Hydrogenated amorphous carbon nitride films on Si(100) deposited by direct current saddle-field plasma-enhanced chemical vapor deposition

• Published in: Journal of vacuum science & technology. A, Vacuum, surfaces, and films Vacuum, surfaces, and films, 1999-09, Vol.17 (5), p.2607-2611
• Main Authors: Jang, H. K., Kim, G., Lee, Y. S., Whangbo, S. W., Whang, C. N., Yoo, Y-Z., Kim, H. G.
• Format: Article
• Language: English
• ISSN: 0734-2101; 1520-8559
• DOI: 10.1116/1.581919

Hydrogenated amorphous carbon nitride [a-C:H(N)] films were deposited on p-type Si(100) at room temperature with a substrate bias voltage of 200 V by direct current saddle-field plasma-enhanced chemical vapor deposition using methane and nitrogen as source gases. The structural and compositional changes of the a-C:H(N) films induced by the differential ratio of N 2 to CH 4 (n N 2 /n CH 4 ) were investigated using Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy. Initially, as nitrogen is added to the pure methane, the deposition rate decreases quite rapidly then less so as n N 2 /n CH 4 rises above 0.5. The deposition rate continues to gradually decrease with the increase of the n N 2 /n CH 4 . The ratio of N to C of the films saturated at 0.25 at the maximum of n N 2 /n CH 4 . The number of N–H and C≡H bonds in the films increased with n N 2 /n CH 4 but the number of C–H bonds decreased. The optical band gap energy of the films, as determined by the Tauc relation was lowered from 2.53 to 2.3 eV as the n N 2 /n CH 4 of the source gas changed from 0 to 4.