Imation Corporation

Minnesota Mining and Manufacturing Company

Frank E Aspen

Jathan D Edwards

Chad R Sandstrom

Ramon F Hegel

Michael F Weber

Nang T Tran

Richard F Willson

Joseph H Sexton

James R Gilbert

Frank R Jeffrey

Padmanabham A Arimilli

Mark L Schroeder

Terry L Morkved

Mastering techniques are described that can improve the quality of a master used in data storage disk manufacturing. In particular, the techniques described herein can improve resolution of the features created on the master by reducing mastering noise. The techniques include depositing a multi-layer structure adjacent a master substrate layer. The multi-layer structure includes an etch stop layer, an etch layer, and a photoresist layer. A thickness of each of the layers is selected to generate substantially no reflectivity for at least one interface of the multi-layer structure to substantially eliminate stray light effects. The photoresist layer defines a portable conformable mask (PCM) for the etch layer. The etch layer is etched through the contact mask to define a feature of the master in the etch layer. The etch stop layer thickness may be selected to be as thin as possible to reduce surface roughness of the multi-layer structure.

Anti-reflection optical data storage disk master

In one embodiment, holographic data storage medium includes a first thermoplastic substrate portion having a thickness less than approximately 2 millimeters and a second thermoplastic substrate portion having a thickness less than approximately 2 millimeters. A holographic recording material may be sandwiched between the first and second thermoplastic substrate portions. By making thermoplastic substrate portions sufficiently thin, edge wedge problems can be avoided.

Fabrication of sandwiched construction media

Sandwich holographic disk construction with thin molded substrates

A holographic data storage medium having an anti-reflective coating is described. The anti-reflective coating can be made to reduce reflectivity for S-polarized light over a wide range of incident angles. Moreover, the anti-reflective coating can be made to have a sufficiently high transmittance for the S-polarized light. The coating may improve performance of the holographic data storage medium, and can facilitate higher storage densities than can be achieved without the coating.

Anti-reflective coating for holographic data storage media

Thermoplastic substrates for holographic data storage media

An air-incident, optical data storage medium has a substrate, a reflector layer, a magneto-optic recording layer, and a protective layer. The reflector later has at least one of an electrical conductivity greater than about 5.0&times;10,(&OHgr;-cm),, an RMS surface roughness less than about 1.0 nm as measured by atomic force microscopy, and an index of refraction of less than about 0.5 at a read wavelength.

Magneto-optical data storage disc with highly conductive, smooth reflector layer

A magneto-optic recording medium having a reduced demagnetizing field threshold incorporates a thin recording layer having a thickness of less than or equal to approximately 15 nm, and preferably less than or equal to approximately 12 nm. The recording medium thereby exhibits a demagnetizing field threshold of less than or equal to approximately 150 Oe, and preferably less than or equal to approximately 120 Oe. Dielectric and reflective layers in the recording medium stack are tuned to achieve acceptable optical and magnetic characteristics for write and readout operations. The reduced demagnetizing field facilitates use of the recording medium in recording applications that use small magnetic fields for recording and erase. The recording medium is particularly useful in near-field, air-incident recording applications employing magnetic field modulation recording techniques.

Magneto-optic recording medium with reduced demagnetizing field threshold

A light transmitting electrically conductive stacked film, useful as a light transmitting electrode, including a first light transmitting electrically conductive layer, having a first optical thickness, a second light transmitting layer, having a second optical thickness different from the optical thickness of the first layer, and an electrically conductive metallic layer interposed between and in initimate contact with the first and second layers.

Photovoltaic device having light transmitting electrically conductive

The present invention relates to novel electrophotographic imaging systems and particularly to novel electrophotographic photoreceptors. These photoreceptors comprise a conductive substrate, an inorganic barrier-charge transport layer, and a photoconductive insulative layer. The barrier charge transport layer comprises aluminum oxide having a non-porous zone adjacent the substrate, and a porous charge transport zone.

Growing community of inventors

Saint Paul, MN, United States of America

Frank E Aspen