Greg Yeric
© 2017
Why did the semiconductor industry get so excited about graphene?
2
Greg Yeric
© 2017
The problem with planar MOSFETs
3
Gate
Source Drain
Substrate
One-dimensional field leakage
Greg Yeric
© 2017
0.01
0.10
1.00
10.00
1970 1980 1990 2000 2010 2020
Feat
ure
Siz
e, u
m
Year of Production
Technology Node, um
Physical Gate Length, um
Strain Era
3
2
1.5
0.81.0
0.50.35
0.250.18
0.090.13
0.0650.045
0.032
0.020
0.014
Gate length scaling hampered by leakage,
Reduces drive current scaling,
Make that up with channel strain to
increase mobility
Greg Yeric
© 2017
CMOS strain era
1
10
100
1000
10000
100000
1980 1985 1990 1995 2000 2005 2010 2015 2020
Conventional NMOS
Conventional PMOS
mobili
ty
Greg Yeric
© 2017
MOSFET Stress, if at macro scale
PMOS Stress
NMOS Stress
1 square inch chip:
Greg Yeric
© 2017
0.01
0.10
1.00
10.00
1970 1980 1990 2000 2010 2020
Feat
ure
Siz
e, u
m
Year of Production
Technology Node, um
Physical Gate Length, um
~16/14nm: We needed better electrostatics
FinFET:
Scale gate lengths,
Reduce leakage
3
2
1.5
0.81.0
0.50.35
0.250.18
0.090.13
0.0650.045
0.032
0.020
0.014
FinFET gate (blue) can exert
field from both left and right
Greg Yeric
© 2017
Gate All-Around Horizontal Nanowire
8
5nm 3nm
???
Greg Yeric
© 2017
Materials innovation: Graphene
Andre Geim Konstantin Novoselov
+ = 2010
Nobel Prize
9
2004:
Greg Yeric
© 2017
Graphene FET
Best possible field confinement
Greg Yeric
© 2017
Device Mobility Comparison
1
10
100
1000
10000
100000
1980 1985 1990 1995 2000 2005 2010 2015 2020
Conventional NMOS
Conventional PMOS
graphene N and P
mobili
ty
Greg Yeric
© 2017
Transistor scaling’s dirty secret: Parasitics
12
HS Wong, et al., SISPAD 2009
Greg Yeric
© 2017
Graphene FET
100x mobility
Best possible field confinement
Low aspect ratio = low parasitic cap
BUT: no band gap!
Greg Yeric
© 2017
No band gap: Not good for VLSI, maybe OK for AMS
http://beforeitsnews.com/science-and-technology/2011/04/ibm-researchers-
develop-a-155-ghz-graphene-transistor-using-a-diamond-like-carbon-
substrate-545003.html
http://www.popularmechanics.com/how-to/blog/ibm-builds-a-
graphene-circuit-16451798
Feb 2014:
IBM sent a text message
using graphene transistors
Greg Yeric
© 2017
Graphene bandgap?
Edge treatments
Doping
Hunt, et al. Science, June 2013, v340, n6139 Liu, et al., Nature Nanotechnology 8,
2013, pp 119-124
Yang, et al., GLSVLSI 2010,
pp 263-268
No band gap!
Greg Yeric
© 2017
Graphene timeline: 2004-
Andre Geim Konstantin Novoselov
16
+ = 2010
Nobel Prize2004:
Greg Yeric
© 2017
Representative “new material” timeline:
1984 GMR Effect discovered
1996 Spin Torque Transfer is proposed]
1996 Motorola begins MRAM research
1998 First Motorola MTJ
1999 Motorola develops 256Kb MRAM Test Chip
2002 Toggle patent granted to Motorola
2004 Motorola separates semiconductor business into Freescale Semiconductor
2006 Industry first MRAM (4Mb) product commercially available
2008 Freescale Semiconductor spins out MRAM business as Everspin Technologies
2010 Everspin qualifies industry first embedded MRAM
2010 Everspin releases 16Mb density
2012 Everspin produces 64Mb ST-MRAM on a 90 nm process
2016 Everspin announces 256Mb ST-MRAM to customers
17
~30 y
ear
s dis
cove
ry t
o p
roduct
Greg Yeric
© 2017
Graphene…
…has opened the Pandora’s box
of 2D materials
Hunt, et al. Science, June 2013, v340, n6139 Liu, et al., Nature Nanotechnology 8,
2013, pp 119-124
Yang, et al., GLSVLSI 2010,
pp 263-268
No band gap!
