Browse Prior Art Database

Method to Incorporate Three Sets Pattern Information in Two Photo- Steps

IP.com Disclosure Number: IPCOM000099218D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-14
Document File: 2 page(s) / 74K

Publishing Venue

IBM

Related People

Cronin, JE: AUTHOR [+2]

Abstract

By hardening a first image in a first photoresist layer and just developing a second image in a thicker PR layer, coincident openings in the two PR layers a first pattern. Oxygen ion etching is then used to portions of the first layer of photoresist which are by the second photoresist layer, thus a second pattern. Blanket exposing and developing all of the remaining second photoresist provides a pattern. Thus, three patterns are created having an tolerance of a single alignment. Useful include creating three different thicknesses of patterns within one level of dielectric material.

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Method to Incorporate Three Sets Pattern Information in Two Photo- Steps

       By hardening a first image in a first photoresist layer
and just developing a second image in a thicker PR layer, coincident
openings in the two PR layers a first pattern.  Oxygen ion etching is
then used to portions of the first layer of photoresist which are by
the second photoresist layer, thus a second pattern.  Blanket
exposing and developing all of the remaining second photoresist
provides a pattern.  Thus, three patterns are created having an
tolerance of a single alignment.  Useful include creating three
different thicknesses of patterns within one level of dielectric
material.

      Referring to Fig. 1, a first photoresist layer 2 is on
substrate 4.  Openings having width A and width are formed in
photoresist 2 by exposure to a first mask development.  Remaining
photoresist 2 is then hardened, by a heat treatment.  Next,
photoresist 6 is applied exposed to a second mask whereupon an
opening having C is created by exposure and development.  A pattern
by coincidence of openings having width A and C (D) then be etched in
substrate 4.  The pattern having width could be a via hole in a
dielectric substrate 4 for a interconnection.

      Referring to Fig. 2, a reactive oxygen ion etching is used to
remove all of photoresist 2 which is not by photoresist 6 while an
inconsequential amount of 6 is also removed.  There is then an
unprotected of substrate 4 having width C...