April 16th, 2012
大島 成夫(Jeff Ohshima) Technology Executive
Memory Design and Application Engineering Semiconductor and Storage Products Company
Toshiba Corporation
State-of-the-Art Flash Memory Technology, Looking into the Future
Reorganization as of July. 1
st, 2011
Semiconductor and Storage Products Company
HDD SSD NAND Flash
Near-line CE Client Enterprise
Trad-Enterprise Mobile Industrial
Total Storage Solution by Toshiba
Storage Market Forecast
0 5000 10000 15000 20000 25000 30000 35000
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
800EB
1800EB
35ZB
Flash HDD Opt.
This Gap contain
1. Unused Stream Data 2. Transfer Info. Data 3. Temporary Data
The storage market continues to grow.
Storage capacity will never catch up with the speed of the information explosion.
Info-plosion
Amount of information produced by human activities
出展：TSR社(HDD)、日本記憶メディア工業会(CD/DVD/BD) ベースにTSB 試算。情報生成量/利用可能ストレージ(IDC白書)
Contribution of Flash Memory 1% 2.5% 5%
Capacity [EB]
XX
Server Global
Side
DRAM HDD HDD
HDD HDD HDD
Mobile Phone
NAND
Smart Phone
NAND
HDD
PC
HDD
PC
SSD
Server
DRAM
SSD SSD
HDD HDD
HDD HDD HDD HDD HDD
HDD HDD HDD HDD HDD
Ubiquitous Computing
On Demand Computing SaaS
ASP
Grid
Computing Utility Computing
Cloud Computing
Tape NAND
Current System Cloud Computing Network system
HDD NAND
Client Application
NAND
Global Side
Client Application Car
Car
DSC
Smart TV
HDD SSD
NAND
NAND
DSC Tablet
Replace
NAND
Changes in Data Storage in
‘Cloud Computing Era’
Yokkaichi Factory
Next Gen. 3D Memory
Technology
The Narrowing Road Map to the Future
20 20
Costly Mountains
09年 10年 11年 12年 13年 14年 15年～
Post NAND
NAND 24n
Cross Point 3D
NEMS Memory
Organic Memory Molecular Memory 32n
Extension of FG
Race Track BiCS
Many Candidates
19n
Memory Road Map for Emerging Memory
Working Memory Post-post
NAND
MRAM
What is BiCS technology?
Pillar electrode Plate
electrode
Memory cell Stack
Plug
New 3D stacked memory
High cost effectiveness
Punch
Cell Array Row
Decoder
A break-through concept for 3D memory
BiCS Flash Memory
Vertical poly-Si TFT for cell/Select gate
Charge trap memory with cylinder shape ONO
Shared control gate
Channel Poly Si
Control Gate Block Ox
Tunnel Ox Charge
SiN
Bit Line
Lower SG (GSL) Control Gate
(WL) Upper SG
Source Line (CSL)
Bit Line Upper Select Gate Control Gate Lower
Select Gate Source Line NAND String
BiCS technology applied to NAND flash
P-BiCS Flash
Select Gate Source Line
Non-doped poly-Si Channel
Control Gates
Back Gate Bit Line N+
Diffusion
No Diffusion between gates
P-BiCS has “U” shaped NAND string with back gate to reduce parasitic resistance of bottom portion. There is no diffusion between CGs. Select gate has asymmetric source and drain structure to reduce off current.
Non-Volatile
Random Access memory (Work memory)
Introduction of “STT- MRAM ”
STT-MRAM; Work Memory + Code Storage
10G
Write/Program Cycle Time (s)
Capacity (bits)
1G 100M 10M
1M1E-9 1E-8 1E-7 1E-6 1E-5 1E-4 1E-3 1E-2
NOR
Data Storage 100G
PCM
Code Storage Working Memory
SRAM
BiCS/ReRAM
FG-NAND
HDD
DRAM
MRAM
Target Area of High-density
MRAM
Target Area of FG-NAND/
Post-NAND Scaling
MRAM > PCM ⇒ ･Program time、･P/E Endurance
STT-MRAM Target Field
DRAM based Applications
Server
PC
Handset
Tablet DSC
DVC etc…
Why STT-MRAM ?
DRAM Scaling Down continously ??
Difficulty ??
At DRAM Cell Capacitor beyond 20nm
More Refresh
▶ More Power
More Refresh
▶ Poor Performance
STT-MRAM could cover beyond 20nm working RAM field.
STT (Spin-Transfer Torque) MRAM Non-volatile & Resistive Cell
What is STT-MRAM?
- Electron spin to store data
- Magnetic storage elements (MTJ: Magnetic Tunnel Junction)
Parallel Spin State State “0”
(Low Resistance)
Anti-Parallel Spin State State “1”
(High Resistance)
Ferromagnetic Reference Layer
Ferromagnetic Storage Layer Tunnel Barrier
Summary
• FG NAND
– Continuous scaling is on going for 2X/1Xnm FG- NAND and as far as possible
• Post NAND
– BiCS and ReRAM are most promising candidate.
And now test chip learning is on going
• STT-MRAM
– Spin Transfer Torque MRAM is the promising
memory, Non-volatile, high speed random access, unlimited cycling