Greg Yeric
© 2017
Graphene for future VLSI
Greg Yeric
Fellow
ARM Research
and other 2-dimensional materials^
Greg Yeric
© 2017
MoS2 FET
Molybdenum Disulfide:
Actual band gap (1.9V)
These have been made and work
My favorite, because it’s a “MoS2FET”
Greg Yeric
© 2017
Molybdenum Disulfide (MoS2) in the wild:
21
Transistors: How far can they go?
22
Oct 2016
Greg Yeric
© 2017
1nm gate length transistor: looks like a transistor
23
Greg Yeric
© 2017
Technology node and transistor gate length
24
0.001
0.010
0.100
1.000
10.000
1970 1980 1990 2000 2010 2020 2030
Feat
ure
Siz
e, u
m
Year of Production
Technology Node, um
Physical Gate Length, um
Greg Yeric
© 2017
MoS2 microprocessor
25
http://spectrum.ieee.org/nanoclast/semiconductors/devices/the-most-complex-2d-microchip-yethttp://www.nature.com/articles/ncomms14948
Greg Yeric
© 2017
Example of the materials revolution: 2D materials
These are just the raw materials. Then you can dope, give them edge treatments, etc.
Z. Geng et al.,
“2D Electronics - Opportunities and Limitations”
ESSDERC 2016
26
*
Greg Yeric
© 2017
MoS2
Molybdenum, a metal
Sulfur, a chalcogen
oxygen, sulfur, selenium, and tellurium
chalco: “copper”
Berzelianite:
copper selenide
Covellite:
Copper Sulfide
Cupric Oxide
Weissite:
Copper Telluride
gen: born from:
Greg Yeric
© 2017
MoS2
Together, a chalcogenide
Greg Yeric
© 2017
MoS2
Specifically, a dichalcogenide
Greg Yeric
© 2017
MoS2
Most of the interesting metals for semiconductors are “transition metals”,
“….partially filled d sub-shell….”
Greg Yeric
© 2017
MoS2
So you have a TMD: Transition Metal Dichalcogenide
(lazy people say MX2)
X 2
Greg Yeric
© 2017
What can we do with more than one 2D layer?
32
2012 Device Research Conference
Greg Yeric
© 2017
What if you can’t make a good transistor?
33
Greg Yeric
© 2017
0 20 40 60 80 1000
5
10
15
20
25
30
Line width [nm]
[
-cm
]
Graphene Nanoscale Resistance Model
Primary advantages: reduced “size effect” impact and resistance
Graphene (Stanford 2D Model):
Rrough,edge = 2 nm
λMFP = 30 nm
ρlow = 1.5×10-6 Ω-cm [1]
ρmid = 4×10-6 Ω-cm [1]
Cu (FS-MS Model):
Rcu = 0.72
ρcu = 1.68 × 10-6 Ω-cm
ARcu = 2
pcu = 0.8
λMFP,cu = 39 nm
ρmid Graphene (MoO3)
ρlow Graphene (FeCl3)
Cu (Foundry)
[1] D. Kondo, N. Yokoyama, et al., “Sub-10-nm-wide Intercalated Multi-Layer Graphene Interconnects with Low
Resistivity,” 2014 IEEE International Interconnect Technology Conference/Materials for Advanced Metallization (IITC/MAM)
𝑅 =𝝆𝑙
𝐴
Greg Yeric
© 2017
While everyone is talking about 2D transistors…
35
16/14nm Cu wire
~32nm wide
AIST
IITC 2014
Greg Yeric
© 2017
What if you can’t make a good transistor?
