Browse Prior Art Database

Lift Off Process for Producing a Dense Metallization Pattern

IP.com Disclosure Number: IPCOM000045104D
Original Publication Date: 1983-Jan-01
Included in the Prior Art Database: 2005-Feb-06
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Greschner, J: AUTHOR [+2]

Abstract

By decoupling the vertical and lateral etching during the production of a lift-off mask, the required spacing between adjacent metal lines is reduced to 1 to 2 Mum.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 98% of the total text.

Page 1 of 2

Lift Off Process for Producing a Dense Metallization Pattern

By decoupling the vertical and lateral etching during the production of a lift- off mask, the required spacing between adjacent metal lines is reduced to 1 to 2 Mum.

A first resist layer 2, a lift-off barrier 3, consisting of materials, such as SiO(2), Si(3)N(4) or glass resin, and a second resist layer 4 are consecutively deposited on substrate 1. The desired pattern is transferred to resist layer 4 which serves as an etch mask when lift-off barrier 3 is structured by RIE (reactive ion etching) in a CF atmosphere. Lift off barrier 3 serves as an etch mask during the RIE of resist layer 2 in an 0(2) atmosphere at a pressure of about 2 m Torr. This process step also causes resist layer 2 to be removed. Fig. 1 is a schematic cross-sectional view of the structure existing at that stage, with opening 5 having vertical walls without any overhang.

In another RIE step, which is also implemented in an 0(2) atmosphere but at a pressure of about 100 m Torr, opening 5 is reproducibly laterally expanded by 200 to 300 nm. The enlarged opening 6 has overhanging walls, as shown in Fig.
2. If cleaning of substrate 1 is advisable, the RIE step, used to vertically etch resist layer 2, is repeated. On the lift-off mask in Fig. 2, a metal layer 7 is blanket deposited (Fig. 3). Finally, resist layer 2 and with it overlying etch barrier 3 and overlying metal layer 7 are lifted off.

1

Page 2 of 2

2

[This page contains 1 pictu...