Post on 20-Feb-2023
2 Merck Material for Micro LED Technology | 2017
Merck’s Advanced Materials for Micro LED Technology
Micro LED Technology Challenges
Source: LEDinside, January 2017
MO Precursor
Photoresist
QD-MaterialPhosphor
SOG, SOHG
Materials
Barrier Novel Binder
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Merck Sigma Precursor (former Aldrich Hitech)
Main metal organic precursors in special containers (0,05-7,4kg)
Element Metalorganic source
Application
CVD Doping Oxide
Al Trimethylaluminuim (TMAL) ◎ ◎
InTrimethylindium (TMIN) ◎ ◎ ◎
Solution TMI (TMIS) ◎ ◎ ◎
Mg
Bis(cyclopentadienyl)magnesium (CPMG)
◎ ◎
Soultion CP2MG (CPMS) ◎ ◎
GaTrimethylgallium (TMGA) ◎
Triethylgallium (TEGA) ◎
ZnDimethylzinc (DMZN) ◎ ◎ ◎
Diethylzinc (DEZN) ◎ ◎ ◎
CCarbon tetrabromide (CBR4) ◎ ◎
Carbon trichlorobromide (BTCM) ◎ ◎
As Trimethylarsine (TMAS) ◎
P Tertiarybutylphosphine (TBPH) ◎
Key Benefits
• Lowest impurity/oxygen level
• World wide supply network
• Customer/OEM container design
• 100% material usage by using in-series connecting kit
Proven history in organometallics for the last30 years
Merck Material for Micro LED Technology | 2017
Merck Material for Micro LED Technology | 2017
Merck Sigma Precursor (former Aldrich Hitech)
Particle measurement - Purge with high pressure of N2
190ml 400ml 930ml 1200ml 2780ml 5300ml
Par
ticl
e co
un
ts (
au)
Bubbler volume
After N2 purge
0.1μm 0.2μm 0.3μm 0.5μm 1.0μm
190ml 400ml 930ml 1200ml 2780ml 5300ml
Par
ticl
e co
un
ts (
au)
Bubbler volume
Before purge
0.1μm 0.2μm 0.3μm 0.5μm 1.0μm
Before purge After N2 purge
bubbler volume sensitive Non-sensitive
particles for 5L bubbler >11,000 <1
particles >1 μm Yes Zero
Particles must to be controlled in mass production of making advanced devices, like MicroLED.
4
Factor ~ 0.001
Moisture control
Bubbler (au)
Before treatment After treatment
Moisture trend of OM470
Before
Maximum moisture level >2000 ppb.
Larger bubbler size, higher moisture levels. (data not shown here)
After
Lower moisture (<200ppb)
Small STDEV
Not relative to bubbler size (up to 8L)
Bubbler wet cleaning
Bubbler dry cleaning Special
treatment
He leak check
5
He leak check
(Previous SOP)
(Current SOP)
Merck Material for Micro LED Technology | 2017
Merck Sigma Precursor (former Aldrich Hitech)
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LED Photoresist Line Up
Merck’s High Performance & Quality Photoresists for the LED Chip Process
120 mm FT
10 mm FT
Merck GXR for PSS process
− High etch resistance and wide DOF
− Further improved version GXR-601 M1
Merck Thick-Film PR for advanced applications
− e.g. Flip-Chip, Vertical Chip process
− Plating application
− Film thickness 5 ~ 120 mm
Merck SLD for ITO/SiO2 and MESA etch
− Versatile and high throughput
− Excellent adhesion
Merck nLOF, LOR for Metal Lift-Off
− High aspect ratio
Merck Negative-Tone PR (under development)
− Metal Lift-Off with undercut enhancement
− High-temperature resistance
10mm
5mm
5mm
Merck Material for Micro LED Technology | 2017
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Merck Thick Film Photo-resist
Product Line up ~20um
Merck Material for Micro LED Technology | 2017
SOG Introduction
Transparent Dielectric: Silicon-Organic-Glass (SOG) Material
SOG coating: transparent planarization layers for thin-film transistor (TFT) backplanes in displays
before planarization
after planarization with SOG
SOG• Thermal durability (>350ºC)• Optical transparency (1h @ 300ºC)
• Curing >200ºC• Excellent planarization
• Si-based polymer material basis
8 Merck Material for Micro LED Technology | 2017
LED Chip Periphery & PackagingPhoto-Structurable SOG Material
(1) Coating & Exposure
(2) Development
(3) Post Bake
10µm
5µ
m
SOG
No etching process needed
Key Benefits
3
2
1Highly transparent material ( 300°C)
Thermal durability ( 300°C)
Litho-type (i-line) saves process steps (features < 2mm)
Litho Process
9 Merck Material for Micro LED Technology | 2017
LED Chip Periphery & PackagingPhoto-Structurable SOG Material
5µm
• FT: up to 3-8mm
• Feature size: down to 1.5mm
(i-line exposure)• Enabled structures:
- Lines & pillars- Trenches & holes
• Litho type:
- Positive tone- Negative tone
Curing conditions: 250°C
10 Merck Material for Micro LED Technology | 2017
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Transparency and Thermal Stability of SOG Material
High Thermal Stability
TGA: no weight loss up to 300°C
(after curing 60min@250°C)
60min @ 400°C
60min @ 450°C
Negative-tone SOG
High Optical Transparency
Transparency >99.8%@400nm after
high-temperature bake (1mm thickness)
Non-photosensitive SOG
Positive-tone SOG
Negative-tone SOG
Highly Transparent Dielectrics for Optical Applications
Tran
sm
itta
nce
Merck Material for Micro LED Technology | 2017
Merck Material for Micro LED Technology | 201712
Highly Transparent Dielectrics for Optical Applications
Lithographic SOG and SOHG (Hybrid) Material
Si-Based Polymer Hybrid with Organics
Litho Type POS NEG Non-PS* NEG*
Max. FilmThickness
~8 um ~3 um ~3 um ~10 um
Cure Temperature
>250°C >250°C >200°C 120-180°C
Thermal Stability
<350°C <400°C <400°C <250°C
• Opportunity: potential applications in the field of LED seen
• Light-sensitive versions: Aspect Ratio ~1:1 (g,h,i-line irradiation)
• Pure Si-polymer formulations are developed to accommodate a high-temperature process step (>280°C) such as thermal annealing
• Hybrid systems with reduced curing temperature and higher thickness (trade-off: thermal stability)
* Commercial product for FPD application.
