Potential Flexible Electronics Applications Using CNF as Substrate: Opportunities and Challenges

Zhenqiang (Jack) MaZhenqiang (Jack) MaLynn H. Matthias Professor in Engineering and

Vilas Distinguished Achievement Professor@ i dmazq@engr.wisc.edu

University of Wisconsin-MadisonDepartment of Electrical and Computer Engineering

In collaboration with Dr. Zhiyong Cai and Dr. Ronald Sabo at Forest Product Lab,

P f Sh i (S h) G UW M di d P f W idd ZhProf. Shaoqing (Sarah) Gong at UW-Madison and Prof. Weiddong Zhou at

University of Texas-Arlington

Electronics research funded by AFOSR Dr Gernot Pomrenke

NNI/FS Workshop: Cellulose Nanomaterials – A Path Towards Commercialization

Electronics research funded by AFOSR, Dr. Gernot Pomrenke

May 20-21, 20141

OutlineOutline

R l f l t i i US d ld• Role of electronics in US and world economy (GDP).

• Electronic garbage.• Electronics manufacturing and what is needed

for an electronic chip.• “Chip” can be made on foreign substrates, p g ,

including on disposable CNF substrates, using single crystal nanomembranes.g y

• Challenges

2

Electronics contribution to world and US economy

http://india-reports.in/shop/power-point-slide-on-telecom-electronics-hardware-production-as-share-of-gdp-for-select-countries-including-india/ 3

http://india-reports.in/shop/power-point-slide-on-telecom-electronics-hardware-production-as-share-of-gdp-for-select-countries-including-india/

4

Electronics help on• GDP growthGDP growth• Job opportunity• Life quality• …

<Financial Times, http://ftalphaville.ft.com/blog/2012/04/04/947201/the-return-of-, p // p / g/ / / / /the-us-manufacturer/>

5

<Financial Times, http://ftalphaville.ft.com/blog/2012/04/04/947201/the-return-of-the-us-manufacturer/>

6

Electronic garbage

http://www.scientificamerican.com/blog/post.cfm?id=major-us-recycler-vows-to-stop-ship-2008-09-23http://urbanmedialabwaste.files.wordpress.com/2011/04/e-

waste.jpg

426 000 Discarded Cellphones/day in USSeptember 2007, IEEE Spectrum

http://urbanmedialabwaste.wordpress.com/author/cindypound/

7

Histogram of electronic products collected for recycling or disposed from 2000 to 2009

http://www.electronicstakeback.com/2011/01/26/epas-new-figures-show-most-e-waste-still-getting-trashed/

In 2009, as in previous years, the vast majority (82.3%) of e-waste discarded in the U.S. is still ending up in our landfills andincinerators, with only 17.7 percent going to recyclers

8

Table of electronic products collected for recycling or disposed in2010

Facts and Figures on E-Waste and Recycling9

Quantity of electronic products collected for recycling or disposed, by type and by year.

U.S. Environmental Protection Agency Office of Resource Conservation and Recovery Electronics Waste Management in the United States Through 2009

http://www.epa.gov/osw/conserve/materials/ecycling/docs/fullbaselinereport2011.pdf10

Electronics product manufacturing cycle

11

Electronic chip manufacturing (as an example)

Cross section of a fabricated chipCross section of a fabricated chip

Device layer thickness <0.3 um

Expensive resources, such as precious and rare earth metals are used.12

Electronic chip manufacturing

525 um for 4 inch wafer

675 um for 6 inch wafer

775 um for 12 inch wafer

725 um for 8 inch wafer

775 um for 12 inch wafer

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Various examples of

“Chips” on foreign substrates(Flexible electronics research at UW-Madison)

Typical process for releasing and transferring single-crystal semiconductors

Various examples of transferred single crystal

semiconductors

Sacrificial layer Finish transferring Si

Stacked Si

layer

StartFinish transferring Si

P tt d d t

New host substrate

Place nanomembranePattern and undercut

Stamp

Place nanomembrane

GaAs InP

Finish undercutting Pick up nanomembrane

14K. Zhang, et al, J. Phys. D: Appl. Phys. 45 (2012) 143001.

(Flexible) “Chips” on foreign substrates

World’s first radio-frequency (RF) flexible

thin-film transistorthin film transistor (TFT)

Yuan and Ma, APL 89, 212105, (2006)., ( )

H C Y Z M l J A l PhH.-C. Yuan, Z. Ma, et al., J. Appl. Phys.102, 034501 (2007).

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Very fast flexible “Chips” on foreign substrates

Strips

PET

(a)

(b) (b’)

Light

“Local”mask Local

alignment markers

Finished circuits

(c) (d)

Light

Flexible substrate

PET PET(e) (f)

Light

1 cm 1 cmPDMS PET

30

40W = 40 um, L = 1 umV = 2 V V = 4 V

10

20

30dB

), H

21(d

B)

Gmax

Vgs = 2 V, Vds = 4 V

fmax= 12 GHz

-10

0

10

108 109 1010

Gm

ax ( H21

fT=3.8GHz

16

108 109 1010Frequency (GHz)

L. Sun, et al, Small 6(22), 2010.Higher frequency/speed is readily feasible.

Radio frequency passives on foreign substrates

17L. Sun, et al., APL (96) 013509, (2010)

Toward low-cost and disposable electronics“transistors” on CNF s bstrates--“transistors” on CNF substrates

(Flexible electronics research between UW-Madison and FPL)Strips N b S b t tStrips Nanomembrane Substrate

Transferred SiNM on

Au

Transferred SiNM oncellulose nanofiber

substrate

SiNM

18Au

Working flexible transistors demonstrated on CNF films

1 10-6

Vg=0VVg=1V 7

10-6

1.4 10-7Vd=0.1V

6 10-7

8 10-7Vg=1VVg=2VVg=3VVg=4VVg=5V

nt (A

)

10-9

10-8

10-7

8 10-8

1 10-7

1.2 10-7

nt (A

)

Transcon

ID

gm

d

4 10-7

Dra

in C

urre

10-11

10-10

10

4 10-8

6 10-8

8 10

Dra

in C

urre

ductance (s

I

0

2 10-7

D

10-13

10-12

10

0

2 10-8D s)IG

0 1 2 3 4 5 6 7

Drain Voltage (V)

10-4 -2 0 2 4

Gate Voltage (V)

R Sabo et al Proceedings of 2012 TAPPI International Conference on

19

R. Sabo, et al., Proceedings of 2012 TAPPI International Conference on Nanotechnology for Renewable Materials, Montreal, Canada, June 4-7, 2012.

ChallengesChallenges

i f C b i• Requirements for CNF substrate properties – Surface smoothness– Mechanical strength– RF properties– Dielectric properties– Thermal properties– Processing and metrology compatibility with

semiconductor infrastructure– Reliability– Moisture barrier/Encapsulation

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