Study On The Preparation And Properties Of Films System On Diamond For IR Anti-reflection And Anti-oxidation

Diamond has excellent properties such as good transmittance in the infrared wave band, low absorption coefficient, high resistance to thermal shock and friction. Diamond is an ideal material for airborne windows and domes of high-speed flight aircraft. However, diamond is easily subject to oxidation in air at temperatures greater than 750°C, and the optical transmittance is degraded greatly. In order to meet the need for applications of high-speed or high-temperature environment, the anti-oxidation and anti-reflective films must be prepared on the diamond surface. Aluminum nitride (AlN) is a promising anti-oxidation material with good physical, chemical properties and good anti-oxidation property. Researches of this paper mostly concentrate on preparation of AlN films and the functions of experiment parameters on films structure and optical properties and high temperature anti-oxidation properties etc.1. Al/Si//Diamond and AlN/Ge//Diamond antireflection films systems are designed by the software of OPFCAD. Results show that the transmittance of the film system in infrared wave band are exceed 90%, and meet the need of high infrared windows and domes in execrable environment.2. The influence of main parameters on deposition rate is discussed. The investigation shows that deposition rate increases with the sputtering power increasing and the sputtering pressure and N2/Ar flow proporation decreasing, and insensitive to growth temperature.3. XPS and FTIR show that Al and N element form AlN compond. XRD analysis shows that the films grown in room temperature are of amorphous structures , but of polycrystalline structures when the growing temperature rises. The films' (100) plane grows preferencially under small sputtering power and high N2/Ar flow proporation. growth mechanismis discussed in details.4. Improving the growing temperature and sputtering power is beneficial to the adhesion of AlN film in high temperature treatment.5. We prepared AIN/Si and AIN/Ge film system on diamond successfully. AlN/Ge//Diamond film systems proved to be antireflected. The high temperature oxidation show that A1N film systems give a good protection to diamond, and have a good reliability in high temperature environment, because the IR transmittance have only a little decline.