Browse Prior Art Database

Apertured Evaporation Mask

IP.com Disclosure Number: IPCOM000095458D
Original Publication Date: 1964-Jan-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 25K

Publishing Venue

IBM

Related People

Croisier, A: AUTHOR

Abstract

In the fabrication of semiconductor devices, it is sometimes required to apply a conductivity-directing impurity to a selected portion of a substrate through a minute aperture in a silicon oxide mask. This mask is deposited on the substrate by evaporation and adheres firmly to it.

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Apertured Evaporation Mask

In the fabrication of semiconductor devices, it is sometimes required to apply a conductivity-directing impurity to a selected portion of a substrate through a minute aperture in a silicon oxide mask. This mask is deposited on the substrate by evaporation and adheres firmly to it.

A stencil 10 having a pair of apertures 11, 11 shaped like butterfly fly wings, as in A is placed on the surface of a semiconductor substrate, not shown. Then, silicon oxide is evaporated so that films 12, 12, shown by the shading, cover the surfaces of the substrate exposed by apertures 11, 11.

Next, stencil 10 is rotated 90 degrees on the substrate and more silicon oxide is evaporated. The pattern of the resulting oxide film 13 has the configuration shown in B and contains in the desired location a sharply defined aperture 14 having the required dimensions, An impurity can now be suitably positioned in the aperture for alloying with the semiconductor substrate or can be diffused into the substrate through the aperture.

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