시설장비 설명 |
graphite particle, whose parameter was 0.1 to 0.5㎜, is used. The ignition point was measured with changed the energy using Ar laser. The experimental results indicate that there is a minimum laser power required for ignition a particle size and mixture gas. The measured critical minimum laser power for ignition decreases as the particle size become to be small. Pyrolytic dissociation of silane on substrates heated by a cw Ar ion laser beam has been used to deposit polycrystalline silicon thin films. The effects of parameters like laser beam irradiance (power density), dwell time, silane pressure on the silicon deposition are studied. To understand the film growth kinetics, an approximate relationship amongst the film thickness and some of the above parameters is deduced from general chemical thermodynamic considerations. The crystallographic texture of the grown silicon film is studied as a function of laser power. It is found that the texture (preferred orientation) changes from 〈110〉 at low power to 〈111〉 at higher power. Mixtures of silane and phosphine at different partial pressures are used to obtain phosphorous doped polysilicon films. These films show a thermally activated conductivity σ = σ0 exp ( -Ea/kT) with the activation energyEa depending on the phosphine partial pressure. |