Field-enhanced diffusion using optical activation

• US 5,597,762 A
• Filed: 09/27/1994
• Issued: 01/28/1997
• Est. Priority Date: 09/27/1994
• Status: Expired due to Term

• Current Assignee: Nanophase Diamond Technologies, Inc.
• Original Assignee: Nonophase Diamond Technologies Incorporated
• Inventors: Prelas, Mark A., Popovici, Galina, Sung, T., Khasawinah, S.
• Primary Examiner(s): Thomas, Tom
• Assistant Examiner(s): MULPURI, SAVITRI
• Application Number:
  US08/313,641
• Time in Patent Office: 854 Days
• Field of Search: 437/160, 437/169, 437/168, 437/171, 437/173, 437/954, 437/162, 257/77, 168/DIG. 93, 168/99, 168/35
• US Class Current: 438/105
• CPC Class Codes: H01J 9/022 of cold cathodes
• CPC Class Codes: H01L 21/222 Lithium-drift
• CPC Class Codes: H01L 29/66022 the devices being controllable only by variation of the electric current supplied or the electric potential applied, to one or more of the electrodes carrying the current to be rectified, amplified, oscillated or switched, e.g. two-terminal devices
• 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

Abstract

A method of making a semiconductor material using a modified forced diffusion method includes the steps of placing the semiconductor material on a substrate in a vacuum vessel, locating an impurity atop the semiconductor material, creating a high voltage potential across the semiconductor material, heating the semiconductor material and bombarding the semiconductor material with photons under the effects of the high voltage and heat previously created. The process is particularly applicable to creating N-type diamond semiconductor material.

Claims

1. A method of making semiconductor material comprising the steps of:

(a) placing a diamond substrate material on a substrate holder in an inert atmosphere or a vacuum vessel;

(b) placing an impurity on the diamond substrate material;

(c) creating a voltage potential across the diamond substrate material;

(d) heating at least a portion of the diamond substrate material; and

(e) bombarding the diamond substrate material with photons during the execution of steps (c) and (d).

2. The method of claim 1 wherein the photon source is a laser.

3. The method of claim 2 wherein the impurity used in step (b) is of the type that creates N-type semiconductor material.

4. The method of claim 3 wherein the impurity is taken from the group lithium, oxygen, fluorine and chlorine.

5. The method of claim 2 wherein the impurity is of the type that creates P-type semiconductor material.

6. The method of claim 4 wherein the impurity is a lithium salt.

7. The method of claim 1 wherein step (d) is accomplished by heating the substrate holder.

8. The method of claim 1 wherein step (e) is accomplished by focusing a laser beam onto the impurity and moving the beam to create a desired pattern on the diamond substrate material.

9. The method of claim 3 wherein the laser is a helium-neon laser.

10. A method of making semiconductor material comprising the steps of:

(a) placing a diamond substrate material on a substrate holder in an inert atmosphere or a vacuum vessel;

(b) placing an impurity on the diamond substrate material;

(c) creating an electric field across the diamond substrate material;

(d) heating at least a portion of the diamond substrate material; and

(e) bombarding the diamond substrate material with photons during the execution of steps (c) and (d) whereby to cause atoms from the impurity to diffuse into the diamond substrate material.

11. The method of claim 10 wherein step (e) is performed by a laser.

12. The method of claim 11 wherein the impurity used in step (b) is of the type that creates N-type semiconductor material.

13. The method of claim 12 wherein the impurity is taken from the group lithium, oxygen, fluorine and chlorine.

14. The method of claim 11 wherein the impurity is of the type that creates P-type semiconductor material.

15. The method of claim 13 wherein the impurity is a lithium salt.

16. The method of claim 10 wherein step (d) is accomplished by heating the substrate holder.

17. The method of claim 10 wherein step (e) is accomplished by focusing a laser beam onto the substrate material near the impurity and moving the beam to create a desired pattern on the diamond substrate material.

18. The method of claim 12 wherein the laser is a helium-neon laser.

19. The method of claim 10 wherein a photon source is provided to perform step (e) such that the photons have an energy Ep which is greater than an activation energy Ea of the impurity.