MICROWAVE PLASMA CVD IN THE SYSTEM SI-C-H-AR - EFFECT OF PROCESS PARAMETERS

Si-C films were prepared on steel by the microwave (2.45 GHz) decompos ition of tetramethylsilane (TMS) diluted in argon. The device used dec ouples the plasma power and the substrate temperature. The effects of various parameters (substrate position, temperature, gas flow rate, po wer, pressure) on composition and deposition rate were investigated. T hey are discussed in relation to electrostatic probe measurements. For all conditions, deposition rates are high (3-60 mu m h(-1)). By using only TMS, the Si/C ratio in the films is restricted to values between 0.3 and 0.7. The variations in the process parameters do not induce s ignificant changes in film compositions, however, they significantly c hange the deposition rates and the film hardness. In this field, the T MS dissociation process seems quite invariant with the conditions With the introduction of SiH4 to the input gas phase (i.e., mixture SiH4 TMS + Ar), silicon-rich films were obtained. The composition range wa s extended to Si/C = 1.7 but the mechanical properties are strongly ch anged.