Perspective on Probe Storage

Agrate, 11th June ‘09

Bruno Murari

Roadmap

What we have done in ST on Probe Storage (1999-2007)

• ARS (Atomic Resolution Storage) Program with HP (1999-2003)– HP (Carly Fiorina) stopped the ARS project in 2003 for cost and

time to market issues

• Millipede1 Development Program with IBM (Sept 2003 – March 2005)– ST top management decision to close collaboration with IBM

• Nokia input for high density memory device: September 2005

• Resart ST-IBM Probe Storage/Millipede2 collaboration under Nokia pressure : December 2005

• Seagate-ST Probe Storage Co-development agreement: November 2006

• IBM-Seagate-STM meeting to decide the future : April 2007– Seagate, followed by ST, stopped the program in May 2007 related to

very aggressive roadmaps for NAND Flash technology/cost and revised market risk analysis.

HP Atomic Resolution Storage (ARS)

How to realize the ARS micromover

Feedthrough Spring

Rotor electrodes Stator electrodes

Rotor Stator

Bonded poly

Bonded Pd

Rotor electrodes Stator electrodes

100 um

Flat Emitter Concept

e- trajectoriesle

ns

anod

e

flat e

mitt

er

Electrostatic Scanning Motors

PlatformPlatform

FlexuresFlexures

IBM Millipede1 : sample of single Cantilever on SOI wafer

Single Lever Thermomechanical R/W Test BenchST first lot result : areal density 511Gbit/in2 (2004)

• 50nm pitch

• 35 nm pitch

IBM Single Lever Test Bench

Millipede1 : Micro-mover prototype

400 µm

Spring dimension: 10 umAspect ratio 1:40

Spring width : 10 umAspect ratio 40:1

6” Micromover prototype

flat media

Tip apex: 5±1.5 nm radiusTip angle: 25 degrees

Tip apex: 4.5±1.5 nm radiusTip angle: 41 degrees

Millipede2 : Density Scaling

Experimental results in excellent quantitative agreement with scaling predictions from 0.8 to 4 Tb/in^2 irrespective of tip cone angle

standard media

2Tb/in^2 8.5dbSDR

flat media

2Tb/in^2 9.3dbSDR

3Tb/in^2 10.2dbSDR

4Tb/in^2 6.3dbSDR

Tip wear (read)

Dry air + force modulation Dry air Ambient Humidity

Sliding Distance ~ 750m

Sliding Distance ~ 13mSliding Distance ~ 700malmost no wear

0 100 200 300 400 500 600 7000

2

4

6

8

10

Fadh

(nN

)

sliding distance (m)

STC12 STC20

Wear rate: STC20: 0.25nm3/m

STC12: 20 nm3/m

Radius: STC20: ~16nm

STC12: ~4.5nm

STC20 STC12Experimental Conditions:Contact sliding in Dry Air, 1.5mm/sHot NMP washed PEAK 42BRelative Humidity ~ 0%Sliding distance ~ 750m (7.5E10 read events)

Modulation of the "normal force" that acts between the surfaces in contact (tip and medium) at frequencies at or higher than theresonance frequencies of the two bodies, results in variation ofthe interaction energy and thereby reduces friction dramatically.

w/o modulation force

w/ modulation force

Towards Super-lubricity with Force-modulation

GST

Tip

Substrate

Molten GST

Chalcogenide Phase Change Material:Chalcogenide Phase Change Material:20 nm 20 nm pitch (1.6Tb/in2) electro(1.6Tb/in2) electro--thermal simulationthermal simulation

Temperature distributionTemperature distribution

Magnetic Ferroelectric

Magnetic Field detector

Electric Field detector

Magnetic Media vs Ferroelectric Media

H

M/m3

V

Q/m3

12- 50 MJ/m3

2- 5 MJ/m3

Perovskite Structure Tetragonal

Perovskite Structure Tetragonal

Si Substrate

SrRuO3 (SRO)SrTiO3 (STO)

Lube

PZT

Ferroelectric Media

• Deposition of media by MOCVD • Main issues :

– Media protection– lubrification technologies

Seagate architecture : ST proposal for Ferroelectric Cantilever

System & Packaging Concept

CMOS

Rotor+Stator8x8 mm

Probe Storage vs N FLASH Price $ / GByte

2009 20112010 20132012 2014 20152007

0.5

1

2

4$

0.25

0.122008

N_Flash Tech. Node : 45 nm 32 nm 22 nm 15 nm

Scenario 1

Scenario 2

Probe

Areal Density : 2.5Tb/sqinchCapacity on MMC Size: 64 GB

5Tb/sqinch128 GB

10Tb/sqinch256 GB

What we have learnt

• Through Silicon Vias • Deep silicon etch with high aspect ratio• Temporary bonding• Wafer to wafer bonding• Hermetic sealing on cavity• Floating metallization• Non conformal lithography• 3D integration• System design, including package

LAB on CHIP from Printer Cartridge ?A real example of Lateral thinking…

Buried Channels for disposable Print Head Chip in Inkjet

Cartridges

Buried Channels for miniaturized PCRin disposable Lab on Chip

ST MEMS Growth and 8” Fab

0

20

40

60

80

100

120

140

160

180

200

220

240

2005 2006 2007 20080.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

8.0%

9.0%

10.0%

MEMS Revenues MEMS Market Share

> 10x

> 3x

> 2x96M

209M

30M8” Fab in Milan

ST leads the “MEMS Consumerization Wave”

Next steps …

• The science has a discovery : mechanical position movement could be controlled with a 2A precision.We don’t know how to exploit it: the only idea up to now is to use for memory storage

• The “super lube” technology have to be exploited for different field applications.The tribology science has shown recently a strong improvement in C-drug reduction using ultrasonic vibration for mechanical part and fluidic system. How to use it ?

• The archive market is requiring a life improvement in memory storage up to more that 200 years .How to solve it ?

• The deep knowledge on nano-structured materials has an increasing impact on different devices.