Temperature Distribution and Deposition Rate on Semiconductor Wafers in Low-Pressure CVD Equipment Processing Two Wafers

We studied hot-wall-type low-pressure chemical vapor deposition (LPCVD) equipment processing two wafers. The temperature distribution of the wafers and deposition rate of Si3N4 film in the LPCVD equipment were experimentally measured by changing parameters at 50 ° C.Results showed that the steady-state temperature deviation of the two wafers was within ±1.0 ° C. Change of wafer temperature during a continual heating process was 0.7 ° C by using the feed-forward control (FFC) method, which is less than half of that without the FFC method. The change of the deposition rate of the wafers during a continual deposition process was within 2% by using the FFC control method. The deviation of the deposition rate was reduced to ±1.3% by using the flip-flop flow of the process gas, which is 14% of that without the flip-flop flow.