Transcript Title

Thin-Film Inorganic HighPerformance Devices via Additive
Processing
4/5/2005
Inorganic Devices via Additive Processing
Thin-Film Inorganic High-Performance
Devices via Additive Processing
Semiannual Review, April 2005
Chemistry – Jeremy Anderson, Stephen Meyers,
Jason Stowers, Douglas Keszler
Electrical Engineering – David Hong, John Olson,
Hai Chiang, John F. Wager
Chemical Engineering – Yu-jen Chang, Alex
Chang
2
Inorganic Devices via Additive Processing
Goals:
• Demonstrate low-temperature fabrication (T < 100oC)
• Achieve high performance in transistor mobility
(μFE  50 cm2/Vs)
• Complementary n- and p-type behavior in solution
processed semiconductors
3
Inorganic Devices via Additive Processing
Process:
• Materials identification and invention
• Literature precedents, physical and chemical
models
• Physical vapor deposition of thin films
• Chemical process development
• Single-source precursors
• Nanolaminates
• Printing
• Device characterization and development
• Transistors and capacitors
4
Inorganic Devices via Additive Processing
Results:
• Enhanced performance in HafSOx dielectric
• New low K phosphate dielectric
• New single-source precursor for near roomtemperature deposition of ZnO
• Nanolaminates for toolbox approach to
multicomponent materials and control of function
• Use of nonaqueous solutions for ink-jet printing
• Solution processed transistor (dielectric + channel)
• Materials/Process Studies: Physical vapor
deposition of new oxide transistors and p-type
5
oxides
Solution Phase Deposition of
Inorganic Thin Films
6
Strategies for Solution Based
Thin Films
1. Deposit film as solid phase constituents
- no extra anneal
2. Add organic thickener
- burnoff required
3. Add additional ions
- incorporate into film, rinse, or burnoff
4. Polymerize material on surface
- vaporize solvent
7
Importance of Liquid/Solid
Thin Film Conversion
Parameters:
• Temperature
• Ramp rate
• Ambient
• Film thickness
• Composition
400ºC
600ºC
8
Higher Permittivity Dielectric
by Layering Technique
medium k (amorphous)
example: Hafsox
medium k (amorphous)
high k (crystalline)
medium k (amorphous)
high k (crystalline)
high k (crystalline)
example: TiO2, Ln2O3
medium k (amorphous)
high k (crystalline)
medium k (amorphous)
substrate
9
Buffer Films for Control
of MOSFET
conduct
conduct
channel
dielectric
dielectric buffer
conduct
conduct
channel
channel buffer
dielectric
conductor
conductor
substrate
substrate
Solution-Based Deposition
Jeremy Anderson
Stephen Meyers
Jon Olson
Hydrated oxides
-no layer mixing-
oxide #1
oxide #2
anneal
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Hydrated oxides
-complete layer mixing-
oxide #1
oxide #2
anneal
ternary oxide
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Demonstration of smooth reproducible thin
layers
Hafsox
Zircsox
substrate
Film thickness demonstrated at 5 nm.
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X-ray reflectivity for Hafsox/Zircsox multilayer
film
8
log (cps)
6
4
2
0
0
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2
4
6
2 theta
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10
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Conversion liquid film to solid film
L
M
polymerization
H
OH
L
H
M
M
O
L
M
M
M
M
O M
M
O
L
O
M
M
O
M
O
M
O
M
M
O
M
O
M
O
O M
O
M
O
M
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combustion
L
L
O
O
H
M
M
M
L
L
O
M
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Rapid Low Temperature Reaction
•
Dense film formation requires extended bond
formation
•
Polymerization process should have low activation
energy
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Rapid Low Temperature Reaction: Hafsox/La
Reaction Hafsox
325º C
HfOCl2 + x H2SO4 + (1-x) H2O
HfO2-x(SO4)x + 2 HCl
Reaction Hafsox/La
325º C
HfOCl2 + x La2(SO4)3 + H2O
HfLa2xO2(SO4)3x + 2HCl
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Rapid Low Temperature Reaction: Tin oxide
phosphate (TOP)
600º C
SnCl4 + H2O2 + 2H2O
600ºC
SnO2 + O2 + 4HCl
No transistor behavior
500º C 500ºC
SnCl4 + x H3PO4 + (2-3x/2) H2O
SnO1.7(PO4)0.2 + 4HCl
