NanoScale Storage Systems Inc. NanoTechnology for Hard Disk Drives Joe Straub 7100 Nanjemoy CT Falls Church VA 22046-3851 Phone: +1-703-241-0882 FAX: +1-703-241-0735 E-mail: joseph.straub@verizon.net Presented at the THIC Meeting at the National Center for Atmospheric Research, 1850 Table Mesa Drive, Boulder CO 80305-5602 August 21-22, 2007 1
Statement of Purpose will design, develop, and fabricate an electron beam based recording head and media as an enabling technology for a hard disk drive platform 2
Outline of Presentation s Product Positioning & Description Competitive Advantage Technology Roadmap Media Development 3
Why Electron Beam Recording Enabling disruptive technology for HDD Leverages many components cost from HDD Better than magnetic disk storage densities (Tb/in 2 ) High Capacity (+1TB) @ very small form factors (1 ) High transfer rate 100+ MB/s Random access & fast seek times Write once & rewrite-able media @ <10 /GB Can reach 1 nm beam diameter molecule-based storage 4
Development Approach NHA Combines two existing technologies Electron beam lithography addresses writing Electron microscope addresses readback Implemented at NanoScale use of a Carbon Nano Tube (CNT) Phase change media Archival & Re-Writeable 5
Build on Hard Disk Drives NS3 will develop a new media for any standard HDD form factor NS3 will develop a new NanoHead Assembly (NHA) to replace the existing GMR head 6
End Product will deliver a transparent solution to HDD manufacturers Head & media Tracking servo technology Read transimpedance amplifier & write driver circuits 7
HDD Block Diagram Read preamplifier Write driver Nano Head Assembly Media Spindle Motor Read / Write Channel Rotary Actuator Combination Servo Control: spindle & VCM Hard Disk Controller CPU System Host I/O (ATA) External program flash Color ID New Tech Components Modified Components HDD standard components 8
The CNT Electron Beam Emitter Picture from a previous work done by the University of Cambridge - UK 9
Schematic Drawing of s Approach ~1 mm dia. Base emitter Nano Head Assembly (NHA) ~1 mm E-beam Deflection Electrode 0.01 mm Media Detection Electrode 10
Read signal Detection Media Disk Read / Write head Read signal is based on secondary electron emission from media Write / Read Actuator Head Enclosure Beam HIGH COLLECTION EFFICIENCY Signal Detector + V + V Media Substrate 11
CNT R/W HEAD R/W Head Spacing ~0.01mm Silicon Wafer CNT Head Array Fab. Tracking via Beam Deflection R/W array increments radially one track (~ 25nm) per disc rotation Individual Head R/W Operation 12
Secondary Electron Detection A graph of MgO SE emission curve versus incident (landing) voltage 13
NHA (IDU) Dimensions 14
3D Drawing of a NHA CNT emitter Collimator lens detector Focusing lens 15
Photograph of an Emitter & a GMR Head GMR Head NS3 Emitter 16
CNT Emitter SEM Picture 17
Performance Requirements Modulation BW: 700 MHz ~ 1 GHz 2 nd generation: 4.5 GHz I-V Characteristics: 1 µa @ 100V 1 st sample: 2 µa @ 50V 18
I-V Plot of Microcathode 19
Competitive Advantage 20
NHA Advantages Parameter NHA Magnetic Head Advantage Working Distance ~ 10 µm ~ 10 nm No head crash Read / Write Head Electron beam column Rectangular head cross section No skew issue versus radius Bit size Limitation E-beam diameter determined by CNT tip radius only Read/write head physical size Easily achieve < 10 nm bit size & maintain same NHA size Head Architecture Bit size is independent of working distance Bit size dependents on fly height Performance beyond 1 Tb/in 2 achievable 21
NHA Advantages Achieving smaller bit sizes is NOT dependent on complicated and expensive head manufacturing technologies like GMR, TMR heads, or thermally assisted recording With the NHA, while maintaining the same manageable physical dimensions (<1 mm 3 ), smaller bit sizes will be realized by controlling the CNT tip radius 22
Technology Roadmap 23
Schematic Representation of a Magnetic Bit vs. NTD Bit Mag. HDD 62 Gb/in 2 (689k bpi x 90k tpi) 76 Gb/in 2 (689k bpi x 110k tpi) 200 Gb/in 2 (1500k bpi x 133k tpi) 314 Gb/in 2 (834k bpi x 376k tpi) 1000 Gb/in 2 (3060k bpi x 330k tpi) 2900 Gb/in 2 track width 282 nm 231 nm 139 nm (2200k bpi x 1000k tpi) 60 nm bit length 37 nm 37 nm 23 nm 27 nm 10 nm 15 nm 10 nm NTD track spacing 68 nm 38 nm (1500k bpi x 677k tpi) 25 nm 24
DISC CAPACITY Nano Disc Data Capacity (TB) vs. Mark Size Mark length, nm 27 19 13.5 9.5 6.8 120 mm 1.0 2.0 4.0 8.0 16.0 Disk Size 3.5 inch 0.55 1.1 2.2 4.4 8.8 25
, Products & Form Factors NS3's Product Capacity Versus Form Factor Enterprise market 10,000 120 mm 3.5" 2.5" 1" CE market 1,000 100 10 Capacity per Platter (GB) 30 25 20 15 10 5 0 1 Bit Length (nm) 26
Data Transfer Rate Leveraging existing low cost HDD channel chips, data transfer rate is similar to existing magnetic disk drives (~1GHz) New preamps can be designed to support higher throughput for the NHA technology 27
Future Technology Roadmap Utilization of the CNT allows for an array fabrication thus enabling parallel recording With parallel recording capability: Data transfer rate increases; 4X, 8X* (i.e. a 1 GHz throughput -> 4, 8 GHz) Access time will be reduced * Space permitting to meet form factor 28
1 inch Drive w/ Parallel NHAs 10 mm 3.5 microns o o o o o o o o CNT Array CNTs 29
Future Technology Roadmap For 1 and smaller size disk drives, a switched array of CNT emitters would cover the full radius. NO Actuator! Once brings about parallel write and read, the technology will become a direct competitor with Solid State memory devices in $/GB 30
Courtesy of University of Cambridge Dr. Ken Teo Designable CNT Arrays 31
Media Development 32
Media Type Archival media as initial product Erasable media as a follow on 33
Media Preliminary Specification Phase Change: Transition temperature 150 ~ 350 deg. C Energy required to raise temperature of a cylinder of 27 nm diameter x 40 nm high from 23 deg to 250 deg C y 0.01 pj (Sb 0.7 Sn 0.15 In 0.15 ) NHA landing energy per pulse at 1.3 GHz (0.8 ns pulse) ~ 0.03 pj 34
High Signal Contrast Technical note on Ge 2 Sb 2 Te 5 - a rewritable phase change material 5 orders of magnitude change in conductivity 35
TEM of Phase Change spots Sb0.7 Sn0.15 In0.15 NS3 (Antimony / Tin / Indium) 36
RISKS & BENEFITS Media Response Unproven Write-Read CNT Head Design Unproven ================================= High Data Rate & High Capacity Single Disk, Media Options NO Head Crashes 37
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