Device for Treating an Object with Plasma

Abstract

A system for treating an object with plasma includes a vacuum processing chamber having a holder on which the object to be treated is placed, at least two subassemblies each including at least one plasma source able to generate a plasma and being supplied with radio-frequency power Pi and with a gas i of independent flow rate ni. The plasma generated by one of the subassemblies is a partially ionized gas or gas mixture of different chemical nature from the plasma generated by the other subassembly or subassemblies. A process for selectively treating a composite object employing such a device is described.

1 - 17 . (canceled) 
     
     
         18 . A system for the treatment of an object by plasma comprising:
 a treatment vacuum chamber having a support on which the object to be treated is placed; and   at least two subassemblies each comprising at least one plasma source allowing a plasma to be generated, each plasma source of a subassembly being supplied by radio frequency power Pi and independently by a gas i at a flow-rate ni, wherein plasma generated by one subassembly is a partially ionized gas or a gas mixture, of a different chemical nature from plasma generated by the other subassembly or subassemblies.   
     
     
         19 . The system according to  claim 18  wherein each source of plasma of a subassembly comprises:
 a gas inlet system; 
 a discharge chamber made of a plasma-inert material; 
 a device for coupling the radiofrequency (RF) power to the discharge chamber; and 
 a gas outlet. 
 
     
     
         20 . The system according to  claim 18  further comprising a control device to control each of the subassemblies depending upon a specific parameterization by application of radiofrequency power Pi and/or a flow-rate of gas ni specific to each subassembly. 
     
     
         21 . The system according to  claim 18  wherein each subassembly comprises a gas inlet specific to the subassembly connected to the gas inlet of each plasma source of the subassembly. 
     
     
         22 . The system according to  claim 18  wherein each subassembly comprises a conducting element connected to the coupling device of each plasma source of the subassembly. 
     
     
         23 . The system according to  claim 18  wherein the subassemblies are arranged along concentric rings. 
     
     
         24 . The system according to  claim 18  wherein the subassemblies are arranged in parallel. 
     
     
         25 . The system according to  claim 24  wherein each subassembly comprises at least two plasma sources, each plasma source comprising two chambers in series. 
     
     
         26 . A selective plasma treatment process of a composite object comprising at least two different materials A and B, the process implementing a treatment system according to  claim 18  and comprising the following steps:
 generating a first plasma by a first of the subassemblies and treating the object using the first plasma; 
 generating a second plasma by a second of the subassemblies and treating the object using the second plasma. 
 
     
     
         27 . The process according to  claim 26  wherein the plasma generation steps are repeated alternately, or with partial or total overlap. 
     
     
         28 . The process according to  claim 26  wherein the plasma generating steps are repeated with a partial overlap of the steps by at most 25%. 
     
     
         29 . A process for an etching treatment of a composite object that has at least two layers of different materials A and B with the layer of material A covering at least partially the layer of material B, the process comprising:
 treating, using a first plasma, at least a first zone of the object comprising on the surface, the material A, said treating using the first plasma comprising a passivation or activation of material B; and   treating, using a second plasma, at least a second zone of the object comprising on the surface, the material A, the treating using the second plasma comprising partial or total removal of material A, to form a zone comprising the material B on the surface when the removal is total, the process able to start either with a step of activation or passivation using the first plasma, or with a step of removal using the second plasma.   
     
     
         30 . The process according to  claim 29  wherein the first and second treating steps are performed in an alternating manner according to a periodicity varying between 0.5 seconds and 120 seconds until a desired removal of material A is obtained. 
     
     
         31 . The process according to  claim 29  wherein a ratio of a duration of the activation step or the passivation step to a duration of the removal varies between 0.1 and 10. 
     
     
         32 . The process according to  claim 29  wherein the first material A is silicon nitride Si 3 N 4  and the second material B is the oxide of silicon SiO 2 . 
     
     
         33 . An etched composite object obtained by the process according to  claim 29 . 
     
     
         34 . The composite object according to  claim 33  comprising one of an integrated circuit wafer, a substrate for a flat screen, a substrate for solar cells, or a substrate for an electronically printed device.