Browse Prior Art Database

Optical Storage Media with Pregrooved Substrate

IP.com Disclosure Number: IPCOM000111235D
Original Publication Date: 1994-Feb-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Bell, A: AUTHOR

Abstract

Disclosed is an improved method for etching groove patterns on optical storage media substrates.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 84% of the total text.

Optical Storage Media with Pregrooved Substrate

      Disclosed is an improved method for etching groove patterns on
optical storage media substrates.

      Directly grooved glan substrates are a leading candidate for
high performance optical storage media due to their excellent
mechanical, chemical and stability properties.  One method for
preparing such substrates utilizes photolithographic techniques.  The
glan surface is coated with a photoresist and etched to form the
groove pattern using either by wet chemical or dry (RIE) etching
method.  The recording substrate, typically magnesium-oxide layers,
is then applied.  These layers conform to the grooved surface.

      In an improved method, the glan is first coated with a layer of
silicon dioxide (i.e., quartz) of a thickness equal to the intended
groove depth.  The grooves are then etched into the SiOsub 2 layer,
the groove depth being controlled by the etch rate differential
between the SiOsub 2 layer and the surface of the underlying
substrate.  The grooved layer is then coated with an M-O layer.  This
method results in smoother grooves having more uniform depth.  But it
also requires the additional processing step of applying an extra
layer.

      The present invention improves groove quality without creating
additional processing steps by etching grooves directly into the M-O
layers.  The surface is first coated with any one of the materials
typically applied as an antireflection dielectr...