10um dot
10um L/S
Permanent structures with SOHG materials
Permanent structures with SOG materials
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Novel binder
Best solution for LED encapsulation
Material PropertyMethyl
Silicone
Phenyl
Silicone
Merck’s
Binder
Yellowing (heat & light
fastness)
Refractive Index
Barrier Properties
Pot-Life
Merck Material for Micro LED Technology | 2017
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Color stability at high driving current in a LED package
Merck‘s Novel Optical Binder: less color shift after 1.5A/1000hr test
➢ High-temperature stability ; stable than Phenyl-Silicone
Reliability data of Merck MRI Binder vs. Phenyl-Silicone.
Ratio of Binder : Phosphor (Merck isiphor® YYG 559 200) = 1:5 w/w.
Merck Material for Micro LED Technology | 2017
Areas where Merck focuses
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OLED OPVQuantum
Dot / Rod
Increasing barrier performance needed
Merck offers
advanced formulations
enabling coatable barrier film production
Barrier films protect against
oxygen and water
26Merck Material for Micro LED Technology | 2017
Barrier Formulations
Coating Drying Cure
Roll-to-roll Processing Polysilazane barrier formulations
Barrier Film
Oven UV
Coating
Barrier
film
Cure possible by
(A) VUV or(B) steam.
16 Merck Material for Micro LED Technology | 2017
Barrier Formulations
Silicon OxyNitride Film by UV Curing
N
S iSi
N
SiN
SiN
SiN
SiN
H SiSi
H
H
H
H
H
H
HH
HH
HH
H
H
Si
H
H
N
H
H UV cure (N2)
Conditions1. Material: AZ NL120A2. Tool:10mW/cm2 172nm excimer lamp3. Atmosphere: N2
N2 in N2 out
RotaryPump Eximer Lamp
Quartz window
N2 flow: 20 Liter / min.
17 Merck Material for Micro LED Technology | 2017
Barrier Formulations
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Key take-aways
Barrier formulations
Variety of substrates –plastics or
glass
Thin layers –ideal for flexibility
Tuneable performance –adjust for your
end markets
Easy processing – does not
require vacuum
Merck Material for Micro LED Technology | 2017
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Single layer
QD or OPV requirements
Barrier
Plastic substrate
WVTR ~10-4g/m2/day
Multiple layers
OLED requirements
Plastic substrate
Barriers
WVTR <10-4g/m2/day
Barrier layer possibilities
Merck Material for Micro LED Technology | 2017
Example performancecoated barrier films made in Merck’s
R&D lab.
More details available: NAX and NL systems: L. Prager et al Thin Solid Films 570 (2014) 87-95 and N. Satake, S. Kawato, Y. Ozaki & M. Kobayashi IDW’13, FLX4-3, pp1549-1550LB200 system: internal data20
Single layer, barrier material coated on
polyethylenenaphthalate (PEN) substrate
Water Vapor Transmission Rate (WVTR) was
determined at 40℃, 90% relative humidity
Formulation CureFilm
Thickness (nm)
WVTR (g/m2/day)
Reference PEN substrate - - 10
Barrier films
NAX120 Steam 800 10-2
NL120A UV 250 10-3
LB200 UV 200 10-4
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Polysilazane formulations wet-coating (R2R) of barrier films.
Barrier performance tuneable to address different market needs, from QD barriers to OLED barriers
Formulations scaled-up and ready for market3
2
1
Barrier summary
Merck Material for Micro LED Technology | 2017
Merck Material for Micro LED Technology | 201722
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