advisor : professor guey-sheng liou reporter : ming-chi tsai date : 2013/11/15 1 j. mater. chem. c,...
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Polyimide memory: a pithy guideline for future applications
Advisor : Professor Guey-Sheng Liou
Reporter : Ming-Chi Tsai
Date : 2013/11/15
J. Mater. Chem. C, 2013, 1, 7623-7634, G. S. Liou* et al.
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Outline
Introduction
Experiment
Results and Discussion
Summary
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Introduction
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Polymer memory devices
Advantages :
1) Low cost
2) Solution processability
3) Flexibility
4) 3D stacking devicePolyimide is one of the most suitable material for memory
1) Thermal stability
2) Chemical resistance
3) Mechanical strength
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Fabrication process of Polymer memory devices
J. Mater. Chem. C, 2013, 1, 7623-7634, G. S. Liou* et al.
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Principle
J. Am. Chem. Soc., 2006, 128, 8732-8733, En-Tang Kang* et al.
1st sweep : 0~4V an abrupt increase in current observed at 3.2V (writing)2nd sweep : 0~4V (reading)3rd sweep : 0~-4V an abrupt decrease in current observed at -2.1V (erasing)4th sweep : 0~-4V OFF state5th sweep : 0~4V (rewriting)6th sweep : 0~4V (reading)7th sweep : 0~4V turn off external power 1 min device turned off (erasing) and (rewriting)8th sweep : (reading)Memory type : DRAM
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Principle
Field induced CT theory
1. Conformational change
2. LUMO Energy level
3. Dipole moment
4. Large conjugation
J. Am. Chem. Soc., 2006, 128, 8732-8733, En-Tang Kang* et al.
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Experiment
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Polyimide synthesis
One-step polycondensation
Two-step polycondensation
Shahram Mehdipour-Ataei*, et al., Iranian Polymer Journal, 2008, 17, 95-124
O O
O
O
O
Odianhydride
NH2RNH2
diamine
N N
O
O
O
O
R
nPolyimide
m-cresolIsoquinoline
ArAr
O O
O
O
O
O
NH2RNH2
HN
O
HOOC
COOHHN
OR
ndianhydride diamine Polyamic acid
Chemical imidizationThermal imidization
N N
O
O
O
O
R
nPolyimide
DMAc
(Acetic anhydride, Pyridine)
(Heat)
Ar Ar
Ar
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Results and Discussion
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Volatile DRAM and SRAM properties
J. Appl. Phys., 2009, 105, 044501, En-Tang Kang* et al.
1st sweep : 0~5V 2.7V (writing)2nd sweep : 0~5V (reading)3rd sweep : 0~-2V -0.9V (erasing)4th sweep : 0~-2V OFF state5th sweep : 0~5V (rewriting)6th sweep : 0~5V (reading)7th sweep : 0~5V power off 1 min (erasing) and (rewriting)8th sweep : (reading)Memory type : DRAM
3rd sweep : 0~-6V -0.9V (erasing) -2.3V (writing)
Can be written bidirectionally
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Volatile DRAM and SRAM properties
1st sweep : 0~4V 2.3V (writing)2nd sweep : 0~4V (reading)3rd sweep : 0~-4V (reading) nonerasable4th sweep : 0~-4V power off 4 mins (rewriting) 5th sweep : 0~-4V (reading)6th sweep : 0~-4V power off 4 mins (rewriting) Memory type : SRAM
Chem. Mater., 2009, 21, 3391–3399, En-Tang Kang* et al.
Good stability when operated time
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Volatile DRAM and SRAM properties
PI → PADARM → SRAM J. Mater. Chem., 2012, 22, 14085, G. S. Liou* et al.
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Volatile DRAM and SRAM properties
PA (SARM device)Block the occurring of back CT
1. Higher dipole moment2. More nonplanar
Lower switching on voltage -3.3V3. Higher HOMO energy level4. Fewer intermediate LUMOs
Stability testBoth PI and PA memory devices
are stability when operating
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Non-volatile FLASH and WORM type memory properties
Take APTT-6FDA for example1st sweep : 0~4V 1.6V (writing)2nd sweep : 0~4V power off 10 mins (reading)3rd sweep : 0~-6V (reading & erasing) -3.2V4th sweep : 0~-6V OFF state5th sweep : 0~4V (rewriting)6th sweep : 0~-4V power off 10 mins (reading) Memory type : Flash memory
Macromolecules, 2009, 42, 4456–4463, Mitsuru Ueda*, W. C. Chen* et al
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Non-volatile FLASH and WORM type memory properties
J. Mater. Chem., 2012, 22, 14085, G. S. Liou* et al.
Write Once Read Many times (WORM)1. Nonerasable2. Highest dipole moment
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Non-volatile FLASH and WORM type memory properties
From Volatile to Nonvolatile by Perylene Diimide Composition in Random Copolymer
Donor Acceptor
The (PBI-0, PBI-1, PBI-2.5) and (PBI-5, PBI-10) devices provided volatile and nonvolatile WORM behavior, respectively.
Macromolecules, 2012, 45, 4556, Mitsuru Ueda*, W. C. Chen*, C. L. Liu* et al.
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Summary
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Summary
3D structure (192 cells)
Flexible
1. Devices structure and operating mechanism of the memory device is quite simple2. Low processing cost3. Show extremely high endurance during long term operation
In future application of PI as a good memory
device material
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THANKS FOR YOUR ATTENTION
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