Method of making enhanced CVD diamond

• US RE41,189 E1
• Filed: 01/30/2009
• Issued: 04/06/2010
• Est. Priority Date: 06/03/2002
• Status: Expired due to Term

• Current Assignee: Carnegie Institution of Washington
• Original Assignee: Carnegie Institution of Washington
• Inventors: Li, Wei, Yan, Chih-shiue, Mao, Ho-kwang, Hemley, Russell J.
• Primary Examiner(s): Meeks; Timothy H
• Assistant Examiner(s): BURKHART, ELIZABETH A
• Application Number:
  US12/362,529
• Time in Patent Office: 431 Days
• Field of Search: 427/249.7, 427/249.8, 427/370, 427/372.2, 427/444, 427/902, 117/88
• US Class Current: 117/88
• CPC Class Codes: C23C 16/27 Diamond only
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: C30B 29/04 Diamond
• CPC Class Codes: C30B 33/02 Heat treatment C30B33/04, C30B33/06 take precedence
• CPC Class Codes: Y10S 427/103 Diamond-like carbon coating, i.e. DLC

Abstract

Single crystal CVD diamond is heated to temperatures of 1500° C. to 2900° C. under a pressure that prevents significant graphitization. The result is a CVD diamond with improved optical properties.

Claims

1. A method to improve the optical clarity of CVD diamond where the CVD diamond is single crystal CVD diamond, by raising the CVD diamond to a set temperature of at least 1500°

C. and a pressure of at least 4.0 GPA outside of the diamond stable phase.

2. The method of claim 1 wherein the CVD diamond is a single crystal coating upon another material.

3. The method of claim 1 wherein the step of raising the temperature of the single crystal CVD diamond further comprises the step of:

raising the single crystal CVD diamond to a set temperature of about 1800°

C. to about 2900°

C.

4. The method of claim 1 wherein the step of raising the temperature of the single crystal CVD diamond further comprises the step of:

maintaining the temperature of the single crystal CVD diamond at the set temperature for less than about one minute.

5. The method of claim 1 wherein the step of raising the temperature of the single crystal CVD diamond further comprises the step of:

raising the temperature of the single crystal CVD diamond to at least 1500°

C. over a time period of about one minute to five minutes.

6. The method of claim 1 wherein the step of raising the temperature of the single crystal CVD diamond comprises of the step of:

raising the temperature of the single crystal CVD diamond to about 2200°

C. at a pressure of about 5.0 GPA.

7. The method of claim 1 further comprising the step of:

after reaching the set temperature, decreasing the temperature of the CVD diamond to ambient temperature while maintaining the pressure on the single crystal CVD diamond.