Method of making a registration mark on a semiconductor
AssigneeAnalog Devices, Inc.
InventorsHerbert J. Barber, Pamela A. Mayernik
Life of this patent
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Abstract
The process of making a registration mark on an integrated-circuit substrate wherein photoimaging first is used to define an optically-recognizable mark on a predetermined position of the substrate, and the substrate then is covered with silicon dioxide. Photoresist then is applied over the substrate and selectively removed except over the mark. Etchant then is applied to remove all silicon dioxide except over the photoresist-covered mark. An epitaxial layer thereafter is grown over the substrate. The silicon dioxide over the mark prevents epitaxial growth in that region, so that the mark remains clear and optically visible for the rest of the IC processing.
Claims12
For making a registration mark on a semiconductive substrate to be used for alignment purposes during integrated-circuit processing of the substrate, the method comprising the steps of:
- developing a distinctive characteristic defining a particular location on said substrate;
- placing over said substrate at said location an epitaxial-resistant material serving to present an optically-recognizable mark representing said distinctive characteristic so as to identify said location;
- and
- growing on said substrate an epitaxial layer the growth of which is prevented at said location by said epitaxial-resistant material.
For making a registration mark on a semiconductive substrate to be used for alignment purposes during the integrated-circuit processing of said substrate, the method comprising the steps of:
- developing a layer of insulative material on said substrate;
- forming said insulative material in one location to define a registration mark;
- applying over said insulative material a layer of epitaxial-resistant material facilitating optical observation of said mark;
- removing said insulative material and said epitaxial-resistant material from regions of said substrate other than in said one location;
- and
- growing on said substrate an epitaxial layer which is non-adherent to said epitaxial-resistant material at said location.
Dependencies are inferred from the claim text.