Discover2021 Scientific ReportAdvancing theWorld’s Technologies
Through Scienceand Innovation
Materials Scienceand Analytics
Separation science
Membrane scienceand engineering
Polymer characterizationand development
Interfacial science
Source of contamination
analysis

Advanced
Materials
Materials synthesis andtailored formulation
Precision gas mixtures
Specialty coatings
Graphite, SiC, andengineered carbon
Surface prep and clean
Liquid and gas storage
and transport

Microcontamination
Control
Leading-edge liquidfiltration and purification
Gas purification atparts-per-trillion (ppt) levels
AMC solutions foradvanced fabs
Wafer and reticle handling
Fluid management,sensing, and control

Manufacturing
Excellence
Ultraclean component andmaterials manufacturing
Rapid prototyping
and customization
Leading-edge quality control
with integrated SPC
Broad global manufacturing
footprint

2

Scientific Report 2021 | Entegris, Inc.

Table of Contents
LETTER—

Welcome to Our 2021 Scientific Report...................................................... 4

ARTICLES—

Enabling the Smartphone Evolution............................................................. 6
10 Years on the Leading Edge of Technology
Advancing Autonomous Electric Vehicles................................................. 14
Smart Materials and Detailed Unit Process Design
Become Key Drivers
From Prototypes to High Volume Manufacturing ..................................20
Entegris' AM JourneyState-of-the-Art Space Optics.....................................................................26
Innovative Materials for a Challenging Environment
Doubling Down on EUV’s Defectivity Challenges...................................32
Addressing Challenges Beyond Stochastics
Delivering the Therapies of the Future.......................................................40
The Role of Aramus™ Single-use Assemblies

Entegris, Inc. | Scientific Report 2021

3

Welcome to Our
2021 Scientific Report
At Entegris, innovation is more than a business imperative. It is an existential
mandate central to our corporate PACE values and our commitment tosocial responsibility. We want innovation at Entegris to align with our value
proposition for our customers and to create broad economic value, wider
access to technology, and to improve the lives of people around the world.
As we innovate, we will strive toward excellence, realizing that excellence isa journey. It requires setting high standards for ourselves and pushing thelimits of what is deemed possible.

Among the most important questions we ask ourselves is:
Where will our next new ideas come from?
While there is no single answer to this question, at the heart of our innovation is the inspirationthat comes from a close collaboration with our customers – the world’s leading manufacturers
in highly complex industries. We focus our collective mindset as an organization on helping
these customers develop solutions that power the transformation of our cities, transportation,and healthcare as well as the way we work, learn, and live our lives. You may know Entegris
best for our innovations in the semiconductor market where we use our expertise in materials
science to solve advanced technology problems. The laptop, tablet, or phone on which you
may be reading this report was likely produced in a factory enabled by Entegris innovations.
To deliver on the promise of novel solutions to help our customers advance their manufacturing
processes and improve the performance of their products, we invest in a network of industry-leading technology centers. We locate these tech centers near where our global customers
operate and where the next generation of advanced technologies will be developed. This geographic proximity makes it possible for our engineers and scientists to engage more effectively
with our customers. It creates a shared sense of purpose and facilitates more open collaborationthat translates into shorter development cycles, accelerated ramps to high-volume manufacturing, higher yields, and, ultimately, solutions that address our customers’ challenges inreal time.
In addition, Entegris employees around the world contribute to advanced research incollaboration with world-renowned research institutes like Belgium’s imec and France’s
CEA-LETI. And in 2020, we launched a joint research laboratory with A*STAR's Singapore
Institute of Manufacturing Technology (SIMTech) to explore additive manufacturing andstate-of-the-art modeling and simulation techniques for new product development efforts.
By contributing to leading-edge research, we not only create new value, capabilities, andinnovative approaches for Entegris but also for the industries we serve.

4

Scientific Report 2021 | Entegris, Inc.

