Preparation of electrically conductive diamond-like carbon films using i-C4H10/N-2 supermagnetron plasma

Electrically conductive diamond-like carbon (DLC) films were deposited by s upermagnetron plasma chemical vapor deposition. The deposition was made on Si and glass wafers using mixed isobutane (i-C4H10) and N-2 gases. The phys ical properties of deposited film were measured and analyzed. Fourier trans form infrared spectroscopy measurements revealed that the absorption due to N-H, C-N, and C=N bonds increased with increases in N-2 gas concentration. The increase in electrical conductivity could be attributed to C-N and C=N bond creation in the DLC films. The lowest resistivity, 0.17 Omega cm, was achieved at an N-2 concentration of 70%, gas pressure of 50 mTorr, lower e lectrode temperature of 160 degreesC, and rf powers of 1 kW/1 kW. The lowes t resistivity film was 1750 kg/mm(2) hard, harder than glass (1340 kg/mm(2) ). Raman spectroscopy measurements revealed two peak D and G bands, and the D band was more intense than the G band. The optical band gap decreased wi th increases in the N-2 concentration. Hall measurements showed that the ca rrier was n type and both carrier density and Hall mobility increased with rf powers. (C) 2001 American Institute of Physics.