manufacturing method of a semiconductor device according to claim 20, wherein the lattice spacing d₀₀₂ of the (002) lattice planes of the oxide semiconductor thin film layer in the as-deposited state is at least 2.625 Å

.

24. A manufacturing method of a semiconductor device comprising:

providing a substrate;

depositing an oxide semiconductor thin film layer of zinc oxide, such that at least a portion of the oxide semiconductor thin film layer in an as-deposited state includes (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

; and

depositing contact layers to be in contact with the oxide semiconductor thin film layer, such that at least a portion of each of the contact layers in an as-deposited state includes (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing d₀₀₂ that is smaller than the lattice spacing d₀₀₂ of the (002) planes of the oxide semiconductor thin film layer.

25. The manufacturing method of a semiconductor device according to claim 24, wherein the entire oxide semiconductor thin film layer and the entire contact layers, which are both in the as-deposited state, include (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

.

26. The manufacturing method of a semiconductor device according to claim 24, wherein a portion of the oxide semiconductor thin film layer in the as-deposited state which is in contact with the substrate and a portion of the contact layers in the as-deposited state which is in contact with the substrate include (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

.

27. The manufacturing method of a semiconductor device according to claim 24, wherein the lattice spacing d₀₀₂ of the (002) lattice planes of the contact layers in the as-deposited state is not more than 2.605 Å

.

28. The manufacturing method of a semiconductor device according to claim 24, wherein the lattice spacing d₀₀₂ of the (002) lattice planes of the oxide semiconductor thin film layer in the as-deposited state is at least 2.625 Å

, and the lattice spacing d₀₀₂ of the (002) lattice planes of the contact layers in the as-deposited state is not more than 2.619 Å

.

29. The manufacturing method of a semiconductor device according to claim 28, wherein the lattice spacing d₀₀₂ of the (002) lattice planes of the contact layers in the as-deposited state is not more than 2.605 Å

.

30. A manufacturing method of a semiconductor device comprising:

providing a substrate;

depositing, on the substrate, an oxide semiconductor thin film layer of zinc oxide, such that at least a portion of the oxide semiconductor thin film layer in an as-deposited state includes (002) lattice planes having a preferred orientation along a direction perpendicular to the substrate and a lattice spacing of at least 2.619 Å

;

doping a plurality of regions of the oxide semiconductor thin film layer with ions that act as donors to zinc oxide to form second regions which are doped with the ions, such that a first region of the oxide semiconductor thin film layer is defined as a region other than the second regions; and

subjecting the second regions to an activation treatment.

31. The manufacturing method of a semiconductor device according to claim 30, wherein the entire oxide semiconductor thin film layer in the as-deposited state includes (002) lattice planes having a preferred orientation along the direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

.

32. The manufacturing method of a semiconductor device according to claim 30, wherein a portion of the oxide semiconductor thin film layer in the as-deposited state which is in contact with the substrate includes (002) lattice planes having a preferred orientation along the direction perpendicular to the substrate and a lattice spacing d₀₀₂ of at least 2.619 Å

.

33. The manufacturing method of a semiconductor device according to claim 30, wherein the activation treatment includes a heat treatment.

34. The manufacturing method of a semiconductor device according to claim 30, wherein the lattice spacing d₀₀₂ of the (002) lattice planes of the oxide semiconductor thin film layer in the as-deposited state is at least 2.625 Å

.

35. The manufacturing method of a semiconductor device according to claim 30, further comprising:

forming source/drain electrodes coupled to the oxide semiconductor thin film layer;

forming a gate insulator; and

forming a gate electrode on the gate insulator;

wherein the oxide semiconductor thin film layer, the source/drain electrodes, the gate insulator and the gate electrode function as a thin film transistor in which the first region of the oxide semiconductor thin film layer functions as a channel.

36. The manufacturing method of a semiconductor device according to claim 35, further comprising uncovering the second regions of the oxide semiconductor thin film layer by removing the gate insulator from the second regions of the oxide semiconductor thin film layer using the gate electrode as a mask.

37. The manufacturing method of a semiconductor device according to claim 36, wherein the doping of the oxide semiconductor thin film layer with the ions that act as donors to zinc oxide to form the second regions is performed after the uncovering of the second regions of the oxide semiconductor thin film layer.

38. The manufacturing method of a semiconductor device according to claim 36, wherein the activation treatment is performed by forming an insulating film on the uncovered second regions.

39. The manufacturing method of a semiconductor device according to claim 30, wherein the doping of at least a part of the second regions of the oxide semiconductor thin film layer is performed using ions obtained by ionizing at least one group III element.