Browse Prior Art Database

Simplified Method of Preparing Nanostructure Films

IP.com Disclosure Number: IPCOM000103461D
Original Publication Date: 1990-Nov-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 1 page(s) / 55K

Publishing Venue

IBM

Related People

Brady, MJ: AUTHOR [+4]

Abstract

Currently, "lift-off" processing utilizes directional and low pressure evaporation techniques such as e-beam evaporation and resistive heating evaporation. One of the constraints on the lift-off technique is that the mask material must be easily removed after deposition. To achieve this, the side walls of the mask (usually an organic stencil) must not be coated with the material during the deposition. This is usually the case with directional techniques which provide point sources due to large substrate to source distances. In addition, the masking material should not be subjected to any degradation.

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Simplified Method of Preparing Nanostructure Films

      Currently,  "lift-off"  processing   utilizes directional and
low pressure  evaporation  techniques  such  as  e-beam evaporation
and  resistive heating evaporation.  One of the constraints on the
lift-off  technique  is  that  the  mask material must be easily
removed after deposition. To achieve this,  the  side walls  of  the
mask  (usually  an organic stencil) must not be coated with  the
material  during  the deposition.  This  is usually  the  case  with
directional techniques  which  provide point  sources  due   to
large substrate to source distances.  In addition, the masking
material should not be subjected to any degradation.

      The above constraints preclude sputtering as a method of
deposition of materials since it is generally a conformal process
(i.e., providing a uniform coating everywhere including the sidewalls
of the mask). Further, there is generally a degradation of the
stencil in some plasmas due to energetic  particle bombardment and
the proximity of the substrate relative to the sputtering target.
Given the criteria for lift-off processing in the last paragraph, it
appears that sputtering of thin films is not compatible with these
requirements and hence, has been avoided.

      Disclosed is an experimental result that is totally unexpected.
Using a single level PMMA resist stencil, with a thickness on the
order of 100 nm, an Electron  Beam...