CRYSTALLIZATION OF HYDROGENATED AMORPHOUS-SILICON DEPOSITED AT HIGH-RATE BY DC MAGNETRON SPUTTERING

The crystallization of hydrogenated amorphous silicon (a-Si:H) films i s studied by thermally annealing in the temperature range between 620 and 660 degrees C. The films are deposited by de magnetron sputtering on a quartz substrate at a rate around 1.5 nm/s. The crystallization k inetics are studied from the electrical conductivity which is measured in-situ under vacuum during thermal annealing. In the growth regime, the electrical conductivity variation can be fitted by a known crystal lization model. This model permits determination of the characteristic time (t(c)) of the kinetics. The variation of t(c) versus the tempera ture of annealing shows a linear dependence in the Arrhenius represent ation. The t(c) and its activation energy are related to the growth an d nucleation phenomena and t(c) is dependent on the film thickness. It s activation energy is 3.4 eV for a 0.64-mu m thick film and 2.4 eV fo r a 1.4-mu m thick film. (C) 1998 Elsevier Science B.V. All rights res erved.