Transistor behavior
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Rapid Low Temperature Reaction: ZnO
Limitations of Past Approaches
High processing temperatures, poor performance and
non-ideal behavior caused by:
• Residual spectator ions (Halides, Nitrates, Etc.)
• Combustion products (Organics)
• Grain boundaries
• Film defects due to material loss
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Rapid Low Temperature Reaction: ZnO
Precursor:
ZnCl2(aq) + 2NH3(aq) +2H2O → Zn(OH)2(s) + 2NH4Cl(aq)
Centrifuge and Rinse
Zn(OH)2(s) + xNH3(aq) ↔ Zn(OH)2(NH3)x(aq)
Conversion
Zn(OH)2(NH3)x(aq) → ZnO(s) + xNH3(g) + H2O(g)
300º C
pH
-1
1
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Zn+ (aq)
5
7
9
11
Zn(OH)2(s)
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-2
Zn(OH)4 (aq)
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Rapid Low Temperature Reaction: ZnO
Results
•Polycrystalline ZnO films
Rms Roughness ~ 45Å
(25μm2)
• Transistor behavior ≤ 300°C
• Mild deposition conditions
• Direct deposition of metal
oxo-hydroxide
•Low mobility/current density
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Rapid Low Temperature Reaction:
Aluminum Oxide Phosphate (AlOP)
Al2O3 Corundum
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AlPO4 Berlinite
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Rapid Low Temperature Reaction:
(AlOP)
Precursor
Al(OH)3(s) + 2HCl(aq) +½H3PO4(aq)
95º C
Al(OH)Cl2(aq) + ½H3PO4(aq) +2H2O
Polymerization
Al(OH)Cl2(aq) + ½H3PO4(aq)
275º C
AlO3/4(PO4)1/2(s) + 2HCl (g) + ¼H2O
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Rapid Low Temperature Reaction:
(AlOP)
Results
• Amorphous AlO3/4(PO4)1/2 dielectric films
• Rms roughness 2.2Å (25 μm2)
• Low temperature dehydration (275º C)
• Highly uniform dielectric properties
• Mechanically robust films
• Deposition pH 3-4
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Rapid Low Temperature Reactions:
Chemical Implications
•Aluminum Oxide Phosphate:
Widely applicable chemistry - Building a “Tool Box”
•Tin Oxide Phosphate:
Seeking intelligent deposition routes
•Zinc Oxide:
Direct chemical deposition of the desired material
•Hafsox/La:
Functional gate dielectric
Entirely Solution Processed Devices
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Device Characterization
•
Parallel-Plate Capacitor or MIM (Metal Insulator
Metal)
– Device Structure
• Insulator material between two metal plates
–
MIM Characterization
• Loss Tangent
• Permittivity
• Breakdown Strength
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Dielectric Performance
Material
ATO
SiO2
Hafsox
(Thermal)
Aluminum Oxide
Phosphate
Loss Tangent at 1kHz (%)
1.36
<0.01
0.30-0.50
1.20
Permittivity @ 1kHz
16.25
3.9
9-12
4.30
Breakdown Strength (MV/cm)
4.26
8.5
Sample Size
–
Hafsox
4-5
References
–
• 36 substrates, 216 devices
–
Aluminum Oxide Phosphate
ATO
• Jeff Bender
–
• 1 substrate, 6 devices
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4.94
SiO2
• Handbook of Thin Film
Technology
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Device Characterization
•
Thin Film Transistor
– Device Structure
• Bottom-Gate
Physical vapor deposition
Solution based deposition
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Substrate provided by HP
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Device Characterization
•
Thin Film Transistor Characterization
– ID-VDS
• DC
• Qualitative Characteristics
• Current Drive
–
ID-VGS
• DC
• Mobility (VDS = small, typically 1 V)
• Von
– Depletion vs. Enhancement Mode
• On-to-off Ratio (VDS = large, typically 30 V)
– Device Geometry
– Gate Leakage
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Solution Deposited Thin Films
Device Type
Motivation
PVD zinc tin oxideHafsox
Show feasibility of Hafsox as gate
insulator
Tin oxide phosphate Solution based channel deposition
Zinc oxide
Solution based channel deposition
Zinc oxide-Hafsox
Low temperature integration of solution
processed channel and gate insulator
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Sputtered ZTO on Hafsox
-Annealed at 300 ˚C
Annealed at 300 °C
