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Cermet Resistor Process

IP.com Disclosure Number: IPCOM000049137D
Original Publication Date: 1982-May-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 2 page(s) / 64K

Publishing Venue

IBM

Related People

Abolafia, OR: AUTHOR

Abstract

A lift-off photoresist mask 5 is used to simplify the making of sputter cermet resistors.

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Cermet Resistor Process

A lift-off photoresist mask 5 is used to simplify the making of sputter cermet resistors.

Ceramic substrate 1 (Fig. 1) has a metallization multilevel pattern 2 of Cr-Cu- Cr (2A-2B-2C). Pattern 2 is personalized to include inter alia multiple pairs of spaced electrodes 3 and 4 for the intended resistors.

The photoresist mask 5, e.g., KTFR*, is applied over pattern 2 and the exposed ceramic substrate 1. Using known photolithographic techniques, an opening 6 is provided in mask 5 between electrodes 3 and 4 of each electrode pair. The spacing S of each opening 6 is selected to expose a small amount of the electrodes 3 and 4.

Prior to sputtering, the exposed top Cr (2C) and the Cu (2B) of electrodes 3 and 4 are etched through opening 6, resulting in their cut back below the edge of mask opening 6 and partial exposure of the bottom Cr (2A) (Fig. 2). After an oxide cleaning, a layer 7 of cermet is sputtered over mask 5 and through opening 6 to a thickness t slightly greater than the thickness of Cr (2A) to establish a more reliable contact between the cermet and the Cu (2B) (Fig. 3). During the sputtering operation, the temperature is controlled to prevent thermal decomposition of the mask 5.

Upon the completion of the sputtering operation, mask 5 is removed using a known stripping technique, resulting in the sputtered resistor structure shown in Fig. 4. * Trademark of Eastman Kodak Co.

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