Nanoscale Electrochemical Switches

Dr. James G. Kushmerick

OFF ON

Nanoscale Electrochemical Switches

OFF ON

1. OFF state – molecular tunnel junction

2. Vthreshold reached. Ag+ filament bridges gap. Switches ON.

3. Remains in ON state until polarity switched.

4. At 0 V, device is returned to OFF state.

Device can be rapidly cycled between ON and OFF

Greater than 1 million switch cycles achieved

Fastest monolayer switch to date = 13 kHz

On-Off Ratio > 105

Device area ~ 25 nm2

~ 2 nm

Detail of Switch Mechanism

Why would anyone be interested in a nanoscale

switch?

CMOS Scaling

1970 1980 1990 2000 2010 2020

Min

imu

m F

eatu

re S

ize

(m

)

0.01

0.1

1.0

10

65 nm node

(2005)…drives Si technology towards fundamental limits

Courtesy INTEL

Courtesy of IntelRock’s Law: the cost of a semiconductor chip fabrication plant doubles every four years

Nanoscale Crossbar Fabrication

Science 300 (2003) 112-115

State of the Art Filament Switches

Advantages• Ease of fabrication• Huge On-Off Ratio (>105)• High success rate for device fabrication (>90%)• Small Device Area (~25 nm2)

Challenges/Opportunities• Slow Switch Speed (~10 kHz) defines possible

applications (e.g. memory arrays and FPGA)• Not easily integrated into CMOS fab-line, but no fab-line

needed

Technology Applications

• Nanoscale Electrical Devices

– Memory Arrays

– Field-Programmable Gate Arrays

Commercial Applications

• Memory and logic for cell phone and other portable electronic devices

Future Work

• Optimization of switch characteristics– Increase switch speed– Increase # of cycles till failure

• Fabricate nanoscale memory devices

Collaboration Opportunities

• Future work would best be done in collaboration between NIST and an interested industrial partner.

• Intellectual Property:

“Self-Assembled Monolayer Based Silver Switches ”

Provisional Patent Application filed 9/10/2007

Serial # 11/852,811

Contact Information

• For further information contact:– James G. Kushmerick

100 Bureau Drive Stop 8372Gaithersburg, MD 20899-8372

Tel: (301) 975-5697email: james.kushmerick@nist.gov