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Method of Producing Thin-Film Patterns

IP.com Disclosure Number: IPCOM000046231D
Original Publication Date: 1983-Jun-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 45K

Publishing Venue

IBM

Related People

Hafner, B: AUTHOR [+3]

Abstract

An organic etch mask with a vertical profile, which serves to dry etch aluminum, is produced in a trilayer process. The etch mask is highly resistant to chlorine-containing plasmas.

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Method of Producing Thin-Film Patterns

An organic etch mask with a vertical profile, which serves to dry etch aluminum, is produced in a trilayer process. The etch mask is highly resistant to chlorine-containing plasmas.

Fig. 1A shows a substrate 1 which forms part of a chip. An aluminum layer 2 with a thickness of about 1 to 2 mm is vapor deposited onto this substrate. Subsequently, a layer 3 of polyimide or polytriethynyl benzene with a thickness of about 1 to 2 mm is spun on to layer 3 and cured at 400OEC for 1 hour. This is followed by a plasma deposited SiO2 layer 4 with a thickness of 0.1 mm. A photoresist layer 5 with a thickness of about 0.5 to 1.0 mm is spun onto layer 4, exposed and developed. Using photoresist mask 5 (Fig. lB), layers 4, 3, 2 are reactively ion etched under the following conditions:

SiO2 layer 4: with CF4 gas flow rate: 30 cm3/min. pressure: 40 mbar energy density: 0.2 W/cm2

polyimide layer 3: with O2 gas flow rate: l00 cm3/min. pressure: 2.5 to 3.0 mbar energy density: 0.3 W/cm2

aluminium layer 2: with C12/Ar gas flow rate: 20 cm3/min. pressure: 10 mbar energy density: 0.2 W/cu2

The organic layer 3 or 5 is stripped in an O2 plasma. By means of the method described, an Al conductor structure (Fig. 1C) with a vertical profile is obtained.

The method yields vertical mask profiles with little undercutting. The trilayer structure including the thick polyimide layer permits planarizing the surface topology of the wafer. The thin topmost pho...