CHEMICAL VAPOR DEPOSITION COLORED DIAMOND
Chemical vapor deposition grown diamonds may be provided with one or more layers of doping to form colored diamonds. In one embodiment, layers of pink colored diamond may be formed by doping with nitrogen. In further embodiments, layers of yellow colored diamond may be formed by doping with boron. In some embodiments, the grown diamond has a single crystalline structure with minimal to no grain boundaries.
1 . A method of forming a colored diamond, the method comprising:
growing alternating layers of diamond with high and low nitrogen doping using chemical vapor deposition, such that at least some of the high nitrogen doped layers are internal to the grown diamond.
2 . The method of claim 1 wherein the high nitrogen doping is in the range of 0.1 to 10 ppm.
3 . The method of claim 1 wherein the nitrogen doped layers have a thickness in the range of 1 um to 1 mm.
4 . The method of claim 1 wherein three or more high doped layers are formed.
5 . The method of claim 1 wherein the diamond is grown as a plate that can be cut into gemstones, and wherein the gemstones have tables and doped layers substantially parallel to the <100> plane.
6 . The method of claim 1 and further comprising irradiating the high doped layers.
7 . The method of claim 1 and further comprising annealing one or more high doped layers.
8 . The method of claim 7 wherein the annealing is performed at temperatures between 700 and 1000° C.
9 . The method of claim 8 wherein the annealing is performed for approximately 30 minutes to an hour.
10 . The method of claim 7 wherein the annealing is performed at a temperature of approximately 1700° C. or higher.
11 . The method of claim 10 wherein the annealing is performed in a vacuum, inert atmosphere, or hydrogen plasma.
12 . A method of forming a colored diamond, the method comprising:
growing alternating layers of diamond with high and low boron doping using chemical vapor deposition, such that at least some of the high boron doped layers are internal to the grown diamond.
13 . The method of claim 12 and further comprising including at least one nitrogen doped layer in the grown diamond and annealing one or more of the nitrogen doped layers.
14 . The method of claim 13 wherein the annealing is performed at temperatures between 700 and 1000° C.
15 . The method of claim 13 wherein the annealing is performed at a temperature of approximately 1700° C. or higher.
16 . The method of claim 15 wherein the annealing is performed in a vacuum, inert atmosphere, or hydrogen plasma.
17 . A method of forming a colored diamond, the method comprising:
growing alternating layers of diamond with high and low nitrogen doping using chemical vapor deposition, such that at least some of the high nitrogen doped layers are internal to the grown diamond; and
further growing layers of diamond with high boron doping between one or more of the high and low nitrogen doped layers.
18 . The method of claim 17 wherein the colored diamond is green.
19 . The method of claim 17 wherein the colored diamond is purple.
20 . The method of claim 17 and further comprising:
irradiating one or more of the nitrogen doped layers; and
annealing one or more of the nitrogen doped layers to change the color of such layers.