Low temperature and large area deposition of nanocrystalline diamond films with distributed antenna array microwave-plasma reactor

作者：Mehedi H A^*; Achard J; Rats D; Brinza O; Tallaire A; Mille V; Silva F; Provent Ch; Gicquel A

来源：Diamond and Related Materials, 2014, 47: 58-65.

DOI：10.1016/j.diamond.2014.05.004

• Nanocrystalline diamond films
• Surface wave plasma
• Distributed antenna array CVD reactor
• Low-temperature low-pressure CVD of diamond
• Nanotribology

Diamond films grown at low temperature (%26lt;400 degrees C) on large area of different substrates can open new applications based on the thermal, electrical and mechanical properties of diamond. In this paper, we present a new distributed antenna array PECVD system, with 16 microwave plasma sources arranged in a 2D matrix, which enables the growth of 4-inch nanocrystalline diamond films (NCD) at substrate temperature in the range of 300-500 degrees C. The effect of substrate temperature, gas pressure and CH4 concentration in the total gas mixture of H-2/CH4/CO2 on the morphology and growth rate of the NCD films is reported. The total gas pressure is found to be a critical deposition parameter for which growth rates and crystalline quality both increasing with decreasing the pressure. Under optimized conditions, the process enables deposition of uniform (similar to 10%) and high purity NCD films with very low surface roughness (5-10 nm), grain size of 10 to 20 nm at growth rates close to 40 nm/h. Nanotribology tests result in the friction coefficient of the NCD films close to that obtained for the standard tetrahedral amorphous carbon coatings (ta-C) indicating the suitability of this low-temperature diamond coating for mechanical applications such as bearing or micro-tools.

• 出版日期2014-8