Effect of the hydrogen partial pressure ratio on the properties of mu c-Si: H films prepared by rf magnetron sputtering

We prepared hydrogenated microcrystalline silicon (muc-Si:H) films by an r. f. magnetron sputtering method at gas pressure of 8.0 Pa, power of 100 W an d substrate temperature of 240 degreesC, using argon and hydrogen mixture g as and investigated the effect of the hydrogen partial pressure ratio (R(H- 2)) on the him properties. The optical emission spectra of the r.f, glow di scharge were also measured during the film deposition. As R(H-2) increased the deposition rate and the optical emission intensity of Ar decreased. The mean crystallite size increased with an increase of R(H-2) to about 50% an d decreased with further increase of R(H-2). The crystalline volume fractio n estimated by the Raman spectra and the XRD peak intensity increased with increasing R(H-2) upto about 60% and decreased as R(H-2) increased in range above 60%. These results also showed the same dependence as that of the op tical emission intensity of H-2 on R(H-2). It was found that the muc-Si:H f ilms with high crystallinity should be prepared under the condition of high optical emission intensity of H-alpha. (C) 2000 Published by Elsevier Scie nce Ltd.