ANALYSIS OF A PULSED-PLASMA CHEMICAL VAPOR-DEPOSITION REACTOR WITH RECYCLE

A simplified model for a time-dependent plasma-assisted chemical vapor deposition reactor was developed based on transport and reaction principles. The model equations were solved by the method of lines using collocation on finite elements for the spatial discretization. Emphasis was placed on the deposition rate and uniformity as a function of reactor operating conditions. A pulsed-plasma reactor was analyzed, and compared to a continuous-wave (CW) plasma reactor. Under conditions which would result in high depletion of the precursor gas in the CW reactor, the pulsed-plasma reactor yielded improved uniformity, albeit the deposition rate was reduced. The effect of a recycle stream on both the CW and pulsed-plasma reactors was also studied. For the CW reactor, recycle was most beneficial under conditions of low depletion of the precursor gas. For cases of intermediate depletion of the precursor gas, a CW reactor with recycle or a combination of pulsed-plasma and recycle can result in nearly uniform deposit without sacrificing the deposition rate. Analytic solutions were derived for the CW reactor with recycle, and for a well-mixed pulsed-plasma reactor. The results apply equally well to pulsed-plasma etching reactors conforming to the model assumptions and operating under corresponding conditions. © 1990, The Electrochemical Society, Inc. All rights reserved.