thin Film Head Fabrication In The Pmr Era - Idema · Thin Film Head Fabrication in the PMR Era ... Areal density growth & slider form factor ... stripe height & throat height control

Thin Film Head Fabrication in the PMR Era

Ajit ParanjpeVeeco Data Storage Technology

IDEMA PMR SymposiumDec. 7, 2006

©2006 Veeco Instruments Inc.

Outline

Thin Film Head Technology DriversAreal density growth & slider form factorPMR roadmap & architectural trends

Wafer Processing for PMRPerpendicular write-pole depositionPerpendicular write-pole definition

Slider Processing for PMRShape, stripe height & throat height controlFly-height & head media spacing reduction

Summary of Process Solutions

Equipment & Metrology Enablers

Thin Film Head Technology Drivers


Market Drivers

CE and SFF HDD growth is

driving areal density growth

Rapid adoption of PMR for high

capacity SFF Drives


Areal Density Growth

Source: HGST, Diskcon 2006

PMR technology now mainstream to maintain 40% CAGR


Multiple Technology Transitions

Concurrent AdoptionPMR, TMR & Femto Sliders

Areal Density Growth125 500 Gb/in2

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2005 2006 2007 2008 2009 2010

Year

Ado

ptio

n [%

]

0

100

200

300

400

500

600

700

800

900

1000

GB

its/in

2

PMR

Areal Density

TMR

CPP-GMR

Femto

Femto, PMR and TMR place new demands on process equipment


PMR Roadmap

Parameter 2006 2007 2008 2009Areal Density (Gb/in2) 125 175 245 350Track Width (nm) 115 100 80 65High Bs Pole Plating / Laminated Damascene / LaminatedThroat Height (nm) 100 90 75 60Stripe Height (nm) 120 100 90 70Magnetic Spacing (nm) 20 18 15 12DLC Thickness (nm) 2.4 2.0 1.7 1.5

Height Control σ (nm) 8 7 6 5PTR / PTP σ (nm) 0.6 0.5 0.4 0.4

Shrinking geometries & tightening control requirements


Perpendicular Writer Options

SpartanCusp Trail

Floating Front Shield Front Shielded Wrapped

Field & field gradient tradeoffs guide selection

HAMR

SMT Oscillator

Mr

Perpendicular Write Pole Front Shield

Biasing magnet

Rf Assist – Prof J. Zhu

Source: Mao & Murdock, Seagate

Increasing process complexity

Perpendicular Write-Pole Formation


Write-Pole Requirements

PMR Write-Pole

Decreased track-width Narrower pole width

High coercivity media High Bs (> 2.4T) materials

Side track erasure Tapered pole shape

Reduced remnant erasure Laminated stack


Evolution of Write-Pole Formation

Method I

Method II

Al2O3 or DLC Hard Mask

Laminated PVD Pole

PR

RIBE Hard Mask Etch IBE

Pole Etch

PR

Plate PoleIBE

Trapezoidal PoleSlimming

RIBE Trapezoidal Trench Etch

IBEHard Mask Etch

RIBE Hard Mask

CMP Stop Layer

Deposit Pole CMP

Al2O3

Method III

RIBE Stop Layer


High Moment Stack for Write-Pole

RF Mag.

Cathode

Multi-target planetary PVD tool for laminates Velocity profiling uniformity < 1% (3σ) & ~0.02 nm controlUpto 13 sputtering targets & ion beam assistHigh throughput, low CoO architecture

Cathode

Ion

Sou

rce

Target

Chim

ney

Substrate


Bilayer & Multi-layer Write Pole Stacks

CoFe70250Å/Ru (Cr)/CoFe70250Å

-150

-100

-50

0

50

100

150

-500 -250 0 250 500H (Oe)

m/m

s (%

)

EasyHard

CoFe/Ru/CoFe

-500 -250 0 250 500H (Oe)

EasyHard

CoFe/Cr/CoFe


-150

-100

-50

0

50

100

150

-500 -250 0 250 500H (Oe)

m/m

s (%

)

EasyHard

CoFe/Ru/CoFe

-500 -250 0 250 500H (Oe)

EasyHard

CoFe/Cr/CoFe


-150

-100

-50

0

50

100

150

-500 -250 0 250 500H (Oe)

m/m

s (%

)

