Zone heating required for good uniformity. Radid temperature changes may be implemented thought control is complex. Radial film uniformity Adjustable by changes in temperature and showerhead design. Productivity advantages Batch configuration with manual load. Easy in situ clean with plasma.
Every wafer sees an identical environment.
Process advantages Rapid change in gas conditions for multiple-layer films possible. Process disadvantages Plasma discharges tend to sputter contamination from reactor walls onto wafers, enhanced at electrode edges. Small showerhead dispense holes can clog or erode, degrading uniformity.