Effect of Positive Bias and Pressure on Plasma Flow Characteristics in a Chemical Vapor Deposition Chamber

To better understand how positive bias and deposition pressure affect the plasma flow properties in the deposition chamber during the bias-enhanced MPCVD process, a two-dimensional axisymmetric model based on the discharge mechanism of pure H₂ was constructed. The coupling process between different physical field models of the electromagnetic field, plasma, and temperature field in the MPCVD reactor is realized. We studied the influence of positive bias voltage and deposition pressure variation on microwave plasma flow characteristics in the deposition chamber. There was a bias voltage threshold phenomenon in the case of positive bias, and the suitable value range was narrow. Additionally, with the increase in the deposition pressure, the electron temperature in the deposition chamber tends to increase locally and reaches its maximum value when the pressure is approximately 30 torr. It provides new ideas and guidance for optimizing the process parameter setting of the bias-enhanced MPCVD process.