Our differentiated technologies, development speed, and unique rigor in our development
process also have opened up opportunities for us to contribute breakthrough research in ourcore semiconductor market and to create value in new areas. Over the years, we have worked
closely with leaders in the semiconductor industry and research consortia to advance EUV
lithography through the R&D process to its current expansion into high-volume production.
Today we’re witnessing radical innovations in the development, qualification, and delivery of
vaccines to fight the COVID-19 pandemic around the world. Clean, robust, and reliable solutions
developed by Entegris are helping make it possible to manufacture and safely distribute thesevaccines. We are also witnessing exciting achievements in science and engineering beyond
our planet. Entegris has contributed to advances in optics used in space with technology for
the GEMS (Geostationary Environment Monitoring Spectrometer) satellite that is being deployed
to monitor our planet’s atmosphere. And closer to home, there is a commitment to preserveand protect our planet by introducing new technologies that enable reductions in our carbon
footprint. Entegris capabilities and innovative solutions can support the demand for thesetechnologies, particularly as the automotive industry evolves toward more electrified andautonomous fleets.
This inaugural Entegris Scientific Report showcases our approach to innovations that are
addressing complex challenges in materials science that impact our daily lives. In a year thathas been so difficult for so many, we are excited to have supported the massive effort to produce the digital solutions needed to safely work and learn from home, and we are proud tohave contributed to the efforts of vaccine manufacturers who have provided hope for brighter
days ahead. These efforts are among the many contributions of the dedicated team members
throughout our global organization who overcome obstacles to tackle hard problems and tocreate the innovations that we rely upon today and those that will continue to improve andtransform our lives in the future.
Sincerely,

Bertrand Loy

James A. O'Neill, Ph.D.

President andChief Executive Officer

Senior Vice President andChief Technology Officer

Entegris, Inc. | Scientific Report 2021

5

ENABLING THE
SMARTPHONE
EVOLUTION
10 Years on the Leading
Edge of Technology
Authors: James A. O'Neill, Ph.D.
Wenge Yang, Ph.D.

Semiconductor Innovations
Power Smartphone Technology
While internet connected mobile devices have been in use
since the late 1990s, the smartphone as we know it today was
first introduced in 2007 with the announcement of the Apple
iPhone.® Since then, the smartphone has become more thanjust a useful communication gadget; it is unarguably an extraordinarily influential piece of transformational technology thathas put everything from banking to navigation in our pocket.1
Smartphone technology has become ubiquitous around theworld with an estimated 1.5B units sold per year (Figure 1),
making mobile technology a major driver of semiconductor
chip manufacturing volumes. Each year sees the introductionof new smartphone capabilities, from biometric advancements
like voice, facial, and fingerprint recognition, to improved geopositioning accuracy, enhanced mobile security, augmented
and virtual reality (AR/VR), and artificial intelligence (AI). These
new capabilities generate ever-increasing data volumes anddrive the need to process, store, and communicate that data.
Smartphone technology pushes the frontier of logic processor
performance, achievable memory density, and modem speed.
In response, increasingly complex chip designs and morechallenging device architectures are required to meet highperformance and low power needs, as well as increasing data
demands. Who doesn’t want a device that can run twelve apps
simultaneously and requires charging only once a week?
Number of Smartphones Sold to End Users Worldwide

172.38139.29122.32500

1 535.36

1 540.66

1 556.27

1 536.54

680.11750

472.00

1 000

250

1 378.72

1 244.74
969.72

1 250

296.65

Sales (Million Units)

1 500

1 495.96

1 750

1 423.90

From 2007 to 2021

20
07
20
08
20
09
20
10
20
11
20
12
20
13
20
14
20
15
20
16
20
17
20
18
20
19
20
20
20
21
*

0

*Forecast
Source: Gartner, Statista

Figure 1.
7

Historically, improvements in speed and density havebeen achieved by miniaturizing features on a chip
through advancements in photolithography. Yet thelimiting dimensions on today’s leading-edge logic chips
are approximately five nanometers: that’s roughly 40
atomic diameters (Figure 2). The industry is now facedwith the enormous challenge of engineering materials
at nearly atomic scale dimensions, and continued
optics-based miniaturization is increasingly difficult.
Therefore, other innovations are needed such as new
device architectures that are no longer limited to theplane of the wafer but rise into the vertical dimension(Figure 3). Such structures in turn require new materials
with increasingly stringent performance requirements
to enable their fabrication.

