Post on 02-Jun-2018
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8/10/2019 TFTs Process Flow
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Process FlowMetal Oxide Thin Film Transistors
Fabrication
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N+ Si wafer
Gate insulator
Active layer
S D
N+ Si wafer
Gate insulator
Active layer
N+ Si wafer
Gate insulator
N+ Si wafer
Thermal oxidation
Spin coating
Shadow mask(Sputter, Evaporator)
Annealing
(FGA, O2)
Cleaning
(DHF 200:1)
Sample & solution preparation
1. Wafer cutting : 1.8 x 1.8 cm
Using the diamond scribe to cut the wafer into square
pieces.
2. Cleaning process:
No. Cleaning solutionTemp.
(C)
Time
(mins.)
1 Acetone 25 5
2 Ethanol 25 5
3 DI Water 25 5
Cleaning solution (acetone, ethanol and DI
water) and ultra-sonic cleaner
3. Using N2gun to dry the wafers
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4. Solution preparation:
Stirring the raw solutions by ultra - sonicator and
mixing machine in 5 mins for each step.
Mixing the solutions with the ratio calculated by theequation below by mixing machine:
CuO/NiOsolution calculation:
CuO/NiO(20%)+MIBK/MEK (+Silicate binder) = a%
% =
100%
N+ Si wafer
Gate insulator
Active layer
S D
N+ Si wafer
Gate insulator
Active layer
N+ Si wafer
Gate insulator
N+ Si wafer
Thermal oxidation
Spin coating
Shadow mask(Sputter, Evaporator)
Annealing
(FGA, O2)
Cleaning
(DHF 200:1)
Solutions: CuO(20%), NiO 10%, Silicate
bider, MIBK, MEK, Hybrid binderMicro electronic scales
Mixing machine
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N+ Si wafer
Gate insulator
Active layer
S D
N+ Si wafer
Gate insulator
Active layer
N+ Si wafer
Gate insulator
N+ Si wafer
Thermal oxidation
Spin coating
Shadow mask(Sputter, Evaporator)
Annealing
(FGA, O2)
Cleaning
(DHF 200:1)
Mixing Solution Calculating
1. CuO solution
20 % =
+ 100%
% =
+ 100%
Where: MMIBK= MMIBK + MMIBK- MMIBK: Mass of MIBK in the initial solution (CuO 20% + MIBK)
- MMIBK: Mass of MIBK in the subsequent solution (CuO a% + MIBK)- MMIBK: Mass of MIBK which is added to dilute the (CuO 20% +
MIBK) solution to (CuO a% + MIBK) solution
Taking 50g (MCuO+MMIBK) to calculate the solution
= 0.5
In the other hand, we have:
= 2 = 50 2.5 CuO 1% = 47.5g MCuO20%+MIBK= 2.5g CuO 5%
= 37.5g MCuO20%+MIBK
= 12.5g
CuO 10% = 25g MCuO20%+MIBK= 25g
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N+ Si wafer
Gate insulator
Active layer
S D
N+ Si wafer
Gate insulator
Active layer
N+ Si wafer
Gate insulator
N+ Si wafer
Thermal oxidation
Spin coating
Shadow mask(Sputter, Evaporator)
Annealing
(FGA, O2)
Cleaning
(DHF 200:1)
Mixing Solution Calculating
1. NiO solution
10 % =
+
100%
% =
+ 100%
Where: MMEK= MMEK + MMEK
Taking 50g (MNiO+MMEK) to mix the solution
= 0.5In the other hand, we have:
= 4.5 = 50 5
NiO 1% = 45g MCuO20%+MIBK= 5g NiO 5% = 25g MCuO20%+MIBK= 25g
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N+ Si wafer
Gate insulator
Active layer
S D
N+ Si wafer
Gate insulator
Active layer
N+ Si wafer
Gate insulator
N+ Si wafer
Thermal oxidation
Spin coating
Shadow mask(Sputter, Evaporator)
Annealing
(FGA, O2)
Cleaning
(DHF 200:1)
Spin coater(ACE-200)
Spin Coating:
CuO/NiO deposition by Spin Coating
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N+ Si wafer
Gate insulator
Active layer
S D
N+ Si wafer
Gate insulator
Active layer
N+ Si wafer
Gate insulator
N+ Si wafer
Thermal oxidation
Spin coating
Shadow mask(Sputter, Evaporator)
Annealing
(FGA, O2)
Cleaning
(DHF 200:1)
Top electrode depositing by Sputtering or
CVD
1. Applying shadow mask:
2. Depositing by Sputtering or CVD:
Chemical Vapor Deposition System /
Annealing system (FGA, O2)
Sputtering System
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Experimental plan
http://localhost/var/www/apps/conversion/tmp/scratch_4/TFT%20experiment%20plan%20table(modification).xlsxhttp://localhost/var/www/apps/conversion/tmp/scratch_4/TFT%20experiment%20plan%20table(modification).xlsx8/10/2019 TFTs Process Flow
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Measurement Methods
1. Sheet resistance measurement by Four-point Probe Station
Sheet resistance measurement on the solution processed NiO TFT
Four-point Probe Station System0.2 0.3 0.4 0.5 0.6 0.7
40
60
80
100
120
140
160
180
Sheetresistance(
G/sq.)
V(V)
0 10 20 30 40 50
40
60
80
100
120
140
160
180
Sheetresistance(
G/sq.)
I(pA)
2. Surface testing by Optical Microscope
Optical Microscope StationOM measurement on the Sputtering
samples
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Measurement Methods
3. Deposition layer thickness by FE-SEM
FE-SEM System Birds eye view FE-SEM images of the CuxO films formed by spin coating
with silicate binder, showing the thickness of 40 - 240 nm CuxO.
4. Composition of the samples by XRD:
X-ray DiffractionSystem
XRD pattern of (CuO 20% + MIBK) and the CuO nano particles from Ditto
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Measurement Methods
5. Samples surface at nanoscale by AFM
Atomic force microscopy system
AFM image if the CuO spin coating sample
which is spun at 6500 rpm