| 摘要 |
<p>A plasma etch apparatus (10) includes a vacuum chamber (15) surrounded by a cylindrical dielectric wall (13). A coil (20) surrounds the wall and is energized with medium frequency RF energy inductively coupled into the chamber to energize a plasma to etch a semiconductor wafer (16) on a support (17). A generally cylindrical Faraday shield (30) contacts the outside of the wall between the wall and the coil and has a plurality of axially oriented slits (32) closely spaced around the shield and extending less than the height of the shield. One slit (31) extends the full height of the shield and interrupts an otherwise continuous conductive path around the circumference of the chamber with a gap about 1/8 inch wide, so that, upon initial energization of the coil, a momentary peak-to-peak RF voltage across the gap generates an electric field in the chamber which ignites the plasma.</p> |