EasyHard

CoFe/Ru/CoFe

-500 -250 0 250 500H (Oe)

EasyHard

CoFe/Cr/CoFe

800

0

0.5

1

1.5

2

2.5

4 5 6 7 8 9 10 11 12

t (Å)

σ (e

rg/c

m2 )

Cr

Ru

800

0

0.5

1

1.5

2

2.5

4 5 6 7 8 9 10 11 12

t (Å)

σ (e

rg/c

m2 )

Cr

Ru

NiFe25Å/{[CoFe50350Å]m/Ru8.5Å}n-1/ [CoFe50350Å]m/NiFe25Å/Ru20Å

-4.5

-3

-1.5

0

1.5

3

4.5

-100 -50 0 50 100H (Oe)

m (e

mu)

v

m=4n=2

-100 -50 0 50 100

H (Oe)

m=2n=4

-400 -200 0 200 400H (Oe)

m=1n=8

NiFe25Å/{[CoFe50350Å]m/Ru8.5Å}n-1/ [CoFe50350Å]m/NiFe25Å/Ru20Å

-4.5

-3

-1.5

0

1.5

3

4.5

-100 -50 0 50 100H (Oe)

m (e

mu)

v

m=4n=2

-100 -50 0 50 100

H (Oe)

m=2n=4

Hce = 8.3 Oe

Bre/Bse = 0

Hk = 30 Oe

Hch = 1.8 Oe

Brh/Bsh = 0.06

Hex = 10.8 Oe-400 -200 0 200 400

H (Oe)

m=1n=8

-4.5

-3

-1.5

0

1.5

3

4.5

-100 -50 0 50 100H (Oe)

m (e

mu)

v

m=4n=2

-100 -50 0 50 100

H (Oe)

m=2n=4

-400 -200 0 200 400H (Oe)

m=1n=8


IBE for Perpendicular Write-Pole Formation

IBE for trapezoidal slimmingControllable side-wall angle ~ 8 – 10o from normal

Multi-angle etch processStatic and sweep etch

CD uniformityLow beam divergence and steering angle

RIBE process for hard mask etchSelectivity of Alumina : pole materialVertical sidewalls

RIBE process for trench formationSelectivity of Alumina : mask material & Alumina : stop material


Sidewall Symmetry & CD ControlBeam Collimation – Divergence & Steering

Beam DivergenceM axim um Angle

Beam Steering Angle

Three GreedBeam let opticsV p(r)

np(r)

V b(r)

zr Φ

Beam Steering impacts glancing angleStatic Etch & CD Etch Uniformity

Uniformity of Beam Divergence impacts CD Etch Uniformity

Φp(r )

Beam Divergence impacts CD Etch Profile

High etch rate

Low etch rate

Symmetric

Asymmetric


Nexus 420 for Pole Etch

Collimated ion sourceLow divergence & steering angles

Improved etch uniformity & CD control (< 2.5 % ∆CD)

PBN HE-ANC

RF MATCHBOX RF PS

HV PS

0.0 0.5 1.0 1.5 2.0 2.5 3.00

1

2

3

4

5

Sample #9242002-1

Ibeam = 650 mAUbeam = 1200 VUsuppressor = -300V

Beam

Div

erge

nce

(o )

Radial distance (inch)

5%10%

Divergence angle of 2.4 +/- 0.3degrees across 6” diameter

Divergence

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0 0.5 1 1.5 2 2.5 3 3.5

Wafer Radius (inches)

Ste

erin

g A

ngle

(deg

rees

)

1200V1000V

Steering

Beam steering < 0.5º

PBN HE-ANC

RF MATCHBOX RF PS

HV PS

Nexus 420Ion Source


Intermediate Energy Pole Process

Pole process at 600 to 800 V regime developedSimilar uniformity and divergenceEtch rate 80 - 90% of high rate process

0.0

1.0

2.0

3.0

4.0

5.0

6.0

100 200 300 400 500 600 700 800 900 1000 1100 1200 1300Beam Energy [V]

Div

erge

nce

Ang

le

Typical NEXUS 420Sensor Etch

Typical NEXUS 420Pole Etch

New Lower Energy Pole Process

0123456789

100 200 300 400 500 600 700 800 900 1000 1100 1200 1300Beam Energy [V]

