# US 2008/0187861 A1 · Master Substrate and Method of Manufacturing a High-Density Relief Structure

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- Number: US 2008/0187861 A1
- Document ID: US20080187861A1
- Status: Published application
- Kind: A1
- Application number: 11/577,036
- Filed: 2005-10-12
- Published: 2008-08-07
- Earliest claimed: 2004-10-19
- Assignees: Koninklijke Philips Electronics N.V.
- Inventors: Erwin Rinaldo Meinders
- Web page: https://patentgrep.com/patent/US20080187861A1

## CPC

- G11B 7/261: {Preparing a master, e.g. exposing photoresist, electroforming}
- G11B 7/0901: {for track following only (G11B7/0925, G11B7/094, G11B7/0941, G11B7/0943, G11B7/0945, G11B7/0946, G11B7/0948 take precedence)}
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)

## Abstract

The present invention relates to a master substrate (10) for optical recording comprising a recording layer (12) and a substrate layer (14), the recording layer comprises a growth dominated phase-change material, the chemical properties with respect to chemical agents of which may be altered due to a phase change induced by projecting light on the recording layer. For tracking purposes, the substrate layer comprises pre-grooves (16). The present invention further relates to a method of manufacturing a stamper for replicating a high-density relief structure.

## Claims

### Claim 1

A master substrate (10) for optical recording comprising a recording layer (12) and a substrate layer (14),
the recording layer comprising a phase-change material, the properties with respect to chemical agents of which may be altered due to a phase change induced by projecting light on the recording layer, and
the substrate layer comprising a structure (16) for tracking purposes.

### Claim 2 (depends on 1)

The master substrate according to claim 1, wherein a first interface layer (18) is arranged between the recording layer and the substrate layer.

### Claim 3 (depends on 2)

The master substrate according to claim 2, wherein a second interface layer (20) is arranged between the first interface layer and the substrate layer, and the first interface layer (18) is etchable.

### Claim 4 (depends on 1)

The master substrate according to claim 1, wherein a heat-sink layer (22) is arranged between the recording layer and the substrate layer.

### Claim 5 (depends on 1)

The master substrate according to claim 1, wherein a leveling layer (24) is arranged between the recording layer and the substrate layer.

### Claim 6 (depends on 1)

The master substrate according to claim 1, wherein a reflective layer (26) is arranged between the recording layer and the substrate layer.

### Claim 7 (depends on 1)

The master substrate according to claim 1, wherein a protection layer (28) is arranged above the recording layer.

### Claim 8 (depends on 1)

The master substrate according to claim 1, wherein the structure (16) for tracking purposes comprises of a pre-groove structure.

### Claim 9

A method of manufacturing a stamper for replicating a high-density relief structure comprising the steps of:
illuminating a master substrate (10) in a conventional optical disc drive by a focused and modulated light beam, the master substrate comprising a recording layer (12) and a substrate layer (14), the recording layer comprising a phase-change material, the properties with respect to chemical agents of which may be altered due to a phase change induced by projecting light on the recording layer, and the substrate layer comprising a structure (16) for tracking purposes,
treating the previously illuminated master substrate with a solvent, thereby obtaining a relief structure (30),
depositing a metallic layer on the relief structure,
growing the deposited layer to a desired thickness, and
separating the grown layer.

### Claim 10 (depends on 9)

The method according to claim 9, wherein the step of growing the deposited layer to a desired thickness comprises electro-chemical plating.

### Claim 11 (depends on 9)

The method according to claim 9, wherein the structure for tracking purposes comprises of a pre-groove structure, and an interference pattern projected from the pre-groove structure onto a detector (132) is used for tracking.

### Claim 12 (depends on 9)

The method according to claim 9, wherein the structure for tracking purposes comprises of pre-grooves, and the light beam is deliberately placed off-track, so as to write a data pattern that is not restricted to following the pre-groove structure.

### Claim 13 (depends on 1)

A method of producing an optical data carrier using a master substrate according claim 1.