Browse Prior Art Database

Plated Metal Mask for Precise Excimer Laser Ablation of Glasses

IP.com Disclosure Number: IPCOM000122216D
Original Publication Date: 1991-Nov-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 59K

Publishing Venue

IBM

Related People

Caufield, T: AUTHOR [+3]

Abstract

Disclosed is a method for the precise fabrication of total-internal- reflection mirrors in glass optical waveguides using excimer laser ablation and a plated nickel mask.

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This is the abbreviated version, containing approximately 55% of the total text.

Plated Metal Mask for Precise Excimer Laser Ablation of Glasses

      Disclosed is a method for the precise fabrication of
total-internal- reflection mirrors in glass optical waveguides using
excimer laser ablation and a plated nickel mask.

      A common masking technique for excimer laser ablation
processing is contact masking.  Contact masking is generally done by
fabricating a metal mask (typically, molybdenum) and affixing it to
the sample to be ablated.  This is not optimal because it is
difficult to align the mask, retain alignment while the sample is
secured and/or ablated, register the mask over large areas due to
bowing, and produce features in the mask which are smaller than 1 mil
(25 mm).

      In order to fabricate total internal reflection mirrors in
(glass or polymeric) optical waveguides [*]. the position, height
above the sample, and thickness of the mask are critical.  When a
contact mask is used there is an inherent uncertainty in the height
of the mask due to uncertainty of the intimacy of contact between the
mask and the sample.  Further, the edges of the features in
molybdenum masks are not very smooth.  This edge roughness translates
directly into etched features which are rough and, therefore, optical
waveguides with increased loss.

      Here, a removable metal mask is deposited on the guides with
photolithographic accuracy.  This is done by plating a thick nickel
film through a photopatterned SU8-epoxy stencil.  This plate...