Uni

form

ity (3

sigm

a%) 0 deg static

0 deg rotated

Divergence

Uniformity


RIBE for Trench or Hard Mask Etch

Developed CHF3 based RIBE processER of Al2O3 : NiFe > 7:1 ER of Al2O3 : NiCr > 10:1Selectivity over full angle range

0

2

4

6

8

10

12

14

16

18

0 10 20 30 40 50 60 70

Fixture Angle

Sele

ctiv

ity A

l2O

3 : M

etal

NiCr

NiFe

FeCo

Ta

0

5

10

15

20

0 20 40 60 80% CHF3

ER (A

l2O

3) /

ER (M

etal

)

NiCr

NiFe

FeCo

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

0 20 40 60 80% CHF3

ER (A

l2O

3) /

ER (M

etal

)

Ta

Ru


PMR Pole Monitoring

FIB-SEM cross-section

Advanced writerstructure

Veeco x3D AFM


PMR Pole Production Monitoring

pinching

ABS plane

High Resolution (10 nm spacing) Line Width Variability

20

25

30

35

40

45

50

0 200 400 600 800 1000

Position Along Line (nm)

Line

Wid

th (n

m)

Scan1Scan2

Nominal 28 nm

Nominal 43 nm

500 nm range

Plan view

x3D Imaging Technology

•High Lateral Resolution• 3D Monitoring

• Line Edge Roughness• Pole Pinching & Narrowing• Photoresist Profile

• High Throughput• Non Destructive

narrowing

X-section

Slider Processes for PMR


Slider Process Challenges for PMR

Rough & Fine

Lap

ABS Pattern & Etch

Kiss Lap

Slice

DLC

02468

101214161820

Yie

ld L

oss

(%

)

Lapping Sawing Other

Shape Control•Straightness•Perpendicularity•Rowbar bow•Pullouts

Performance MetricsFly height, stiction

Yield MetricsThroat & stripe

height, PTR, debris

~ 40% total

Dice

Head Performance•Stripe height•Throat height•PTR•Sensor smearing

Head Media Spacing•PTR•Crown & camber

Head Media Spacing•Ultra-thin defect-free coating

Flyheight Control•Triple cavity etch•Cavity shape•CD & depth

Defects•Pressure ridges•Debris•Pullouts


Slicing, Lapping & Dicing for PMR

ABS

Backside grind sets Perpendicularity

between the ABS & overcoat

θ

µ-radian Angle Adjustment Control Technology provides

Reader/Writer Offset

Low lapping pressure improves Flatness,

Surface Finish and PTR

Sensor Height Control Technology provides

Stripe Height Control

Dual-pass dice manages dice edge stress &

Particles

Double Sided Machining Process to reduce row bar stress

Wedge angle control provides

Parallelism


Grind & Slice for Shape Control

90 ±0.1°

EDG

E GR

IND

WH

EEL

90°

15 µm

65 – 75 µm

Thin blade deflects during slicingSolution:

Edge grind backside of rowbar for perpendicularityEstablishes reference for subsequent processing


Stripe & Throat Height Control for PMR

Reader & writer ELG feedback for height controlWedge angle control for parallelism

ROW IS MICRO-ADJUSTED BY ELG LAPPER UNTIL ABS IS PARALLEL WITH ROW TOOL

θ

Plate

SliderGlue Line

Row Tool

Variable Plate Run-out,Shape, Arm Square

Slider

Row Tool

Gb/in2 Stripe Height (nm)

Stripe Height 1σ (nm)

Throat Height 1σ (nm)

Perpendi-cularity

120 150 7.5 20 ±0.375o

240 70 3.5 10 ±0.15o


Overcoat Thickness Reduction

Reduce VariabilityCarbon and Si

WIW 2-3 1.5 ÅRTR 4-5 2.5 Å

Pre-cleanUniform etching

Improve pre-clean process

Reduce sensor recession1.5 nm < 1 nm

Reduce Si/Carbon Thickness

10 Å Si/10 Å C 13 Åtotal

∆ = -5 to 8 ÅDual Source FCA

∆ = -4 Å• Improved in-situ thickness

monitoring• Pulsed FCA source• Long-throw PVD Silicon

∆ = - 5 to 10 ÅTunable Low Energy ion source

Interface Control Module

∆ in HMS -15 Å


Low Energy Ion Beam Etching

Etch Profile for Different Tilt Angles Ub=100V, Ib=150mA, Us=700V

1000

1500

2000

2500

3000

3500

4000

4500

-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6R, inch

Etch

Dep

th [A

]

