# US 7,743,487 B2 · Method to planarize perpendicular write poles using a combination of CMP and reactive ion milling

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- Number: US 7,743,487 B2
- Document ID: US7743487B2
- Status: Granted
- Kind: B2
- Application number: 11/453,681
- Filed: 2006-06-14
- Published: 2006-10-19
- Granted: 2010-06-29
- Earliest claimed: 2004-03-02
- Assignees: Hitachi Global Storage Technologies Netherlands B.V.
- Inventors: Amanda Baer; Hamid Balamane; Michael Feldbaum; Ming Jiang; Aron Pentek; Neil Leslie Robertson; Sue Siyang Zhang
- Web page: https://patentgrep.com/patent/US7743487B2

## CPC

- G11B 5/3163: {Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic layers}
- G11B 5/1278: {specially adapted for magnetisations perpendicular to the surface of the record carrier}
- G11B 5/1871: {Shaping or contouring of the transducing or guiding surface}
- G11B 5/3169: {Working or finishing the interfacing surface of heads, e.g. lapping of heads}
- Y10T 29/49032: Fabricating head structure or component thereof
- Y10T 29/49039: with dual gap materials
- Y10T 29/49046: with etching or machining of magnetic material
- Y10T 29/49048: Machining magnetic material [e.g., grinding, etching, polishing]
- Y10T 29/49052: by etching
- 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)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A perpendicular write head includes a beveled main pole having corners defining a track width and having a planarized surface and encapsulated on either side thereof and below by an alumina layer, the alumina layer having a polished surface and extending above the main pole on either side thereof as steps.

## Claims

### Claim 1

A method of manufacturing a perpendicular write head comprising:
forming a mill mask upon a laminate layer;
depositing a first hark mask upon the mill mask;
depositing a second hard mask upon the first hard mask;
depositing a third hard mask upon the second hard mask;
depositing a photoresist layer upon the third hard mask;
removing the photoresist layer and the third hard mask;
removing the second hard mask;
milling the mill mask and the first hard mask to form a beveled main pole;
depositing alumina on top of and around the beveled main pole to encapsulate the beveled main pole;
polishing the deposited alumina to a level above the mill mask;
milling the polished alumina to expose a portion of the mill mask; and
removing the first hard mask and the mill mask.

### Claim 2 (depends on 1)

The method of manufacturing a perpendicular write head, as recited in claim 1, wherein the mill mask is made of a diamond-like carbon layer or an Al2O3 layer.

### Claim 3 (depends on 1)

The method of manufacturing a perpendicular write head, as recited in claim 1, wherein a thickness of the mill mask is within a range 10-80 nanometers.

### Claim 4 (depends on 1)

The method of manufacturing a perpendicular write head, as recited in claim 1, wherein the first hard mask is made of a polyimide layer.

### Claim 5 (depends on 1)

The method of manufacturing a perpendicular write head, as recited in claim 1, wherein a thickness of the first hard mask is within a range 500-1500 nanometers.

### Claim 6 (depends on 1)

The A method of manufacturing a perpendicular write head, as recited in claim 1, wherein the second hard mask is made of a SiO2 layer.

### Claim 7 (depends on 1)

The method of manufacturing a perpendicular write head, as recited in claim 1, wherein a thickness of the second hard mask is within a range 50-150 nanometers.

### Claim 8 (depends on 1)

The method of manufacturing a perpendicular write head, as recited in claim 1, wherein the third hard mask is made of a polyimide layer.

### Claim 9 (depends on 1)

The A method of manufacturing a perpendicular write head, as recited in claim 1, wherein a thickness of the third hard mask is within a range 20-120 nanometers.

### Claim 10 (depends on 1)

The method of manufacturing a perpendicular write head, as recited in claim 1, wherein a thickness of the photoresist layer is within a range 100-250 nanometers.

### Claim 11 (depends on 1)

The method of manufacturing a perpendicular write head, as recited in claim 1, further comprising a step of reactive ion milling to remove the photoresist layer and the third hard mask.

### Claim 12 (depends on 1)

The method of manufacturing a perpendicular write head, as recited in claim 1, further comprising a step of milling to remove the second hard mask.

### Claim 13 (depends on 1)

The method of manufacturing a perpendicular write head, as recited in claim 1, wherein the deposited alumina is within range 1.5-2 microns.

### Claim 14 (depends on 1)

The method of manufacturing a perpendicular write head, as recited in claim 1, wherein the polishing step includes chemical mechanical polishing.

### Claim 15 (depends on 1)

The method of manufacturing a perpendicular write head, as recited in claim 1, wherein the milling the polished alumina step includes reactive ion milling.

### Claim 16 (depends on 15)

The method of manufacturing a perpendicular write head, as recited in claim 15, wherein the reactive ion milling is performed in a flourine-based chemisty.

### Claim 17 (depends on 1)

The method of manufacturing a perpendicular write head, as recited in claim 1, wherein the removing the first hard mask step includes reactive ion etching.

### Claim 18 (depends on 17)

The method of manufacturing a perpendicular write head, as recited in claim 17, wherein the reactive ion etching is performed in an O2-based chemistry.

### Claim 19 (depends on 1)

The method of manufacturing a perpendicular write head, as recited in claim 1, wherein after the alumina is deposited, the alumina that is on top of the beveled main pole is thicker than the alumina that is on either side of the beveled main pole.