Vacuum Processing Chamber for Very Large Area Substrates
A plasma reactor for PECVD treatment of large-size substrates according to the invention comprises a vacuum process chamber as an outer chamber and at least one inner reactor with an electrode showerhead acting as RF antenna, said inner reactor again comprising a reactor bottom and a reactor top, being sealingly connected at least during treatment of substrates in the plasma reactor and separated at least during loading/unloading of the substrates. Further embodiments comprise a sealing for said reactor to/bottom and a suspender for the RF antenna/electrode showerhead.
1 . A plasma reactor for plasma enhanced chemical vapor deposition (PECVD) for treatment of large-size substrates, comprising a vacuum process chamber ( 19 ) as an outer chamber and at least one inner reactor with a process gas feed ( 22 ); and a RF feed ( 24 ) electrically connected to an electrode showerhead ( 25 ) acting as RF antenna, said inner reactor again comprising a reactor bottom ( 6 ) and a reactor top ( 2 ), being sealingly connected at least during treatment of substrates in the plasma reactor and separated at least during loading/unloading of the substrates.
2 . The plasma reactor according to claim 1 , wherein the vacuum process chamber ( 19 ) shows an opening with a chamber gate valve ( 20 ) allowing the loading and unloading of substrates into the vacuum process chamber ( 19 ).
3 . The plasma reactor according to claim 1 , wherein pins ( 8 ) in the reactor bottom support the substrate ( 7 ) to be treated.
4 . The plasma reactor according to claim 1 , wherein the reactor bottom ( 6 ) is vertically movable to separate and seal reactor top ( 2 ) and reactor bottom ( 6 )
5 . The plasma reactor according to claim 1 , wherein a sealing plate ( 9 , 9 a ) interacts with a side wall ( 11 ) of reactor top ( 2 ) to be sealingly pressed against reactor bottom ( 6 ).
6 . The plasma reactor according to claim 5 , wherein in the closed state of said inner reactor the sealing plate ( 9 a ) is conceived to be pressed by means of springs ( 10 ) to an inner side of the reactor bottom ( 6 ) and to the reactor side wall ( 11 ).
7 . The plasma reactor according to claim 5 , wherein a sealing spacer ( 9 b ) is arranged under the center of the sealing plate ( 9 a ).
8 . The plasma reactor according to claim 1 , wherein stiffeners ( 1 ) support reactor top ( 2 ) and/or reactor bottom ( 6 ).
9 . The plasma reactor according to claim 8 , wherein the stiffeners ( 1 ) are connected to reactor top ( 2 ) and/or reactor bottom ( 6 ) via compensation spacers ( 4 ) with thicknesses chosen to compensate the thermal expansion during operation.
10 . The plasma reactor according to claim 9 , wherein the compensation spacers ( 4 ) arranged between the stiffener ( 1 ) and the reactor top ( 2 ) are thicker at the end and thinner towards the middle of the stiffener ( 1 ).
11 . The plasma reactor according to claim 9 , wherein the compensation spacers ( 4 ) arranged between the stiffener ( 1 ) and the reactor bottom ( 6 ) are thickest in the center of the stiffener ( 1 ).
12 . The plasma reactor according to claims 9 , wherein screws ( 5 ) join stiffener ( 1 ) and reactor top ( 2 ) or reactor bottom ( 6 ) respectively, with the aid of stiffener clips ( 3 ) and compensation spacer ( 4 ).
13 . The plasma reactor according to claim 1 , wherein a suspender ( 21 ) connects RF antenna ( 12 ) and reactor top ( 2 ), said suspender comprising a top part ( 14 ), a middle part ( 16 ) and a bottom part ( 17 ), said top part ( 14 ) being on the same potential as the reactor top ( 2 ), said bottom part ( 17 ) being on the same potential as the RF antenna ( 12 ) and the middle part ( 16 ) and said middle part connecting and electrically isolating said top part ( 14 ) and bottom part ( 17 ).
14 . The plasma reactor according to claim 13 , further comprising RF spacers ( 18 ) in the space between reactor top ( 2 ) and RF antenna ( 12 ).
A method for treating a substrate in a plasma reactor according to claim 1 comprising the steps of (a) opening the inner reactor by vertically lowering the reactor bottom ( 6 ), (b) opening a chamber valve gate ( 20 ) giving access to the inner reactor,(c) accommodating the substrate ( 7 ) on pins ( 6 ), (d) lifting vertically the reactor bottom ( 6 ) until the inner reactor is closed, (e) closing the chamber valve gate and (f) treating the substrate.