0 deg (1.9%)

-35 deg (2.1%)

-55 deg (1.5%)

-75 deg (1.8%)

CPP sensor smear removal & ABS smoothening with controlled PTR & uniformity


Pulsed FCA ta-C Film Properties

Precise control of film thicknessLinearly dependent on number of pulses

Film density ~2.95 - 3.03 g/cm3

Higher than DC FCA ~ 2.8 g/cm3

Optical properties (n, k) are similar to DC FCAFilms have the same microstructure

Film stress -4 to -6 GPa (~ 25 nm DLC)Similar to DC FCA

Particulate levels are similar to DC FCAUniformity < 5% 3σ

Shape the plume with focusing / deflection coils


ta-C Uniformity Tuning Plasma Beam Shaping/ Deflection

I dfl at PS2/PS3=2.5/2.5 Amp, 750V, 1000 pls

02468

1012141618

-5 -4 -3 -2 -1 0 1 2 3 4 5Radius (Inch)

Thic

knes

s [A

ng]

Idfl=0Idfl=2AmpIdfl=3Amp

Concave

Convex

Deposition Profile Optimization By Beam Shaping

Source conditions: 1000 pulses, focusing coils -2.5A.20% loss in dep. rate when tuning uniformity due to offsetting the plume

Deflection Current [A]

Uniformity +/- %

0 13.8 %

2 6.6 %

3 13.3 %


PFCA Uniformity: ~2A Range

PFCA Thickness Profiles. Runs #092506-1-10

5

10

15

20

0 1 2 3 4 5

Radius [inch]

Thic

knes

s [A

]

092506-01

092506-02092506-03092506-04

092506-05092506-06092506-07

092506-08092506-09

092506-10

WIW UniformityRange: ~2A

PFCA FilmsTx Repeatability, Runs #092506-1-10

15

16

17

18

19

20

1 2 3 4 5 6 7 8 9 10

Run #

Avg

. Tx

[A]

RTR UniformityRange: ~0.5A


Next Generation Overcoat ToolOverall System Configuration

Pre-Clean Module

Deposition Module

Separate modules for pre-clean and deposition processes


AFM PTR Monitoring

• Proven Automated PTR Measurements• Automated Tip Exchange*

•Flat XY Scanner• < 2 nm Leveling Error over 100 µm• Improved GR&R to < 0.15 nm 1σ• Throughput improvement > 30%

• Optimized Data Storage Performance• Magnetic Force Microscopy

* PatentedVeeco Vx200-PTR

AFM PTR MFM ImageLeveling Error < 2 nm


HD

8100Optical PTR Monitoring

y = -0.0394x + 2.6

y = -0.0047x + 7.1666

-15

-10

-5

0

5

10

15

0 20 40 60 80 100 120

Y Position (µm)

Z H

eigh

t (nm

)

AlTiCP1S1

PTR

P1-ALU

P1S1

ALU

P1-ALU

PTR

AlTiC

Uncompensated Dual AccuPhaseCompensated

97.72%

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

-4 -3 -2 -1 0 1

Pro

ba

bili

ty D

en

sity

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1.1

Cu

mu

lati

ve

Pro

ba

bili

ty

99.34%

0

0.2

0.4

0.6

0.8

1

1.2

-3 -2 -1 0 1

Pro

ba

bili

ty D

en

sity

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1.1C

um

ula

tiv

e P

rob

ab

ility

• High Speed PTR @ < 6 Sec/Site• Improved Accuracy Through Compensation

•> 20% Yield Enhancement• Optical Solution for AFM Monitoring

2.28% Protrusion

0.66% Protrusion

•Less Scrap•Tighter Control•Higher Yields

y = 0.9931x + 0.107R2 = 0.8761

-6

-5

-4

-3

-2

-1

0

-6 -5 -4 -3 -2 -1 0

AFM PTR (nm)

