Isobutane/N 2 Pulsed Radio Frequency Magnetron Plasma Chemical Vapor Deposition of Hydrogenated Amorphous Carbon Nitride Films for Field Emission Applications

Radio frequency (rf) supermagnetron plasma was modulated by pulse and was applied to the deposition of hydrogenated amorphous carbon nitride (a-CN x :H) films. The range of upper/lower electrode rf powers (UPRF/LORF) was selected as 200/50–800 W, and films were deposited using isobutane (i-C 4 H 10 )/N 2 plasma. Phase-controlled rf power (13.56 MHz) was modulated by a 2.5-kHz pulse frequency, and the duty ratio was selected as 12.5%. With increases in LORF, the optical band gap decreased from 1.3 to 0.6 eV, and the hardness became sufficiently high, reaching a peak (34 GPa) at LORFs of 200 and 400 W. A low field emission threshold of 11 V/µm was obtained in the films deposited at LORF of 400 W, and gas pressure of 4 Pa.