Browse Prior Art Database

Colloidal Lithography

IP.com Disclosure Number: IPCOM000112610D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

Liniger, EG: AUTHOR [+2]

Abstract

The conventional method for photolithography utilizes a photosensitive polymer (photoresist). After a coating of this polymer is produced, selected areas are exposed to light through a mask; subsequent etching with a developer either removes those regions exposed to the light or those regions that were not exposed, depending on the type of photoresist. This type of method cannot be applied to surfaces with macroscopic, 3-D features, since macroscopic smoothness is needed so that a uniform coating of photoresist can be applied, as by spin coating. Also, only certain narrow choices of polymers can be applied, namely those that have the appropriate photosensitive characteristics.

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Colloidal Lithography

      The conventional method for photolithography utilizes a
photosensitive polymer (photoresist).  After a coating of this
polymer is produced, selected areas are exposed to light through a
mask; subsequent etching with a developer either removes those
regions exposed to the light or those regions that were not exposed,
depending on the type of photoresist.  This type of method cannot be
applied to surfaces with macroscopic, 3-D features, since macroscopic
smoothness is needed so that a uniform coating of photoresist can be
applied, as by spin coating.  Also, only certain narrow choices of
polymers can be applied, namely those that have the appropriate
photosensitive characteristics.

      To avoid these problems, a new approach for laying down a thin,
patterned layer of polymeric material is disclosed that can be
applied to surfaces with macroscopic features.  Also, the types of
polymers that can be applied are much broader.

      The first step is to deposit a single layer of thermoplastic
polymeric particles 10 (latices) on a surface 12 in the desired
pattern.  This is accomplished by using a patterned molecular film of
polymeric flocculant 14 on the surface which selectively holds the
latex particles to the surface, as shown in Fig. 1.

      The second step is to heat the layer of particle 10 above their
softening point so that the particles fuse together, forming a
continuous thin layer of polymer.  With these two steps,...