Thermochemical polishing of CVD diamond films

Grinding characteristics of diamond film using composite electro-plating in-process sharpening method

“…However, the surface roughness of a diamond film coated by the chemical vapor deposition (CVD) process increases with increasing film thickness, and its maximum value can achieve several microns [2]. Hence, the surface roughness must be decreased to meet the actual requirement from sub-microns to nanometers, but the surface machining process is time consuming and expensive [3][4][5][6][7][8][9][10][11][12].…”

“…In the mechanical polishing method [3,4], the polishing is accomplished by reciprocating the specimen under the diamond wheel. In the thermo-chemical polishing method, the diamond film is polished using iron or nickel plate at high temperature (higher than 700 1C) so that the carbon atoms on the diamond film can be diffused into the plate, thus polishing the surface [5][6][7]. In the chemo-mechanical polishing method, potassium nitrate (KNO 3 ) or potassium permanganate (KMnO 4 ) is used as an oxidizing agent and a ceramic plate or diamond film as the polisher.…”

Low energy carbonaceous and graphite phases on the surfaces of thermochemically polished chemical vapor deposited diamond films

“…Confocal Raman spectroscopy had revealed that thermochemically polished surfaces do not exhibit any shift of the Raman line from its original position at approximately 1332 cm Ϫ1 . 1,6 This shows that the thermochemical polishing method does not distort the lattice structure of the surfaces of the films after polishing. The mechanism of thermochemical polishing has been described in detail by previous researchers.…”

“…1 This ultrasmooth polishing is essential for the application of chemical vapor deposited ͑CVD͒ diamond films in areas of electronics such as heat management, optical windows etc. For instance, smooth polishing ensures firm electrical contacts to diamond and it can tremendously cut down the thermal resistance at the interface of the diamond heat spreader.…”

“…The thermochemical polishing method is particularly suitable for treating polycrystalline CVD diamond films which are difficult to polish using conventional methods. [1][2][3][4][5] The difficulty encountered by conventional methods is a consequence of the random orientation of the crystallites that build up the films. Conventional methods such as mechanical polishing 5 are very sensitive to directional and planar random orientations of the polished diamond film with respect to the polishing direction.…”