Browse Prior Art Database

Visual Inspection of Quartz Etch by Removable Stain

IP.com Disclosure Number: IPCOM000046026D
Original Publication Date: 1983-May-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Marcello, H: AUTHOR

Abstract

A removable nondestructive stain is used for visual inspection of the completeness or lack thereof of etched openings in a quartz layer.

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Visual Inspection of Quartz Etch by Removable Stain

A removable nondestructive stain is used for visual inspection of the completeness or lack thereof of etched openings in a quartz layer.

In etching openings in the insulative quartz layer covering an underlying circuitized metal layer of a silicon integrated circuit (IC) chip being fabricated, it is difficult to ascertain visually whether the quartz in the opening has been completely removed especially if the thickness of the remaining quartz in the openings is one hundred angstroms or less. To aid in the visual inspection, a stain which reacts with the underlying metal is applied through the tops of the via openings. If the etch is complete, the stain discolors with a distinctive color, e.g., brown, the underlying metal that is exposed in the openings thereby indicating that the etching is complete. On the other hand, if the metal is still covered by some quartz, no discoloration occurs, indicating that the etch is incomplete and that additional etching is required. The inspection is repeated by reapplying the stain after each subsequent etch as often as is necessary. The stain is easily removed with deionized (DI) water and does not effect the subsequent processing of the chip associated with the formation of an overlying circuitized metal layer on the upper surface of the quartz layer and metallization of the via openings for conductively interconnecting the underlying and overlying metal layers.

A typical st...