Transparent nanocrystalline diamond coatings and devices
A method for coating a substrate comprises producing a plasma ball using a microwave plasma source in the presence of a mixture of gases. The plasma ball has a diameter. The plasma ball is disposed at a first distance from the substrate and the substrate is maintained at a first temperature. The plasma ball is maintained at the first distance from the substrate, and a diamond coating is deposited on the substrate. The diamond coating has a thickness. Furthermore, the diamond coating has an optical transparency of greater than about 80%. The diamond coating can include nanocrystalline diamond. The microwave plasma source can have a frequency of about 915 MHz.
1. A method for forming a transparent semi-conductor device, comprising:
producing a plasma ball using a microwave plasma source in the presence of a mixture of gases, the plasma ball having a diameter;
disposing the plasma ball at a first distance from a substrate, the substrate maintained at a first temperature;
maintaining the plasma ball at the first distance from the substrate for a first time;
depositing a nanocrystalline diamond film on the substrate, the nanocrystalline diamond film having a thickness, the nanocrystalline diamond film having a transparency of greater than about 80 percent;
doping the nanocrystalline diamond film with at least one of a p-type dopant and a n-type dopant; and
annealing the substrate with the nanocrystalline diamond film disposed thereon at a second temperature for a second time.
2. The method of claim 1 , wherein a frequency of the microwave plasma source is about 915 MHz.
3. The method of claim 1 , wherein the diameter of the plasma ball is about 15 cms to about 30 cms.
4. The method of claim 1 , wherein the mixture of gases includes argon, methane and hydrogen.
5. The method of claim 1 , wherein the first temperature is in the range of about 200 degrees Celsius to about 450 degrees Celsius.
6. The method of claim 1 , wherein the thickness of the nanocrystalline diamond film is in the range of about 30 nm to about 150 nm.
7. The method of claim 1 , wherein the second temperature is about 800 degrees Celsius to about 1,200 degrees Celsius.
8. The method of claim 1 , wherein the second time is less than about 20 seconds.
9. The method of claim 1 , wherein the substrate includes at least one of silicon oxide, glass, quartz, indium tin oxide, aluminum oxide, magnesium oxide and sapphire.