| 摘要 |
A process for etching polysilicon wherein CFCl3 (Freon 11) and another gas, typically SF6, is pre-mixed in a storage chamber (1) before routing to an etching chamber (5). This process prevents condensation of the Freon 11 in a routing line and resultant failure of a mass flow controller (3) due to liquid ingestion. Furthermore, since the gases are pre-mixed and only one mass flow controller is used, the accuracy of the mixture is not dependent on the precision of the mass flow controller. |