μinc=6.5
μavg=4.7
VGS = 0 to 10 V
in 1V Steps
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Solution Deposited Thin Films
Device Type
Motivation
PVD zinc tin oxideHafsox
Show feasibility of Hafsox as gate
insulator
Tin oxide phosphate Solution based channel deposition
Zinc oxide
Solution based channel deposition
Zinc oxide-Hafsox
Low temperature integration of solution
processed channel and gate insulator
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Spin-Coated Tin Oxide Phosphate
Annealed at 500 °C
VGS = 0 to 40 V
in 5V Steps
Max
VON = -7V
Current
Drive of
225nA
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On-to-Off ~104
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Solution Deposited Thin Films
Device Type
Motivation
PVD zinc tin oxideHafsox
Show feasibility of Hafsox as gate
insulator
Tin oxide phosphate Solution based channel deposition
Zinc oxide
Solution based channel deposition
Zinc oxide-Hafsox
Low temperature integration of solution
processed channel and gate insulator
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Spin-Coated Zinc Oxide on SiO2
Annealed at 600 °C
Max
Current
Drive of
37μA
VGS = 0 to 40 V
in 5V Steps
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Solution Deposited Thin Films
Device Type
Motivation
PVD zinc tin oxideHafsox
Show feasibility of Hafsox as gate
insulator
Tin oxide phosphate Solution based channel deposition
Zinc oxide
Solution based channel deposition
Zinc oxide-Hafsox
Low temperature integration of solution
processed channel and gate insulator
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Spin-Coated Zinc Oxide on Hafsox
Annealed at 300 °C
Max Current
Drive of 1μA
VGS = 0 to 40 V
in 5V Steps
VON = -24V
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On-to-Off ~104
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Inkjet Deposition
Yu-Jen Chang
Outline
Semiconductor Material – Zinc Indium Oxide (ZIO)
Previous work
Channel layer patterning
Device fabrication and characterization
Precursor solution study
Dielectric Material - Hafsox
Precursor solution
Device fabrication and characterization
Summary and ongoing work
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Zinc Indium Oxide (ZIO)
Previous work
Spin coating
 Indium and zinc chlorides were combined with gluconic
acid to form the aqueous precursor solution.
 The precursor was spin-coated and heated at 130ºC.
Additional heating was employed at temperatures in the
range 300-575ºC.
 The depletion –mode ZIO transistor had shown an
incremental mobility of ~ 0.05 cm2/V-sec at Vgs = 20 V.
Von ~ -20 V and an on-to-off ratio of approximately 103.
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Zinc Indium Oxide (ZIO)
Previous work
Inkjet printing
 ZIO thin films using diluted stock solution were prepared via
inkjet printing.
 Bottom gate ZIO MISFETs on oxidized silicon coupons were
fabricated with different post annealing temperature ranging
from 300 to 600oC.
 Light source was employed to stabilize the thin film and
overcome the de-wetting problem.
 No gate-modulated transistor behavior were obtained for Inkjet
printed ZIO TFT devices.
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Zinc Indium Oxide (ZIO)
Inkjet printing
Growth Mechanism
Metal halide
precursor solution
Inkjet printing
O2 source +H2O
Acetonitrile
Evaporation
Post annealing
Desorption
Liquid thin film
Metal oxide
Si coupon substrate
Si coupon substrate
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HCl
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Zinc Indium Oxide (ZIO)
Inkjet printing
 An alternative ink solution was prepared by dissolving
0.015M of ZnCl2 and 0.015M of InCl3 in 25ml acetonitrile
at room temperature.
 First pass bottom gate ZIO MISFET was fabricated.
Gate-modulated transistor behavior was obtained but
large gate leakage currents were found.
 To avoid this problem is to pattern the semiconductor
channel layer
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Zinc Indium Oxide (ZIO)
Channel layer patterning
~12 mm
Inkjet Printing
3
Device
S/D contacts
10
Characterization
15 mm

