摘要 |
In a plasma reaction chamber or the like having a supporting electrode for receiving a selected substrate to be etched, a coolant gas is introduced into one region between this substrate and electrode for increasing the heat transfer capacity therebetween. Differential sealing means are provided adjacent to the coolant gas receiving region and define an enclosed space between the substrate and its supporting electrode to which a partial vacuum may be applied. This partial vacuum prevents any cooling gas from by-passing the sealing means and entering the plasma reaction chamber and producing deleterious chemical reaction effects therein.
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