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A bias power is usually applied in inductively coupled plasmas (ICP) to realize the separate control of the plasma density and the ion energy. In this research, a two-dimensional fluid/electron Monte Carlo hybrid model is developed to self-consistently investigate the bias effect on the stochastic heating and on the radial homogeneity in a biased argon ICP operated at low pressure (3 mTorr). The results show that the temporal evolution of the stochastic heating exhibits a plateau and a peak when the sheath collapses at high bias voltages, due to the limited sheath heating and the electron inertia. In addition, the plasma density in the diffusion chamber increases with bias voltage and bias frequency, because of the more pronounced stochastic heating both at the substrate and at the grounded wall. In the main discharge chamber, the plasma density decreases with bias voltage, due to the compression of the bulk plasma region, and this trend becomes less obvious at high bias frequency, because of the enhanced power absorption caused by the stochastic heating. Therefore, it is concluded that by tuning the bias voltage and bias frequency, the plasma radial uniformity could be modulated efficiently, which is very important for improving plasma processing.

In the etching process, a bias source is usually applied to the bottom electrode of an inductively coupled plasma (ICP) source to control the ion energy and angular distribution function (IEADF) independently. In this work, a hybrid model, i.e., a global model combined bi-directionally with a fluid sheath model, is applied to investigate the plasma properties in biased ICPs sustained in Cl2 gases. The evolutions of the plasma properties with bias voltage are presented for various ICP powers (i.e., 200, 500, and 1000 W) at a pressure of 10 mTorr and bias frequency of 13.56 MHz. The results indicate that the Cl2 (v = 0) density decreases with ICP power, whereas the densities of electrons and Cl+ ions increase strikingly and they become the dominant charged species at 1000 W. In addition, the electron density and Cl+ density increase with bias voltage, and the increasing trend becomes more obvious at higher ICP powers. However, the evolution of the Cl2+ density and Cl− density with bias voltage depends on the ICP power. For instance, they first exhibit an increasing trend and then keep constant at 200 W, while a slight downward trend is observed at 1000 W. In addition, as the bias voltage increases, both the high-energy peak and low-energy peak of IEADFs move toward higher energy, and meanwhile the peak separation becomes wider. The results obtained in this work are of significant importance for improving the etching process.