Stripe patterned ZIO thin films were thermal ink-jetted on
Si/SiO2 test coupon to fabricate ZIO TFTs.
 Gate leakage current was significantly reduced by 2 to 3
orders of magnitude for stripe patterned (~3mm x12mm)
ZIO TFTs (1e-10~1e-13 Amp at Vg=0V) comparing to
non-stripe patterned ones.
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Zinc Indium Oxide (ZIO)
Device fabrication and characterization

ZnCl2 and InCl3 were dissolved in 25 ml of acetonitrile
with a molar ratio of 1 to 1 (0.015M) as precursor solution
for ink jet printing.

The modified HP 1220C inkjet printer was used to print
the thin ZIO layer.

Working ZIO TFTs were obtained from films annealed at
325oC, 400oC, 600oC, and 800oC (in acetonitrile); 375oC
(in ethanol)
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Zinc Indium Oxide ID-VDS Characteristic
(600 ºC, Acetonitrile)
2.0E-05
2.5E-06
W/L = 7
L = 200 um
ID (A)
1.5E-06
1.0E-05
1.0E-06
5.0E-06
IG(A)
2.0E-06
1.5E-05
5.0E-07
0.0E+00
0.0E+00
0
10
20
30
VDS (V)
• I-V characteristics for inkjet ZIO TFTs annealed at 600 ºC for 1 hour
using acetonitrile as the precursor solvent.
• 2015
W/L=7 and µinc ~0.7 cm2/V-s.
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Zinc Indium Oxide ID-VDS Characteristic
(800 ºC, Acetonitrile)
1.E-09
6.E-07
W/L = 7
L = 200 um
1.E-09
4.E-07
8.E-10
3.E-07
6.E-10
2.E-07
4.E-10
1.E-07
2.E-10
0.E+00
0.E+00
0
20
10
IG(A)
ID (A)
5.E-07
30
VDS (V)
• I-V characteristics for inkjet ZIO TFTs annealed at 800 ºC for 1 hour
using acetonitrile as the precursor solvent.
• 2015
W/L=7 and µinc ~0.013 cm2/V-s.
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Zinc Indium Oxide ID-VDS Characteristic
(375 ºC, Ethanol)
8.E-09
7.E-09
W/L = 7
L = 200 um
6.E-08
6.E-09
5.E-09
4.E-09
3.E-09
ID (A)
5.E-08
4.E-08
3.E-08
2.E-08
IG(A)
7.E-08
2.E-09
1.E-09
0.E+00
1.E-08
0.E+00
0
10
20
30
VDS (V)
• I-V characteristics for inkjet ZIO TFTs annealed at 375 ºC for 1 hour
using ethanol as the precursor solvent.
• 2015
W/L=7 and µinc ~0.005 cm2/V-s.
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Zinc Indium Oxide (ZIO)
SEM analysis on a working TFT using inkjet ZIO thin film
The top view image of the
gate region
The cross-sectional view
of the gate region,
the thickness of ZIO thin
film is ~10 to 15nm.
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The top view image of the
region outside the device
gate
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Zinc Indium Oxide (ZIO)
(a) AMD cleaning
Precursor solution study
Precursor solutions listed in Table were inkjet printed on Si/SiO2 test coupon
for film formation and patterning study.
Solvents
Film Quality
(b) AMD cleaning
Water/Acetonitrile
Poor
(10 to 90% of water)
Dewetting
Isolated dots
Water/Ethanol
(10 to 90 % of water)
Acetonitrile

Fair
Dots on the surface
Fine
Tiny Dots on the surface

Ethanol
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Patterning
No pattern
Fine
Solution spread out
No pattern
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Zinc Indium Oxide (ZIO)
Precursor solution study
Volumetric ratios for Ethanol/Acetonitrile
5/95%
14.66o
10/90%
25/75%
10.27o
<10o
Increasing contact angle
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50/50%
75/25%
<10o
<10o
Not much different by changing
Ethanol/Acetonitrile volumetric ratio
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Zinc Indium Oxide (ZIO)
Summary
Processing Method
Spin coating
Inkjet printing
Patterning
Non-available
Available
Device Type
Depletion-Mode
Enhancement-Mode
Device Performance
µinc ~0.05 cm2 V-1 s-1
µinc ~0.7 cm2 V-1 s-1
Ongoing work
Solvent
Thickness
Morphology
Zn/In
ratio
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Hafnium Oxide Sulfate (Hafsox)
Precursor solution ,Device fabrication and
characterization

HfOCl2 ,,La2(SO4)3 ,H2SO4 and DI water was used for
preparing the Hafsox precursor solution for spin coating
process.

Diluted precursor solution suitable for inkjet printing process
was prepared by 0.01M HfOCl2 and 0.002M H2SO4 in
solution of water/ethanol (ethanol is 10% of the solution
volume).

Single layer and multilayer deposition were performed
through inkjet printing process for depositing Hafsox thin film.
Hafsox thin film deposition via inkjet printing on Tantalum
surface was performed and device was tested by MIM 54
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capacitor structure.

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Hafnium Oxide Sulfate (Hafsox)
Scanning Electron Microscopy (SEM) characterization
Defects and pinholes were observed in SEM micrograph
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Hafnium Oxide Sulfate (Hafsox)
Pen autopsy images of a used inkjet cartridge after
printing Hafsox precursor solution
Completely closed nozzle
with precipitate
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Resistor
surface with
precipitate
Partially closed nozzle
with precipitate
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Hafnium Oxide Sulfate (Hafsox)
Summary

Inkjet printed Hafsox dielectric layer could not pass the
MIM test for our study.