PSI P

TR (n

m)

AFM toOptical

Correlation


Air Bearing Etch: Background

Advanced ABS must provide:Small and stable spacing between slider and disk

High air-bearing stiffness

Low sensitivity of spacing on disk velocity and skew angle

Low sensitivity of flying behavior (attitude)

Negative pressure pocketTri-pad designsMultiple etch depths

Cavity > 1 - 2 µmShallow ~ 1 - 200 nmSuper Shallow ~ 20 nm

Stringent uniformity, shape, depth & CD control requirements

cavityshallow

* Source: Hitachi GST* Source: UCSD-CMRR


NEXUS® Slider IBE Systems OverviewApplication Configurable Product Line

NEXUS® 420SiApplication: Shallow & Super Shallow Step

Improved Etch Depth Control

NEXUS® 350SiApplication: Cavity and Shallow

Process Matching with RF-350S

Field Upgradeable to 420Si

NEXUS® 350SEApplication: Deep Cavity and Cavity

Low COO, High Throughput, Small Footprint

TEC fixture

RIE Replacement Tool

> 2µ

m

< 3

000

Å


NEXUS 420Si Process PerformanceTypical Etch Profiles

Increased Device Yield Through Improved Etch Depth ControlRotated WIW Etch Uniformity < 2.0%, 3σRTR Uniformity: < 2.0%, 3σWide process window

-45 Degrees Rotated

230

235

240

245

250

255

260

-150 -100 -50 0 50 100 150

Distance from Center (mm)

SiO

2 Etc

h Ra

te (A

/min

)

600Vb/230Ib/-150Vs-45 Degrees Rotated

420

430

440

450

460

-150 -100 -50 0 50 100 150


SiO

2 Etc

h R

ate

(A/m

in)

Unif. Over 267mm H-L Unif. = 0.9% 3sig Unif. = 1.4%

Uniformity over 225mm H-L Unif. = 0.7% 3sig Unif. = 1.3%

800.1Vb/350Ib/-200Vs

-60 Degrees Rotated

680

690

700

710

720

730

740

750

760

770

780

-150 -100 -50 0 50 100 150


SiO

2 Etc

h R

ate

(A/m

in)



1000.2Vb/490Ib/-250Vs-45 Degrees Rotated

920

930

940

950

960

970

980

990

1000

1010

1020

-150 -100 -50 0 50 100 150


SiO

2 Etc

h R

ate

(A/m

in)



1200.2Vb/650Ib/-300Vs

225mm Diameter 225mm Diameter

225mm Diameter

9” 1.3% 3σ10.5” 1.6% 3σ

9” 1.3% 3σ10.5” 1.4% 3σ

9” 1.1% 3σ10.5” 1.1% 3σ

9” 1.5% 3σ10.5” 1.4% 3σ

225mm Diameter

600V -45º 800V -45º

1000V -60º 1200V -45º

-45 Degrees Rotated

230

235

240

245

250

255

260

-150 -100 -50 0 50 100 150


SiO

2 Etc

h Ra

te (A

/min

)

600Vb/230Ib/-150Vs-45 Degrees Rotated

420

430

440

450

460

-150 -100 -50 0 50 100 150


SiO

2 Etc

h R

ate

(A/m

in)



800.1Vb/350Ib/-200Vs

-60 Degrees Rotated

680

690

700

710

720

730

740

750

760

770

780

-150 -100 -50 0 50 100 150


SiO

2 Etc

h R

ate

(A/m

in)



1000.2Vb/490Ib/-250Vs-45 Degrees Rotated

920

930

940

950

960

970

980

990

1000

1010

1020

-150 -100 -50 0 50 100 150


SiO

2 Etc

h R

ate

(A/m

in)



1200.2Vb/650Ib/-300Vs

225mm Diameter 225mm Diameter

225mm Diameter

9” 1.3% 3σ10.5” 1.6% 3σ

9” 1.3% 3σ10.5” 1.4% 3σ

9” 1.1% 3σ10.5” 1.1% 3σ

9” 1.5% 3σ10.5” 1.4% 3σ

225mm Diameter

600V -45º 800V -45º

1000V -60º 1200V -45º


ABS Metrology

• Critical to Fly-Height Control• Slider Flatness • Local Flatness Deviations• Slider Waviness• Etch Step Sizes• Trailing Edge Roll-off

Veeco HD8100

Source: HitachiGST Web Site.


