Multiply steady states and nonequilibrium phase transition in chemical vapor deposition process
热解碳化学气相沉积中的多重定态和非平衡相变的研究

This paper is mainly concerned with the mechanism to produce multi-states and nonequilibrum phase transition in chemical vapor deposition (CVD) process. It was discovered that the polymerization reaction in CVD process is a typical nonequilibrum chemical reaction with a bifurcation structure and its steady state model of free radical is fit to the Schlogl model through carefully analyzing the mechanism and experimental results. There are linear and nonlinear areas in the nonequilibrum reaction system, and there is a nonequilibrum phase transition between the two areas. The CVD product in the linear area is different from that in the nonlinear area. The product in the linear area is pyrocarbon and that in the nonlinear area is the carbon black. Further study reveals that the function of deposition rate is linear and has only one formula when the CVD reaction system is in the linear area. But the function of deposition rate will be nonlinear, has multi-solutions and generates a bifurcation structure when the system goes into the nonlinear area. With the reaction condition being far from the equilibrium, the CVD reaction system will select the steady state branch that is far from equilibrium.