Plasma etching apparatus and plasma etching method

Abstract

A plasma etching apparatus performs plasma etching on a substrate having a resist pattern formed thereon and an outer edge portion where the substrate surface is exposed. The plasma etching apparatus includes a support part that supports the substrate, a cover member that covers the outer edge portion of the substrate and prevents plasma from coming around the outer edge portion, and a control unit that generates plasma by controlling high frequency power application and supply of a processing gas for etching, and uses the generated plasma to etch the substrate that is supported by the support part and has the outer edge portion covered by the cover member. After etching the substrate, the control unit generates plasma by controlling high frequency power application and supply of a processing gas for ashing, and uses the generated plasma to perform ashing on the resist pattern on the etched substrate.

1 . A plasma etching apparatus that performs plasma etching on a substrate having a surface portion on which a resist pattern is formed and an outer edge portion where a substrate surface of the substrate is exposed, the plasma etching apparatus comprising:
 a support part that supports the substrate;   a cover member that covers the outer edge portion of the substrate that is supported by the support part, the cover member being configured to prevent plasma from coming around the outer edge portion of the substrate; and   a control unit that generates plasma by controlling application of a first high frequency power from a first high frequency power supply and supply of a processing gas for etching from a first processing gas supply source, and uses the generated plasma to etch the substrate that is supported by the support part and has the outer edge portion covered by the cover member, wherein after etching the substrate, the control unit generates plasma by controlling application of a second high frequency power from a second high frequency power supply and supply of a processing gas for ashing from a second processing gas supply source, and uses the generated plasma to perform ashing on the resist pattern on the etched substrate.   
     
     
         2 . The plasma etching apparatus as claimed in  claim 1 , wherein
 the substrate subject to the plasma etching is a bonded substrate, which includes a first substrate and a second substrate that are bonded together via an adhesive, the bonded substrate having the surface portion on which the resist pattern is formed and the outer edge portion where the adhesive is exposed.   
     
     
         3 . The plasma etching apparatus as claimed in  claim 1 , wherein
 the substrate has a circular plate form and the substrate surface of the substrate is exposed at a region extending over a first predetermined width from an outer edge of the substrate; and   the cover member has a ring-shaped form, and an inner diameter of the cover member is determined based on an outer diameter of the substrate and the first predetermined width.   
     
     
         4 . The plasma etching apparatus as claimed in  claims 3 , wherein
 the inner diameter of the cover member is determined based on the outer diameter of the substrate, the first predetermined width, and a second predetermined width that depends on a positioning accuracy of a relative position of the substrate with respect to the cover member.   
     
     
         5 . A plasma etching method for performing plasma etching on a substrate having a surface portion on which a resist pattern is formed and an outer edge portion where a substrate surface of the substrate is exposed, the plasma etching method comprising the steps of:
 supporting the substrate by a support part;   arranging a cover member to cover the outer edge portion of the substrate that is supported by the support part, the cover member being configured to prevent plasma from coming around the outer edge portion of the substrate;   generating plasma by controlling application of a first high frequency power from a first high frequency power supply and controlling supply of a processing gas for etching from a first processing gas supply source, and using the generated plasma to etch the substrate that is supported by the support part and has the outer edge portion covered by the cover member; and   after etching the substrate, generating plasma by controlling application of a second high frequency power from a second high frequency power supply and controlling supply of a processing gas for ashing from a second processing gas supply source, and using the generated plasma to perform ashing on the resist pattern on the etched substrate.   
     
     
         6 . The plasma etching method as claimed in  claim 5 , wherein
 the substrate subject to the plasma etching is a bonded substrate, which includes a first substrate and a second substrate that are bonded together via an adhesive, the bonded substrate having the surface portion on which the resist pattern is formed and the outer edge portion where the adhesive is exposed.   
     
     
         7 . The plasma etching method as claimed in  claim 5 , wherein
 the substrate has a circular plate form, and the substrate surface of the substrate is exposed at a region extending over a first predetermined width from an outer edge of the substrate; and   the cover member has a ring-shaped form, and an inner diameter of the cover member is determined based on an outer diameter of the substrate and the first predetermined width.   
     
     
         8 . The plasma etching method as claimed in  claims 7 , wherein
 the inner diameter of the cover member is determined based on the outer diameter of the substrate, the first predetermined width, and a second predetermined width that depends on a positioning accuracy of a relative position of the substrate with respect to the cover member.