Particle-in-Cell/Monte Carlo simulation of CF4 discharge in capacitively coupled plasma reactor
We present the structures of the CF4 radio-frequency discharge between parallel electrodes using the Particle-in-Cell/ Monte Carlo method. The simulation takes into account four types of charged species, CF3 , CF − 3 , F − ions, and electrons. The cross-sections of electron-CF4 collision processes are based on the paper of Kurihara et al. [1]. Positive–negative ion recombination which plays an important role in the charged particle balance is also considered in the model using method proposed by Nanbu and Denpoh [2]. The structure of the CF4 discharge is typically electronegative discharge and is characterized by the presence of negative ions (F− and CF3 ), which are the dominant negative charged species (see Fig. 1(a)). The electron density profile and electric field at phase in a rf period are shown in Fig. 1. The local maxima of the electron density is significant feature of electronegative discharges, which cannot be observed in electropositive discharges. Moreover, we can observe the double-layer structure (i.e. the local maxima or minima of the electric field) and the field reversal near the bulk-sheath interface. Historically, the double layer phenomena were first described experimentally and theoretically in rf glow SiH4 discharge by T. Makabe et al. [3]. In conclusion, the abundance of negative ions is one of the main features in the discharges and this profoundly influences the sheath dynamics such as electric field reversal, double layer structure and local maxima of electron density.
Monte Carlo Collision Simulation of Positive-Negative Ion Recombination for a Given Rate Constant
Here is proposed the Monte Carlo collision simulation method for the positive-negative ion recombination whose rate constant is given as a function of temperature. The method makes it possible to simulate a nonequilibrium state of ions in electric discharges.
Metallurgical Process Engineering
The "material of choice" - steel.- Uprising of China's steel industry.- Process manufacturing industry and process engineering.- Engineering science in steel manufacturing process.- Analysis and integration of metallurgical manufacturing process.- Multi-dimensional mass flow control for metallurgical manufacturing process.- Time factors in steel manufacturing process.-Operating dynamics in the production process of steel plant.- Structure and mode of steel plant.- Steel plant and environment.