Preparation of electrically conductive diamond-like carbon films using i-C4H10/N2 supermagnetron plasma

Abstract

Electrically conductive diamond-like carbon (DLC) films were deposited by supermagnetron plasma chemical vapor deposition. The deposition was made on Si and glass wafers using mixed isobutane (i-C4H10) and N2 gases. The physical properties of deposited film were measured and analyzed. Fourier transform infrared spectroscopy measurements revealed that the absorption due to N–H, C–N, and C≡N bonds increased with increases in N2 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 Ω cm, was achieved at an N2 concentration of 70%, gas pressure of 50 mTorr, lower electrode temperature of 160 °C, and rf powers of 1 kW/1 kW. The lowest resistivity film was 1750 kg/mm2 hard, harder than glass (1340 kg/mm2). 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 with increases in the N2 concentration. Hall measurements showed that the carrier was n type and both carrier density and Hall mobility increased with rf powers.

Sputter-assisted plasma CVD of wide or narrow optical bandgap amorphous CNx:H films using i-C4H10/N2 supermagnetron plasma

“…This absorption spectrum, with a strong absorption band at 1100-1700 cm − 1 and three weak absorption bands at 3350 cm − 1 , 2930 cm − 1 , and 2200 cm − 1 , is similar to the spectrum of DAC:N films reported in Ref. [18]. This experimental result means that a-CN x :H films deposited at higher LORF (region I) should correspond to the hard DAC:N films.…”

“…The thermal masses of Si and SiO 2 are similar; hence, the thermal (optical and vibrational) energy would accumulate more rapidly in the Si substrate and with consequent higher-temperature increase than in the glass substrate. With the increase of substrate temperature, the deposition rate of a-CN x :H films was increased [18]. By this way the higher deposition rate of the film on Si substrate in comparison with glass substrate can be explained.…”

Electrical and electronic properties of nitrogen doped amorphous carbon (a-CNx) thin films

“…During nitrogen doping, the NeH, CeN, and C^N bonds increased with increase in N 2 concentration. The increase in electrical conductivity could be attributed to CeN and C^N bond creation in the a-C films [17]. Fig.…”

Field-emission characteristics of diamond-like amorphous carbon films deposited by mixed gas (N2 or H2) controlled i-C4H10 supermagnetron plasma

“…The E TH of the p-Si substrate was 19 V/μm and that of the n-Si substrate was 26 V/ μm. Our DAC:N film have ever been reported to be n-type in electrical conductivity [25]. Therefore the DAC:N and p-Si interface should form pn junction.…”