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Plasma doping process and apparatus therefor

  • US 4,937,205 A
  • Filed: 08/04/1988
  • Issued: 06/26/1990
  • Est. Priority Date: 08/05/1987
  • Status: Expired due to Term
First Claim
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1. Method for plasma-doping of impurity on a semiconductor substrate comprising the steps of:

  • placing an object semiconductor substrate on a first electrode in a vacuum chamber,introducing a gas of a controlled reduced pressure containing at least one impurity, into said vacuum chamber,impressing a radio frequency current of a high voltage in intermittence across said first electrode and a second electrode in said chamber thereby causing radio frequency discharging in said chamber, to generate plasma doping, andcontrolling a duty ratio of said intermittence in accordance with a program to control the amount of impurity doped on a surface of said substrate.

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