PLASMA PROCESSING APPARATUS AND METHOD FOR THE PLASMA PROCESSING OF SUBSTRATES
A plasma processing apparatus ( 30, 50 ) comprises a process chamber with process chamber walls ( 35 ), process gas inlet means and process gas distribution means in said process chamber, exhaust means for removal of residual gases and a substrate mount ( 34 ) for a substrate ( 33 ). In a first embodiment a conductive plate ( 51 ) is arranged within said process chamber, electrically connectable with at least one RF power source ( 39 ) facing said conductive plate ( 51 ), exhibiting a pattern of openings and arranged at a distance to a backside wall ( 53 ) of said process chamber so that a process gas delivered to a gap ( 55 ) between the conductive plate ( 51 ) and said backside wall ( 53 ) does not ignite a plasma in the gap ( 55 ) during operation. In a second embodiment a first and second electrode are arranged within said process chamber adjacent each other with a gap in-between. The first electrode is connectable to a RF power source and the second electrode is connected to ground. The second electrode exhibits a pattern of openings and is arranged at a distance such that a process gas delivered to said gap does not ignite a plasma during operation.
1 . A plasma processing apparatus ( 30 ) comprising
a process chamber with process chamber walls ( 35 ), process gas inlet means and process gas distribution means, exhaust means for removal of residual gases, at least a first and second electrode ( 31 , 32 ) arranged adjacent to each other thus forming a gap ( 38 ) in-between, at least one RF power source ( 39 ) electrically connectable with said electrodes ( 31 , 32 ), and a substrate mount ( 34 ) for a substrate ( 33 ) facing second electrode ( 32 ), characterized in that the second electrode ( 32 ) exhibits a pattern of openings ( 36 ) and is arranged at such a distance to the first electrode ( 31 ) that a process gas delivered to the gap ( 38 ) between the electrodes ( 31 , 32 ) does not ignite a plasma in the gap ( 38 ) during operation and wherein the second electrode is grounded.
2 . An apparatus according to claim 1 , wherein the distance between first electrode ( 31 ) and second electrode ( 32 ) is essentially between 1 to 3 mm.
3 . An apparatus according to claim 1 or 2 , wherein the second electrode is designed as a plate with a thickness between 1-15 mm.
4 . An apparatus according to claims 1 or 2 , wherein the substrate mount ( 34 ) is connectable to a second RF power supply ( 40 ).
5 . A plasma processing apparatus ( 50 ) comprising a process chamber with process chamber walls ( 35 ), process gas inlet means and process gas distribution means in said process chamber, exhaust means for removal of residual gases, a conductive plate ( 51 ) arranged within said process chamber, electrically connectable with at least one RF power source ( 39 ) and a substrate mount ( 34 ) for a substrate ( 33 ) facing said conductive plate ( 51 ), characterized in that the conductive plate ( 51 ) exhibits a pattern of openings and is arranged at a distance to and facing a backside wall ( 53 ) of said process chamber so that a process gas delivered to a gap ( 55 ) between the conductive plate ( 51 ) and said backside wall ( 53 ) does not ignite a plasma in the gap ( 55 ) during operation.
6 . An apparatus according to claim 5 wherein the substrate mount ( 34 ) is connectable to a second RF power supply ( 40 ).