SEM measurements indicated pin holes and defects on
inkjet printed Hafsox thin films.

Hafsox precursor solution had damaged and blocked the
inkjet cartridge nozzles via precipitate around the nozzle
opening and the resistors.

This Hafsox precursor solution is not compatible with
current inkjet printing system.
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4/5/2005
Material Exploration
Hai Chiang
Jason Stowers
Amorphous Oxide Semiconductors
•
n-type amorphous oxide semiconductors
–
Composed of heavy-metal cation(s) with
(n-1)d10ns0 (n≥4) electronic configuration
• conduction band primarily derived of
spherical s orbitals
• cation examples include In, Zn, Sn, Ga, Cd, etc.
• material example: indium oxide doped with tin (ITO)1
–
Methods employed in exploration:
• rf sputtering from ceramic targets
• shadow mask pattering
• bottom-gate structures fabricated on oxide Si coupons.
1. Y. Shigesato and D. C. Paine, Appl. Phys. Lett. 62, 1268 (1993)
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Inorganic Devices via Additive Processing
Future Work:
• Continue efforts on development of oxide electronics
• expand learnings on device performance of
solution processed vs. physical processed devices
• demonstrate high mobility p-type behavior
• demonstrate dielectric permittivity ~ 50
• demonstrate transistor channel mobilites ~ 50
• Extend program to include nonoxide channel materials
• initial efforts on crystalline and amorphous
tellurides
• demonstrate transistor channel mobilities ~ 100 60
Previously explored materials:
Zinc tin (indium) oxide
Temp
(C)
Zinc tin oxide
(1:1 mol)1,2
Zinc indium oxide
(2:1 mol)2,3
inc
(cm2/V-s)
Von
(V)
inc
(cm2/V-s)
Von
(V)
RT
-
-
0.4
10
200
<0.01
25
2
-2
400
16
0
40
-35
600
26
-1
28
-50
1. R. Hoffman, HP internal document, WKRP, Oct. 22, 2003
2. H. Chiang, J. Wager, R. Hoffman, et al., Appl. Phys. Lett. 86, 013503 (2005)
3. H. Chiang and R. Hoffman, HP internal document, WKRP, Aug. 19, 2004
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4. N.Dehuff, E. Kettenring, D. Hong, et al., J. Appl. Phys. 97, 064505 (2005)
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8.E-04
log (ID(A))
Increasing VGS
ID (A)
6.E-04
4.E-04
2.E-04
0.E+00
0
10
20
30
0
-2
-4
-6
-8
-10
-12
0
-2
-4
-6
-8
-10
-12
W/L = 5
L = 200 µm
VDS = 30 V
-10
0
10
20
30
log (|IG|(A))
Indium gallium oxide (1:1 mol):
DC Electrical Characteristics
40
VGS (V)
VDS (V)
VGS = 0 to 30 V
in 10 V steps
• Channel layer subjected to 600 ºC anneal.
• ITO source/drain contacts.
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Indium gallium oxide (1:1 mol):
Channel mobility characteristic
W/L = 5
VDS = 1 V
15
µinc ~ 16 cm2/Vsec
2
inc (cm /V s)
20
10
5
0
-10
0
10
20
30
40
VGS (V)
•
Fairly ideal, increases then saturates.
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Indium gallium oxide (1:1 mol):
Performance
Temp
(C)
Zinc tin oxide (1:
1 mol)
Zinc indium
oxide (2:1 mol)
Indium gallium
oxide (1:1 mol)
inc
(cm2/V-s)
Von
(V)
inc
(cm2/V-s)
Von
(V)
inc
(cm2/V-s)
Von
(V)
RT
-
-
0.4
10
-
-
200
<0.01
25
2
-2
-
-
400
16
0
40
-35
7
7
600
26
-1
28
-50
15
1
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Conclusions and path forward
Conclusions:
• Indium gallium oxide with qualitatively ideal ID-VDS
characteristics.
• Channel mobility characteristics comparable to zinc tin
oxide, but lower magnitude.
• Additional process flexibility - indium gallium oxide
etches in HCl.
Path Forward:
• Explore stoichiometric variations of indium gallium oxide
– literature suggests that performance increases with
indium concentration.1
• Optimize deposition parameters.
1.
T. Minami, Y. Takeda, et al., JVST A, 15, 958 (1997).
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P-Type Material Investigation
•
•
•
•
Recent work in this group has found several n-type
materials with an amorphous crystal structure. 1,2
We hope to use additional properties of amorphous
structure as a route to forcing candidate materials toward
p-type behavior.
