don’t forget the memory… dean klein, vp memory system development micron technology, inc

Don’t Forget the Memory…Dean Klein, VP Memory

System Development

Micron Technology, Inc.

©2007 Micron Technology, Inc. All rights reserved.

2

Memory is Everywhere


3

One size DOES NOT fit all…


4

Question:

• How many different memories does your

computer use?


5

The Evolving Memory Hierarchy

Level 1 Cache

Level 2 Cache

Main Memory

Disk Boot ROM


6

Question:

• How many different memories does your cell

phone use?


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The Cell Phone Memory Hierarchy

Instruction Cache

Data Cache

Boot ROM

uSD Card NAND

NAND Flash

PSRAM or LPDRAM

MCP


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What is the Ideal Memory?

• Fast – to keep pace with processors

• Reliable – not susceptible to corruption

• Low cost – pennies per mm2

• Small – helps with low cost, but also for new

platforms

• Embeddable – ability to be integrated with

logic

• Low power – for dense systems and un-

tethered systems

• Non-volatile – no power required to retain

data


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Industry Reported Cell Sizes

Cell Size (u2) Tech Node (nm) Cell size (F2) Endurance

IBM/Infineon MRAM

0.74 130 44 Excellent

Freescale 6T-SRAM


Intel 45nm 6T-SRAM


Freescale TFS: Nanocrystaline

0.13 90 16 Unknown

Freescale eDRAM


Samsung 512Mbit PRAM Device

0.050 95 5.5 1E7??

Micron 40-series DRAM


Micron 60-series NAND

0.0046 34 4 Good


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Benefit of Shrinking

• The ability to fit more bits on a wafer,

thereby reducing the cost of those

bits.

• The ability to add features to a

product, thereby increasing

performance.

• The ability to lower the power of the

device.


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DRAM Operation


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NAND Flash Memory

• The “ideal” memory?

• Non-volatile

• Small cells – Under 6F2

• Low cost process

• Scaleable?

• Wear issues?

• Slow writes

• Ideal for some applications


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NAND Operation

• Control Gate traps

electrons injected

by Fowler-Nordheim

tunneling.

• Voltages of up to

20V exist during cell

programming.p-sub

N-well

p-wellN+ N+

Source Drain

ControlGate


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NAND Programming Operation


electrons injected

by Fowler-Nordheim

tunneling.



programming.p-sub

N-well

p-wellN+ N+

Source

OpenDrain

0V

ControlGate

20V

0V

0V

0V

Cell is programmed to “0”


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NAND Storage Operation


electrons injected

by Fowler-Nordheim

tunneling.



programming.p-sub

N-well

p-wellN+ N+

Source Drain

ControlGate

Cell retains its “0” state


16

NAND Read Operation


electrons injected

by Fowler-Nordheim

tunneling.



programming.p-sub

N-well

p-wellN+ N+

Source

Reads 0V

Drain

4.5V

ControlGate

0V

0V

0V

0V

Cell read in “0” state


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NAND Read Operation


electrons injected

by Fowler-Nordheim

tunneling.



programming.p-sub

N-well

p-wellN+ N+

Source

Reads >0VDrain

4.5V

ControlGate

0V

0V

0V

0V

Cell read in “1” state


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Questions:

• In 1982, as the personal computer became

successful, how many memory bits were

there in a standard memory chip?

• In 2010 how many memory bits are in a

leading edge standard NAND Flash memory

chip?


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Questions:

1. How fast is the speed of light?

2. How far can light travel in the single “tick”

of a 3GHz processor clock?


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Question:

• How many ticks of the 3GHz processor clock

does it take to access the average piece of

data on a 7200RPM hard drive?


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Why SSD’s?

• Performance


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SSDs in Computing

1 L1 Cache 1,800

2.5 L2 Cache 1,400

1,200 DRAM 10

RelativeLatency

RelativeCost/bit

CPU

NAND Flash Closes the Latency Gap

Cost/bit Data as of November 2007

25,000,000 HDD 1NAND 25,000 SSD 3


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Why SSD’s?

• Performance

• Power


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Notebooks: SSD’s Can Improve Battery Life

Power consumption decreases when solid state

drives are used in today’s notebook computers.

HDD SSD

Power


25

SSD: Power and Performance

SSDs do more with less

power


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Why SSD’s?

• Performance

• Power

• Reliability


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HDD & SSD in the Enterprise Server Market


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Why SSD’s?

• Performance

• Power

• Reliability

• New Form Factors


Innovative Platforms

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Memory Research Areas

• DRAM: New materials, High-K gates, Low-K dielectrics New structures: 3D transistors, lattices New features: Ultra-high bandwidth, lower power

• New types: MRAM FeRAM Polymer Programmable conductor Phase Change memory ‘Nano’ (?) Micromechanical/nano (Millipede)


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Top 10 Reasons You Want to Be an Engineer

1. For the great memories!

2. It rationalizes why you always took things apart as a kid

3. You always were fascinated by trains

4. It sure beats flippin’ burgers!

5. You love calculus, differential equations, numerical analysis…

6. At least your computer listens to you

7. You would have been a doctor or a lawyer, but where’s the challenge?

8. You believe anything is possible

9. You’re going to get rich off that cold fusion project you have going in your bathtub

10.It’s logical


Final Advice:

Be a “T” person!

33

Questions?

don’t forget the memory… dean klein, vp memory system development micron technology, inc

Documents

cmos technology

technology thatwe

fit all2007 micron technology

storage gaps

large markets

dram business

nand flash memory business

evolving memory hierarchylevel