Influence of different precursor gases on DLC film
In the process of DLC film preparation, hydrocarbon precursor gases are used, and different precursors have different effects on the performance of the film.The effects of a series of hydrocarbon precursors on film hardness, bonding strength and deposition rate were evaluated. The film hardness is increased from 15GPa of acetylene to 25GPa of butene, and the deposition rate is kept high.Eight different gaseous hydrocarbon precursors were used to evaluate and characterize the high hardness, deposition rate and binding ability of the films. Hydrocarbons were chosen to contain single -, double -, and triple-bonded carbons and different ratios of hydrogen/carbon in the precursor molecules. All precursors were evaluated using the same process conditions. It can be seen from Figure 1, 2 and Table 1 that butene has the best binding strength, hardness and deposition rate. Sp3 content was determined by Raman spectroscopy, and hydrogen content was determined by hydrogen forward scattering (HFS).Then the process conditions were optimized, and the hardness was further significantly increased by nearly 50%, with only a slight decrease in the deposition rate. A trend was observed in the hardness data based on the saturation of the molecule. Fully saturated molecules (methane and hexane) have higher hardness, while less saturated molecules have lower hardness, such as triple-bonded acetylene has the lowest hardness, and multi-double-bonded benzene also has lower hardness.DLC film