Table III.1 – Comparison between the Ion beam and magnetron sputtering deposition processes.

Ion Beam deposition

Magnetron sputtering (RF or DC)

Deposition rate Very low-low 0.1-1.5 Å/s

low-very high 0.5-40 Å/s

Film thickness control and uniformity

Very good

Dynamic: Good Static: good for small substrates

Film stoichiometry Good Good Sample heating Very low Dynamic: medium

Static: medium-high Process pressure

[Torr] 10-4 to 10-5 10-2 to 10-3

Disturbance of magnetic alignment

No Depends on target lifetime and on target-substrate separation

Electrical field influence

Low, no direct ion bombardment

Moderate

Film surface Smooth Depends on previous structure Film stress Low high

Deposition angle Controllable Fixed Process parameters Can be controlled

individually Cannot be independently changed

IBD PVD

IBD Reactive deposition

0 6 12 18

102

103

104

105

106

107

108

109

insulatorhigh resistivitymetal

Pure Ta: 154 .cm

Ta(N) films deposited by IBD

film

res

istiv

ity [

.cm

]

Nitrogen flow [sccm]

Dielectric characterizationTable III.9 – Properties of Al2O3 films deposited in the IBD system. IBD Al2O3 Deposition conditions

Deposition gun: 33 mA, 1sccm Xe V+=1450V, V-=-300V

Deposition neutralizer ON Assist gun: 10 sccm Ar-15%O2, no plasma

Breakdown voltage 2.3-3.6 106 V/cm step coverage 58% lateral step coverage refractive index 1.68 deposition rate 7 Å/min thickness loss in 10%HF solution 560 Å/min

400 800 1200 1600 2000

1.63

1.64

1.65

1.66

1.67

1.68

1.69

refr

activ

e in

dex,

n

Al2O3 thickness (Å)

Refractive index1.68 ~ saphire

1.5 mm CoZrNb

Al2O3 film, 1500 Å

600 Å NiFe1 A

VI

1.5 mm CoZrNb

Al2O3 film, 1500 Å

600 Å NiFe1 A

VIDielectric breakdown voltage dependence on:- oxide thickness- contact area

Composition analysis: metal contamination, stoichiometry (Al:O)

Rutherford Backscattering analysis of a IBD deposited Al2O3 film. Total level of metal

contamination < 400ppm

Film stress, adhesion

5 m AlN film delamination after disk head slider fabrication.

5 m sputtered AlN

Dual-Stripe disk headINESC (1998)

Vacuum systems

Nordiko 3600 IBD system donation from Seagate (Ireland)

CASSETTE

SUBSTRATE TABLE

HOME

Rotary pumps Turbomolecular pumps Cryogenic pumps

- 1st stage pumps- ultimate pressure ~10-4 Torr- Requires a purge vapor line

- 2nd stage pumps- ultimate pressure ~10-10 Torr- requires a backing pump

- 2nd stage pumps- ultimate pressure ~10-11 Torr

Momentum transfer from the disks to the gas molecules.Separation rotor to disks ~ free mean path (molecular regime)

0 50 100 150 200 250 300

10-710-610-510-410-310-210-1100101102

time [minutes]

Load

lock

pre

ssur

e [T

orr]

0 5 10 15 20 2510-610-510-410

-310

-210

-110

010

110

2

transfer pressure

0 1 2 3 4 5

10-8

10-7

10-6

10-5 only turbo onlycryo turbo+cryo

B.P. ~ 5x10-8 Torr

time [days]

Cha

mbe

r pr

essu

re [T

orr]

Pressure increase lower filament temperature Lower resistance

Ultimate pressure detection ~10-11 TorrUltimate pressure

detection ~10-7 Torr

Ultimate pressure detection ~10-4 Torr

Bibliography

-Nanoelectronics and information technology – Advanced Electronic Materials and Novel Devices , Chap.8, Rainer Waser (Ed.), Wiley-VCH (2003)

- VLSI Technology, S.M.Sze, McGraw-Hill International Editions

- Sputtering: user reference guide – Nordiko internal report

- Spin Electronics - Chap.13, M.Ziese and M.J.Thornton (Ed.), Lecture Notes in Physics, Springer-Verlag

-Tecnologia de Vácuo, A.M.C.Moutinho, M.E.F.Silva, M.A.Cunha, Univ.Nova de Lisboa (Ed.)

- Solid State Technology, p.35-40, January 2003

-M.Tan, “Ion beam deposition: meeting the challenge of thinner films”, Data Storage, pp.35-38, January 1996

- C.S.Bhatia, G.Guthmiller and A.M.Spool, “Alumina Films by sputter deposition with Ar/O2: preparation and characterization”, J.Vac.Sci.Technol. A 7 (3), pp.1298-1302, May/Jun 1989

- R.S.Nowicki, “Properties of RF-sputtered Al2O3 films deposited by planar magnetron”, J.Vac.Sci.Technol. Vol. 14 (1), pp.127-133, Jan/Feb 1977

-V.Gehanno, P.P.Freitas, A.Veloso, J.Ferreira, B.Almeida, J.B.Sousa, A.Kling, J.C.Soares and M.F.da Silva, “Ion Beam deposition of Mn-Ir spin valves”, IEEE Trans. Magn., vol.35, pp.4361-4367 (1999)

-M.Scherer, W.Lehnert, M.Stakic and N.Kling, “Insulating layers for the MR/GMR read elements”, PROXIMITY- Magnetic Storage Industry Sourcebook, p.24, 1998

-Atomic Layer Deposition special report, Solid State Technology, pp.35, January 2003

-M.Tan, S-In Tan and Y.Shen, “Ion beam deposition of Alumina for recording head applications”, IEEE Trans. Magn., vol.31, pp.2694-2696 (1995)