2X Dicing for PMR

• Soft cutting action of polish blade removes chips and pits along outer slider walls and 99% of pressure ridges

•• Soft cutting Soft cutting action of polish action of polish blade removes blade removes chips and pits chips and pits along outer slider along outer slider walls and 99% of walls and 99% of pressure ridgespressure ridges

• Pressure ridges created as face of harder blade enters ABS side of slider

•• Pressure ridges Pressure ridges created as face of created as face of harder blade enters harder blade enters ABS side of sliderABS side of slider

1X DICEHard blade3 - 4 nm Ra5 µm chipping

1X DICE1X DICEHard bladeHard blade3 3 -- 4 nm R4 nm Raa55 µµm chippingm chipping

2X DICESoft blade1 - 2 nm Ra1 µm chipping

2X DICE2X DICESoft bladeSoft blade1 1 -- 2 nm R2 nm Raa11 µµm chippingm chipping


Process Solutions For the PMR Age

Manufacturing Step Process SystemSensor Deposition High ratio TMR Nexus-MT

Sensor Etch Highly Uniform Collimated Etching Nexus 420

Isolation Layer Deposition High quality alumina filmsNexus IBD-DS / Nexus ALD

Overcoat Deposition Pulsed FCA with Interface Control for thin overcoats Nexus DLC-X

Hard Bias Deposition Collimated Deposition for lift-off Nexus IBD-DS

Write Pole Deposition High Moment Laminated Poles Nexus-MT

ABS Etch Shallow/Cavity/Deep Cavity for low fly heights

Nexus 350Se/420Si

Slider Formation 2X Dicing Process for reduced particulates ADS160

Write Pole Shape High Collimation Etching with good CD control Nexus 420

Rowbar Formation

Lapping

Grinding the backside of the row for pependicularity ADS160gs

ASL200Wedge angle control, µ-radian angle adjustment control for parallelism


Veeco Process Solutions For PMR

Sub 20 Å overcoat for low HMS

Sub 100nm shallow step for low HMS

Shallow & deep cavity etch

Asymmetry control for narrow TW

CD control for PMR and Sensor Etch

TMR/CPP & HMM

Isolation, and seed for TMR & PMR Alumina and

metal layers

Slice, grind & dice

Rough, fine & kiss lap

SliderWafer


Metrology Solutions for the PMR Age

Manufacturing Step Metrology System

Write Pole Shape Pole Critical Dimensions X3D

Wafer test Read pole magneto-resistance

QSW3000

Rowbar lapping PTR control / monitor HD8100

Vx200 PTR

DLC deposition PTR control / monitorHD8100

Vx200 PTR

ABS EtchEtch depth

Rowbar shapeHD8100

Slider Formation Slider shape HD8100

HSA Suspension shapeSAT probeHD8100

Veeco Provides Metrology Solutions for each process step …..

x3D AFM

HD8100Vx200-PTR

QSW

Gen

III


Veeco Metrology Solutions for PMR

LateralDimension

Veeco’s Unique Position… METROLOGY APPLICATIONS

Suspension Suspension ShapeShape

Silicon Atom0.2nm dia

Nan

otec

h

1,000,000nm

100,000nm

10,000nm

1,000nm

100nm

10nm

1nm

0.1nm

Mic

rote

ch

Optical Industrial

Auto AFM

HD OpticalProfiler

Vx200-PTR

x3D Pole Monitor

ABS Surface ABS Surface Shape, CavityShape, Cavity

NanoBio Research AFM

Dimension 3100 / 5000

SAT Probe

RTIQSW

Dektak 10 mm

PMR Width CDPMR Width CD

80nm

1 mm

Pole Tip Pole Tip Recession Recession

(PTR)(PTR)

2 nm


Acknowledgments

Adrian DevasahayamMeng LeeBill AbeytaJohn WissingerMichael Peters

Thanks for your attention!Thanks for your attention!

Documents

thin Film Head Fabrication In The Pmr Era - Idema · Thin Film Head Fabrication in the PMR Era ... Areal density growth & slider form factor ... stripe height & throat height control