The computer program for prediction of plasma parameter, density, electron temperature, and etc., of ECR(electron cyclotron resonance) plasma which is used in etching and thin film deposition for semiconductor was developed, by which the parameters were predicted in various conditions.
The general transport equation was developed after physical consideration of interactions in the plasma and spatially averaged to yield the equation of the averaged quantities with which the equation of ambipolar potential derived from the relations of quasi-neutrality, Boltzmann distribution of electron density, conservation of density and magnetic field flux, and free fall model of the ion were used for deriving the equation of the half dimensional model. The numerical solutions of these two, averaged transport equation and equation of the ambipolar potential, were calculated at the steady state.
The implicit FDM(finite difference method), with time and the distance along axis as independents, was used as a numerical method for the calculation of the variation of the spatial averages for plasma density, electron temperature and ion temperature, and the distribution of the ambipolar potential and the plasma density along the axis.
The results of the calculations with various microwave power absorbed by the plasma, initial kinetic energy of the ion given by the potential drop in the ECR layer, and neutral gas pressure are as follows. The plasma density is about linearly proportional to the power absorbed by the plasma and the ionization efficiency is maximized at a particular neutral gas pressure. The electron temperature crucially depends on neutral gas pressure and the ambipolar potential which makes a dominant effect on ion energy is similar to electron temperature in the dependence. The plasma density decreases as the distance from the ECR layer increases along axis.
