DIAMOND SEMICONDUCTOR ELEMENT AND PROCESS FOR PRODUCING THE SAME

• US 20080134959A1
• Filed: 01/31/2008
• Published: 06/12/2008
• Est. Priority Date: 06/20/2005
• Status: Abandoned Application

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: Yamauchi, Yoshiharu, Ueda, Kenji, Makimoto, Toshiki, Kasu, Makoto
• Application Number:
  US12/023,631
• Publication Number:
  US 20080134959A1
• Time in Patent Office: Days
• US Class Current: 117/84
• CPC Class Codes: C23C 16/274 using microwave discharges
• CPC Class Codes: C23C 16/278 doping or introduction of a secondary phase in the diamond
• CPC Class Codes: C30B 25/105 by irradiation or electric discharge
• CPC Class Codes: C30B 29/04 Diamond
• CPC Class Codes: C30B 33/02 Heat treatment C30B33/04, C30B33/06 take precedence
• CPC Class Codes: C30B 33/06 Joining of crystals
• CPC Class Codes: H01L 21/02013 Grinding, lapping
• CPC Class Codes: H01L 21/02027 Setting crystal orientation
• CPC Class Codes: H01L 21/02376 Carbon, e.g. diamond-like carbon
• CPC Class Codes: H01L 21/02433 Crystal orientation
• CPC Class Codes: H01L 21/02527 Carbon, e.g. diamond-like carbon
• CPC Class Codes: H01L 21/02579 P-type
• CPC Class Codes: H01L 21/02609 Crystal orientation
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/0405 the devices having semiconductor bodies comprising semiconducting carbon, e.g. diamond, diamond-like carbon multistep processes for the manufacture of said devices H01L29/66015
• CPC Class Codes: H01L 21/0415 using ion implantation
• CPC Class Codes: H01L 21/324 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/20 - H01L21/288 and H01L21/302 - H01L21/322 take precedence
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes
• CPC Class Codes: H01L 29/1602 Diamond
• CPC Class Codes: H01L 29/45 Ohmic electrodes
• CPC Class Codes: H01L 29/66037 : the devices being controllable only by the electric current supplied or the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched, e.g. three-terminal devices
• CPC Class Codes: H01L 29/66045 : Field-effect transistors
• CPC Class Codes: H01L 29/66742 : Thin film unipolar transistors
• CPC Class Codes: H01L 29/66856 : with an active layer made of a group 13/15 material H01L29/66446 takes precedence
• CPC Class Codes: H01L 29/732 : Vertical transistors
• CPC Class Codes: H01L 29/78 : with field effect produced by an insulated gate H01L29/7725, H01L29/775, H01L29/778 take precedence
• CPC Class Codes: H01L 29/78684 : having a semiconductor body comprising semiconductor materials of Group IV not being silicon, or alloys including an element of the group IV, e.g. Ge, SiN alloys, SiC alloys H01L29/7869 takes precedence
• CPC Class Codes: H01L 29/812 : with a Schottky gate H01L29/7725, H01L29/775, H01L29/778, H01L29/806 take precedence; with Schottky contact on top of heterojunction gate H01L29/802
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/0054 : for devices with an active region comprising only group IV elements

Abstract

An integrated optical waveguide has a first optical waveguide, a second optical waveguide, and a groove. The second optical waveguide is coupled to the first optical waveguide and has a refractive index that is different from the first optical waveguide. The groove is disposed so as to traverse an optical path of the first optical waveguide and is separated from an interface between the first optical waveguide and the second optical waveguide by a predetermined spacing. The spacing from the interface and the width of the groove are determined such that reflection at a boundary between the first optical waveguide and the second optical waveguide is weakened. A semiconductor board may be disposed at a boundary between the first optical waveguide and the second optical waveguide. In this case, the width of the groove and the thickness of the semiconductor board are determined such that light reflected off an interface between the first optical waveguide and the groove is weakened by light reflected from an interface between the groove and the semiconductor board, and by light reflected from an interface between the semiconductor board and the second optical waveguide.

Claims

1. A p-type diamond semiconductor, comprising, as a dopant element, any of the elements, Al, Be, Ca, Cd, Ga, In, Li, Mg and Zn.

2. The p-type diamond semiconductor according to claim 1, wherein the concentration of said dopant element is a concentration enabling a hole concentration in said p-type diamond semiconductor to be no less than 1.0×

10¹⁵ cm<sup>−

3</sup> and also to be no more than 1.0×

10²¹ cm<sup>−

3</sup> at each temperature.

3. The p-type diamond semiconductor according to claim 1, comprising Al as said dopant element in a concentration of no less than 2.6×

10¹⁶ cm<sup>−

3</sup> and no more than 1.0×

10²¹ m<sup>−

3</sup>.

4. The p-type diamond semiconductor according to claim 1, comprising Be as said dopant element in a concentration of no less than 1.3×

10¹⁶ cm<sup>−

3</sup> and no more than 1.0×

10²¹ cm<sup>−

3</sup>.