Thermal conductivity 2x copper
Breakdown current 10x copper
Young’s modulus 8x copper
Electromigration JMAX 1000x copper
36
Greg Yeric
© 2017
But wait! There’s More (than Moore)
37
https://www.nwo.nl/en/research-and-
results/research-projects/i/87/11987.html
Greg Yeric
© 2017
But wait! There’s More (than Moore)
38
https://m.phys.org/news/2017-05-
valleytronics-advancement-law.html
Greg Yeric
© 2017
But wait! There’s More (than Moore)
39
Greg Yeric
© 2017
2D materials manufacturing: rapid progress
40
Greg Yeric
© 2017
2D materials manufacturing: rapid progress
41
https://futurism.com/scientists-have-turned-cooking-oil-into-a-material-200-times-stronger-than-steel/
Greg Yeric
© 2017
42
https://futurism.com/we-may-finally-have-a-way-of-mass-producing-graphene/
Greg Yeric
© 2017
Graphene is not selfish
43
https://m.phys.org/news/2017-
04-graphene-machine-cheap-
semiconductor-wafers.html
Greg Yeric
© 2017
Graphene is not selfish
44
http://spectrum.ieee.org/nanoclast/semicond
uctors/materials/graphene-makes-infinite-
copies-of-exotic-semiconductor-wafers
Greg Yeric
© 2017
Why VLSI might not matter to graphene’s success
45
Greg Yeric
© 2017
Other 2D material uses
46
https://m.phys.org/news/2017-05-graphane-efficient-
water-free-hydrogen-fuel.html
Greg Yeric
© 2017
Other 2D material uses
47
Greg Yeric
© 2017
Other 2D material uses
48
http://spectrum.ieee.org/nanoclast/semiconduct
ors/materials/twodimensional-materials-go-
ferromagnetic-creating-a-new-scientific-field
Greg Yeric
© 2017
Other 2D material uses
49
Greg Yeric
© 2017
Other 2D material uses
50
http://pubs.rsc.org/-/content/articlelanding/2017/ta/c7ta01857f#!divAbstract
Greg Yeric
© 2017
Other 2D material uses
51
http://www.materialstoday.com/computation-theory/news/topological-superconductivity-in-2d-materials/
Greg Yeric
© 2017
Other 2D material uses
52
Greg Yeric
© 2017
Other 2D material uses
53
Greg Yeric
© 2017
Other 2D material uses
54
https://link.springer.com/article/10.1007/s10854-017-6896-4
Greg Yeric
© 2017
Other 2D material uses
55
https://m.phys.org/news/2017-04-graphene-coating-
deformed.html
Greg Yeric
© 2017
Other 2D material uses
56
https://www.dogonews.com/2017/4/27/gra
phene-sieve-may-help-solve-the-worlds-
water-woes
Greg Yeric
© 2017
Why VLSI might not matter to graphene’s success
Age of articles cited in this section, in days:
57
8
28
97
101
20
15
5
5
13
44
142
14
10
27
29
31
12
Greg Yeric
© 2017
Summary
Graphene: Will it revolutionize VLSI? Probably not.
Graphene did open up a Pandora’s Box to a new class of materials (and physics).
There is a vast amount of research into other materials, including x-genes and TMDs.
We may see improved CMOS devices from this research, but there may also be new transistor
paradigms that could replace CMOS: Spin, valley.
Graphene and 2D materials could improve signal wiring, thermal problems, and even I/O (photonics,
plasmonics)
Graphene also recently shown to enable low-cost layer transfer
Beyond VLSI, graphene and other 2D materials will almost certainly change the world.
There is simply too much diverse research showing promise to not assume this.
58
Text 54pt sentence case fin
59
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