Browse Prior Art Database

Disposable Electroless Copper Cathode

IP.com Disclosure Number: IPCOM000077654D
Original Publication Date: 1972-Sep-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Desai, KS: AUTHOR

Abstract

A thin-metal layer (800-1000 Angstroms) is selectively deposited on a chromium cathode used in connection with a metal interconnection pattern on dielectric substrate 10, typically ceramic or glass in order to enhance conductivity.

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Disposable Electroless Copper Cathode

A thin-metal layer (800-1000 Angstroms) is selectively deposited on a chromium cathode used in connection with a metal interconnection pattern on dielectric substrate 10, typically ceramic or glass in order to enhance conductivity.

Initially, metallurgical regions 12 and 14 are formed by selective formation over a chrome cathode layer 17, and each comprises respective copper layers 16, chromium layers 18, copper layers 20, and upper photoresist layers 22.

After copper etching used to form the structure illustrated in Fig. 1, substrate 10 is cleaned using a 1:1 neutral cleaner solution at 60 degrees C for 45 seconds. This step is followed by a water rinse and then the substrate 10 is dipped into a 0.01% pdCl(2) solution for 15 seconds and then again rinsed with water. A very thin layer of palladium is deposited on the plurality of copper traces 24, which remained after the previously described etching step.

The thin layers of palladium deposited on the plurality of copper traces 24 are sufficient to initiate an electroless copper plating operation for depositing a 800- 1000A copper layer 26, which can be suitably formed by immersing the substrate in an electroless copper bath for 4-5 minutes at 25 degrees C, Fig. 2. The substrates then can be rinsed and the photoresist layers 22 stripped away.

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