The materials will be deposited amorphously by using low
substrate temps during e-beam deposition.
Crystallization will be frustrated through addition of ~10 to
40% Zn, In, Sn or combination there of.
1.
Dehuff, N. L.; Kettenring, E. S.; Hong, D.; Chiang, H. Q.; Wager, J. F.; Hoffman, R. L.; Park, C.-H.; Keszler, D. A..
Transparent thin-film transistors with zinc indium oxide channel layer. Journal of Applied Physics (2005), 97(6)
2.
Chiang, H. Q.; Wager, J. F.; Hoffman, R. L.; Jeong, J.; Keszler, D. A.. High mobility transparent thin-film transistors with
amorphous zinc tin oxide channel layer. Applied Physics Letters (2005), 86(1)
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Candidate materials;
Bi2O3 and Sb2O3
•
•
Known Materials
– ZnO, Zn2+; [Ar] 3d10 4s0
– Cu2O, Cu1+; [Ar] 3d10 4s0
n-type
p-type
Candidate materials
– Bi2O3, Bi3+; [Xe] 5d10 6s2
– Sb2O3, Sb3+; [Kr] 4d10 5s2
p-type?
p-type?
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Energy Band Levels in Bi2O3 and Sb2O3
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Local metal atom coordination
Distorted Octahedral Environment for Bi in Bi2O3,
bond length ~2.1-~3 Ang
Proposed regular Octahedral Environment for Bi in
amorphous Bi2O3 , bond length 2.4 Ang
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Bi2O3 Band Structure
6P
2P
6S
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Progress To Date
•
•
•
Depositions are completed for
compositional arrays with Bi2O3 and Sb2O3
Optical and electrical measurements are
underway
Crystallization temperature being
determined
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Summary of Solution
Deposited Film Strategies
• Semiconductor films will be made more
dense to achieve higher mobility.
• Dielectric permittivity will be increased
through a layering technique.
• Buffer films will be employed to improve
film interfaces.
72
Summary of solution
deposited thin films
•
•
•
•
•
Modified Hafsox was demonstrated as a gate dielectric
AlOPhos exhibited uniform MIM breakdown characteristics
TOP by solution deposition was demonstrated as a channel
layer
ZnO by solution deposition was demonstrated as a channel
layer
Solution deposited channel and dielectric layers were
integrated in transistor devices
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Backup Slides
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Zinc Indium Oxide (ZIO)
1.80E-06
1.60E-06
Vg = -20
Vg = -16
1.40E-06
Vg = -12
1.20E-06
Ids (A)
Vg = -8
1.00E-06
Vg = -4
8.00E-07
Vg = 0
Vg = 4
6.00E-07
Vg = 8
4.00E-07
Vg = 12
2.00E-07
Vg = 16
Vg = 20
0.00E+00
-2.00E-07
0
5
10
15
20
25
30
35
40
Vds (V)
Drain current – drain voltage characteristics for a spincoated ZIO transistor with a W/L ratio of 7 and 100 nm of
thermal SiO2 as the gate dielectric.
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Zinc Indium Oxide (ZIO)
Precursor solution study
Contact angle measurement
100%-acetonitrile
100%-Ethanol
Θ
Contact angle – 51o
Contact angle - ~ 0o
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Hafnium Oxide Sulfate (Hafsox)
Solubility of aqueous solution of HfOCl2 and H2SO4
0.1
total Sulfate (M)
0.08
0.06
0.04
0.02
0
0
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0.02
0.04
total Hafnium (M)
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0.08
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Hafnium Oxide Sulfate (Hafsox)
Atomic force microscopy (AFM) characterization
The 2-D AFM micrograph and roughness
analysis for a single coat Hafsox thin film
with July
ave.18,roughness
~0.688nm.
2015
July 18, 2015
The 3-D AFM micrograph for a single coat
Hafsox thin film with thickness around 35nm.
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Backup Slides: ZTO 700 ºC XRD
Zn2SnO4 (311)
1000
Counts
Zn2SnO4 (511)
Zn2SnO4 (531)
500
Zn2SnO4 (220)
Zn2SnO4 (222)
Zn2SnO4 (533)
0
20
30
40
50
60
70
Position - 2 (°)
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Reference: Periodic Table
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