载气对化学气相沉积中气体流场、反应物与热解炭沉积率影响的仿真研究（英文）

Numerical simulation of carrier gas effects on flow field,species concentration and deposition rate in the chemical vapor deposition of carbon

为了研究载气对化学气相沉积过程的影响,采用二维仿真模型,模拟立式反应炉中化学气相沉积过程。并建立了全组分扩散模型描述化学气相沉积过程中气体分子间的扩散过程。研究了氢气,氮气和氩气对气体流场,反应物浓度场以及热解炭沉积率的影响。结果表明,氢气有利于提高气体流场的稳定性;氢气有利于反应物的扩散,以氢气作为载气时,沉积壁面CH_4,C_2H_2,C_2H_4和C_6H_6的浓度均匀性较好。采用氩气和氮气作为载气时,沉积率均高于氢气做载气的情况,但热解炭的沉积均匀性低于氢气做载气时的情况。仿真结果与实验吻合较好。

A 2D numerical model was established for simulating the chemical vapor deposition（ CVD） of carbon in a vertical reactor.A full multi-component diffusion model was proposed to describe the diffusion of the gas species. The effects of Ar,N2 or H2 carrier gases on the flow field,species concentration and deposition rate of pyrocarbon were investigated using C3H6 as the carbon source. Results show that H2 improves the stability of the gas flow. The concentration distributions of CH4,C2 H2,C2H4 and C6H6 are uniform in H2. The pyrocarbon deposition rate is lowered,but the uniformity of deposition is improved when H2 is used as the carrier gas compared with N2 or Ar. The simulation results agree well with the experimental ones.