Browse Prior Art Database

Wafer Holder for Ion Implantation

IP.com Disclosure Number: IPCOM000044212D
Original Publication Date: 1984-Nov-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Hagmann, D: AUTHOR

Abstract

Wafer holders provided in ion implanters shield certain peripheral wafer areas against being implanted and thus becoming unsuitable as real estate for chip positioning. Such masking of wafer area by the wafer holder can be used to advantage for blanket ion implantation without a photoresist masking step (blanket implantation is employed for a blanket bipolar subcollector with trench isolation or for FET gates to adjust threshold voltages). Generally, the areas at the wafer periphery are not occupied by integrated circuit chips and thus may be used for test circuits which must be protected against implantation. A wafer holder, shaped as a peripheral masking frame, shields these test circuits against impinging ions during blanket ion implantation.

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Wafer Holder for Ion Implantation

Wafer holders provided in ion implanters shield certain peripheral wafer areas against being implanted and thus becoming unsuitable as real estate for chip positioning. Such masking of wafer area by the wafer holder can be used to advantage for blanket ion implantation without a photoresist masking step (blanket implantation is employed for a blanket bipolar subcollector with trench isolation or for FET gates to adjust threshold voltages). Generally, the areas at the wafer periphery are not occupied by integrated circuit chips and thus may be used for test circuits which must be protected against implantation. A wafer holder, shaped as a peripheral masking frame, shields these test circuits against impinging ions during blanket ion implantation. As the test circuits are relatively small, compared with the areas available for them, masking frame and wafer can be easily aligned, if required.

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