Etching apparatus and method

Apparatus for etching the front surfaces of plural workpieces, said apparatus comprising

• a reaction chamber,
• two spaced-apart electrodes in said chamber, one of said electrodes having a planar base portion with post regions thereon,
• a dielectric plate member in contact with said base portion and encompassing said post regions, said plate member including a planar front surface having at least workpiece-sized portions removed therefrom in respective alignment with said post regions for mounting said workpieces such that the front surfaces of said workpieces lie in the same plane as the front surface of said plate member.

A method of making a device by processing a workpiece in accordance with a fabrication sequence that includes at least one dry etching step in which the workpiece is positioned on one of two spaced-apart electrodes in the reaction chamber of an etching system, said one electrode having a planar base portion with a post region thereon, said method comprising

• mounting said workpiece on said one electrode overlying said post region and in registry therewith to maintain the front surface of said workpiece in substantially the same plane as that of surrounding dielectric material disposed on said one electrode, the thickness of said surrounding dielectric material being substantially greater than the thickness of any dielectric material interposed between the back surface of said workpiece and said post region,
• introducing a gas into said chamber, and
• establishing an electric potential between said electrodes to form in said chamber a substantially uniform electric field focussed on said workpiece thereby to convert said gas into a plasma that contains species effective to react with selected portions of said front surface in a substantially uniform and contamination-free manner to etch said portions in a relatively rapid way.