5. The p-type diamond semiconductor according to claim 1, comprising Ca as said dopant element in a concentration of no less than 3.2×

10¹⁶ cm<sup>−

3</sup> and no more than 1.0×

10²¹ cm<sup>−

3</sup>.

6. The p-type diamond semiconductor according to claim 1, comprising Cd as said dopant element in a concentration of no less than 6.4×

10¹⁵ cm<sup>−

3</sup> and no more than 1.0×

10²¹ cm<sup>−

3</sup>.

7. The p-type diamond semiconductor according to claim 1, comprising Ga as said dopant element in a concentration of no less than 8.1×

10¹⁵ cm<sup>−

3</sup> and no more than 1.0×

10²¹ cm<sup>−

3</sup>.

8. The p-type diamond semiconductor according to claim 1, comprising In as t element in a concentration of no less than 5.1×

10¹⁵ cm<sup>−

3</sup> and no more than 1.0×

10²¹ cm<sup>−

3</sup>.

9. The p-type diamond semiconductor according to claim 1, comprising Li as said dopant element in a concentration of no less than 3.2×

10¹⁶ cm<sup>−

3</sup> and no more than 1.0×

10²¹ cm<sup>−

3</sup>.

10. The p-type diamond semiconductor according to claim 1, comprising Mg as said dopant element in a concentration of no less than 1.0×

10¹⁷ cm<sup>−

3</sup> and no more than 1.0×

10²¹ cm<sup>−

3</sup>.

11. The p-type diamond semiconductor according to claim 1, comprising Zn as said dopant element in a concentration of no less than 1.6×

10¹⁶ cm<sup>−

3</sup> and no more than 1.0×

10²¹ cm<sup>−

3</sup>.

32. An MESFET, comprising:

a diamond substrate;

the p-type diamond semiconductor layer, described in claim 1, formed on said diamond substrate;

a source electrode and a drain electrode formed on said p-type diamond semiconductor layer at a distance from each other; and

a gate electrode formed between said source electrode and drain electrode on said p-type diamond semiconductor layer.

33. An MISFET, comprising:

a diamond substrate;

the p-type diamond semiconductor layer, described in claim 1, formed on said diamond substrate;

a source electrode and a drain electrode formed on said p-type diamond semiconductor layer at a distance from each other;

an insulating layer formed between said metal electrodes on said p-type diamond semiconductor layer; and

a gate electrode formed on said insulating layer.

34. An npn-type bipolar transistor, comprising:

a diamond substrate;

a first n-type diamond semiconductor layer formed on said diamond substrate;

the first p-type diamond semiconductor layer, described in claim 1, and a first metal electrode that are formed on said first n-type diamond semiconductor layer at a distance from each other;

a second n-type diamond semiconductor layer and a second metal electrode that are formed on said p-type diamond semiconductor layer at a distance from each other; and

a third metal electrode formed on said second n-type diamond semiconductor layer.

35. A pnp-type bipolar transistor, comprising:

a diamond substrate;

the first p-type diamond semiconductor layer, described in claim 1, formed on said diamond substrate;

an n-type diamond semiconductor layer and a first electrode that are formed on said first p-type diamond semiconductor layer at a distance from each other;

the second p-type diamond semiconductor layer, described in claim 1 and formed on said diamond substrate, and a second electrode that are formed on said n-type diamond semiconductor layer at a distance from each other; and

a third electrode formed on said second p-type diamond semiconductor layer.

36. An LED, comprising:

a diamond substrate;

the p-type diamond semiconductor layer, described in claim 1, formed on said diamond substrate;

an n-type diamond semiconductor layer and an anode electrode that are formed on said p-type diamond semiconductor layer at a distance from each other;

a cathode electrode formed on said n-type diamond semiconductor layer.

12. A process for producing a p-type diamond semiconductor, wherein a diamond is doped with any of the elements Al, Be, Ca, Cd, Ga, In, Li, Mg and Zn by ultra-high-temperature and high-pressure synthesis.

13. A process for producing a p-type diamond semiconductor, wherein a diamond is doped with any of elements Al, Be, Ca, Cd, Ga, In, Li, Mg and Zn by ion implantation.

14. A process for producing a p-type diamond semiconductor, wherein a p-type diamond semiconductor film is grown, by a chemical vapor deposition (CVD) technique, on a diamond substrate from a source gas including, at least, a gas that includes carbon (C) and a dopant gas in which the ratio of the number of Al atoms to the number of C atoms (Al/C) is no less than 0.26 ppm and no more than 10⁴ ppm.

15. The process of producing a p-type diamond semiconductor according to claim 14, wherein said Al dopant gas includes any of the following four:

aluminum (Al) vaporized by introducing solid-state Al into plasma, trimethylaluminum ((CH₃)₃Al;

TMAl), triethylaluminum ((C₂H₅)₃Al;

TEAl) and aluminium chloride (AlCl₃).

