DEPENDENCE OF THE PHYSICAL-PROPERTIES OF SINX-H FILMS DEPOSITED BY THE ECR PLASMA METHOD ON THE DISCHARGE SIZE

SiNx:H films have been deposited using two different ECR plasma source s attached to a similar deposition chamber, a Compact source and an AX 4500 source both from Astex. The sources mainly differ in the discharg e volume, 55 cm(3) and 936 cm(3), respectively. Microwave power and N- 2/SiH4 gases now ratio have been varied to deposit the films. Depositi on rate, infrared absorption spectra, refractive index (n), and optica l band gap (E-g) of the films have been measured. Optical diagnosis sp ectra of the discharges have been recorded during the depositions. Dif ferent performances of the sources reflected in the film characteristi cs have been found. The properties of the films deposited using the Co mpact source correspond to films with compositions that range from Si- rich to near stoichiometric ones, while when using the AX4500 reactor, the film properties correspond to compositions close to the stoichiom etric films or to N-rich ones. When changing from the Compact source t o tile AX4500 reactor, the signal corresponding to N-2(+) ions and to the excited species, N-2(+) are higher in the AX 4500 than in the Comp act one, the deposition rate being higher in tile AX 4500 source. The different performances of the sources have been attributed to the diff erent discharge size and diffusion length, being optimal in the case o f the AX4500 source. (C) 1998 Elsevier Science S.A.