Browse Prior Art Database

External Rework Process for Multilevel Metal Integrated Circuits

IP.com Disclosure Number: IPCOM000051733D
Original Publication Date: 1981-Mar-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Fritzer, BM: AUTHOR [+2]

Abstract

In the fabrication of multilevel integrated circuit devices, defects in the metallurgy often occur and render a device inoperative. Many times the defect is major, and correction requires that the metallurgy be removed. In stripping off this metallurgy, the acids utilized for the removal of the metallurgy can also cause etching or removal of previous underlying metallurgy, such as device contacts, which should not be removed. The removal of metallurgy in these device contacts can render the device inoperative even when additional metallurgy is placed on its surface because of the loss of electrical continuity.

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External Rework Process for Multilevel Metal Integrated Circuits

In the fabrication of multilevel integrated circuit devices, defects in the metallurgy often occur and render a device inoperative. Many times the defect is major, and correction requires that the metallurgy be removed. In stripping off this metallurgy, the acids utilized for the removal of the metallurgy can also cause etching or removal of previous underlying metallurgy, such as device contacts, which should not be removed. The removal of metallurgy in these device contacts can render the device inoperative even when additional metallurgy is placed on its surface because of the loss of electrical continuity.

This article teaches a relatively simple way of protecting selected areas of the device while at the same time permitting gross areas of the defective metallurgy to be removed.

In Fig. 1, there is shown a body of silicon material 10 having a diffusion 11 therein. This diffusion is contacted by a first level of metal 12, while the remainder of the body 10 is coated with an oxide layer 13. A portion of the oxide layer is opened over the first metal layer 12, and a second level metal layer 14 is deposited through the oxide so that it contacts the first metal layer 12 and is supported above the body 10 by the oxide layer 13.

It will be assumed that this second metal layer 14 is defective, and correction requires the stripping of this layer. To prevent the stripping of the layer 14 from causing adv...