| CPC H01L 21/31116 (2013.01) [H01J 37/32642 (2013.01); H01J 2237/334 (2013.01)] | 20 Claims | 

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               1. A dry etching apparatus comprising: 
            a plasma process chamber; 
                an edge ring which is arranged in the plasma process chamber and on which a wafer is mounted; 
                a shadow ring positioned to be spaced apart by a first vertical distance on the edge ring during a plasma etching process of the wafer; 
                an operation unit coupled to the shadow ring and having a lift pin that raises and lowers the shadow ring; 
                a fixing portion having a plurality of fixing pins, each of the plurality of fixing pins configured to move between an operating position in which the fixing pin is engaged with the lift pin at a respectively different position to fix a lowering point of the shadow ring and a standby position in which the fixing pin is spaced apart from the lift pin; and 
                a distance control unit configured to control the fixing portion to determine the first vertical distance and to adjust the first vertical distance by selecting any of the plurality of fixing pins, 
                wherein the first vertical distance is determined by a first horizontal distance between the wafer and the edge ring. 
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