16. A process of producing a p-type diamond semiconductor, wherein a p-type diamond semiconductor film is grown, by a chemical vapor deposition (CVD) technique, on a diamond substrate from a source gas including, at least, a gas that includes carbon (C) and a dopant gas in which the ratio of the number of Be atoms to the number of C atoms (Be/C) is no less than 0.13 ppm and no more than 10⁴ ppm.

17. The process of producing a p-type diamond semiconductor according to claim 16, wherein said Be dopant gas includes beryllium (Be) vaporized by introducing solid-state Be into plasma.

18. A process of producing a p-type diamond semiconductor, wherein a p-type diamond semiconductor film is grown, by a chemical vapor deposition (CVD) technique, on a diamond substrate from a source gas including, at least, a gas that includes carbon (C) and a dopant gas in which the ratio of the number of Ca atoms to the number of C atoms (Ca/C) is no less than 0.32 ppm and no more than 10⁴ ppm.

19. The process of producing a p-type diamond semiconductor according to claim 18, wherein said Ca dopant gas includes either calcium (Ca) vaporized by introducing solid-state Ca into plasma, or calcium chloride (CaCl₂).

20. A process for producing a p-type diamond semiconductor, wherein a p-type diamond semiconductor film is grown, by a chemical vapor deposition (CVD) technique, on a diamond substrate from a source gas including, at least, a gas that includes carbon (C) and a dopant gas in which the ratio of the number of Cd atoms to the number of C atoms (Cd/C) is no less than 0.064 ppm and no more than 1 ppm.

21. The process of producing a p-type diamond semiconductor according to claim 20, wherein said Cd dopant gas includes any of the following three:

dimethylcadmium ((CH₃)₂Cd;

DMCd), diethylcadmium ((C₂H₅)₂Cd;

DECd) and cadmium chloride (CdCl₂).

22. A process for producing a p-type diamond semiconductor, wherein a p-type diamond semiconductor film is grown, by a chemical vapor deposition (CVD) technique, on a diamond substrate from a source gas including, at least, a gas that includes carbon (C) and a dopant gas in which the ratio of the number of Ga atoms to the number of C atoms (Ga/C) is no less than 0.081 ppm and no more than 10⁴ ppm.

23. The process of producing a p-type diamond semiconductor according to claim 22, wherein said Ga dopant gas includes any of the following three:

trimethylgallium ((CH₃)₃Ga;

TMGa), triethylgallium ((C₂H₅)₃Ga;

TEGa) and gallium chloride (GaCl₃).

24. A process for producing a p-type diamond semiconductor, wherein a p-type diamond semiconductor film is grown, by a chemical vapor deposition (CVD) technique, on a diamond substrate from a source gas including, at least, a gas that includes carbon (C) and a dopant gas in which the ratio of the number of In atoms to the number of C atoms (In/C) is no less than 0.051 ppm and no more than 10⁴ ppm.

25. The process of producing a p-type diamond semiconductor according to claim 24, wherein said In dopant gas includes any of the following three:

trimethylindium ((CH₃)₃In;

TMIn), triethylindium ((C₂H₅)₃In;

TEIn) and indium chloride (InCl₃).

26. A process for producing a p-type diamond semiconductor, wherein a p-type diamond semiconductor film is grown, by a chemical vapor deposition (CVD) technique, on a diamond substrate from a source gas including, at least, a gas that includes carbon (C) and a dopant gas in which the ratio of the number of Li atoms to the number of C atoms (Li/C) is no less than 3.0 ppm and no more than 10⁴ ppm.

27. The process of producing a p-type diamond semiconductor according to claim 26, wherein said Li dopant gas includes any of the following three:

methyllithium (CH₃Li), ethyllithium (C₂H₅Li) and propyllithium (C₃H₇Li).

28. A process for producing a p-type diamond semiconductor, wherein a p-type diamond semiconductor film is grown, by a chemical vapor deposition (CVD) technique, on a diamond substrate from a source gas including, at least, a gas that includes carbon (C) and a dopant gas in which the ratio of the number of Mg atoms to the number of C atoms (Mg/C) is no less than 1.0 ppm and no more than 10⁴ ppm.

29. The process of producing a p-type diamond semiconductor according to claim 28, wherein said dopant gas including Mg includes any of the following three:

bis-cyclopentadienyl magnesium ((C₅H₅)₂Mg;

Cp₂Mg), bis-methylcyclopentadienyl magnesium ((CH₃C₅H₄)₂Mg;

MCp₂Mg) and magnesium chloride (MgCl₂).

30. A process for producing a p-type diamond semiconductor, wherein a p-type diamond semiconductor film is grown, by a chemical vapor deposition (CVD) technique, on a diamond substrate from a source gas including, at least, a gas that includes carbon (C) and a dopant gas in which the ratio of the number of Zn atoms to the number of C atoms (Zn/C) is no less than 0.16 ppm and no more than 10⁴ ppm.

31. The process of producing a p-type diamond semiconductor according to claim 30, wherein said dopant gas including Zn includes any of the following three:

dimethylzinc ((CH₃)₂Zn;

DMZn), diethylzinc ((C₂H₅)₂Zn;

DEZn) and zinc chloride (ZnCl₂).