Supermagnetron plasma chemical vapor deposition and qualitative analysis of electrically conductive diamond-like amorphous carbon films

Abstract

Using the i-C4H10/N2 supermagnetron plasma chemical vapor deposition method, electrically conductive diamond-like amorphous carbon (DAC) films with nitrogen (DAC:N) were formed on Si and SiO2 wafers. Resistivity and hardness were measured as a function of N2 concentration, rf power, total gas pressure, and wafer stage temperature. With an increase in the N2 concentration (up to 70%), rf power, and wafer stage temperature, DAC:N film resistivity decreased. Fourier transform infrared spectroscopy measurements revealed that an increase in electrical conductivity was attributed to the creation of C–N, C≡N, and N–H bonds in DAC:N films. By preheating the wafers using H2-plasma cleaning, the resistivity of the DAC:N film decreased with an increase in H2-plasma rf power. Using a preheated wafer, the lowest resistivity of 0.034 Ω cm was obtained at an N2 concentration of 65% and upper- and lower-electrode rf powers of 1 kW/1 kW.