~5 nm

10 nm

2 nm

mRNA

DNA

Figure 2. Limiting dimensions on today's leading-edge logic chips
are comparable to a single strand of DNA.*

Planar Device

This innovation pushes the frontier of semiconductor
fabrication capabilities at the world’s most advanced
chip manufacturers. It also introduces a significant
amount of complexity into the fabrication process,making manufacturing yield ramps more difficult toachieve in the timeframe at which new technology
nodes are introduced. For semiconductor manufacturers that supply smartphone companies, cycles oflearning and speed to yield are key. Therefore, semiconductor process engineers place enormous emphasis
on introducing performance-enabling materials andcontrolling defects throughout their manufacturing
process. This article will examine the role Entegris
plays in enabling both performance and yield throughthe introduction of advanced high-purity materials, andthe ability to ensure the integrity of those materials
from the point where they are manufactured to where
they are used on the wafer. We will examine key elements of the smartphone platform and illustrate where
Entegris materials play an enabling role.

FinFET Device

Nanowire Device

Figure 3.

8

Scientific Report 2021 | Entegris, Inc.

Advancements in
Logic Technology

techniques using 193 nm immersion scanners, andmore recently, extreme ultraviolet lithography (EUV)
has been introduced to extend the reach of opticalscaling capabilities to pitches of approximately 26 nm.

The unrelenting demand for processor performanceby smartphone platforms rapidly motivated the needto integrate multiple application processing cores(APUs), processing cores (CPUs), graphics processing
units (GPUs), and cache memory to enable mobile
computing functions into a single chip. By 2010,leading smartphone providers started to design theirown logic processors rather than relying on chip designs
provided by traditional logic IDMs. The initial technology
was fabricated in a 45 nm node manufacturing process
by leading chip foundries. The relationship between
design shop and fab strengthened over the next 10 years
as new chip designs challenged the limits of existing
fabrication process capabilities, and guided, in largepart, the advancement of the logic process technology
roadmap (Figure 4). Over time, there developed a closeinterplay between how far design limits could be pushed
within the capabilities of a given fabrication process
technology. Today’s most advanced logic processor
used in a smartphone platform is fabricated with 5 nm
node process technology and contains 16 billion
transistors on a piece of silicon the size of a thumbnail.2
This dimensional scaling has been enabled by continued
enhancements in lithographic multi-patterning

However, further performance improvements haverequired additional innovations such as the introductionof new device architectures like FinFETs that bring theactive region of the transistor out of the plane of thesilicon wafer into the vertical dimension. This innovation
allows for better device performance at lower standby
power (lower subthreshold leakage) as compared toplanar devices – an advantage for high performance
mobile devices. However, making three-dimensional
structures on a wafer introduces new challenges tothe fabrication process such as the need to engineer
films over high aspect ratio structures. This places new
requirements on the performance of the materials usedin the fabrication process such as enhanced selectivity
or extreme conformality. For example, thickness
variations in the hafnium oxide (HfO2) gate dielectric
film over a fin structure in today’s FinFET transistor
will detrimentally affect device leakage which has an
exponential dependence on film thickness. Additionally,
any variations across the chip will broaden the thresholdvoltage (Vt) distribution making it difficult to turn off
the more than 16 billion transistors simultaneously.

Logic Process Technology Roadmap
193i

HKMG

FinFET

4G
Smartphone

AI
HPC

5G

GAAFET

40 nm

28 nm

20 nm

16 nm

7 nm

5 nm

2 nm

3 µm
1.5 µm
1.0 µm
1.2
µm

0.8
µm

0.5
µm
0.6
µm

0.35
µm

0.25
µm
0.3
µm

0.13
µm

0.18
µm

90
nm
65
nm 45
nm

1987

1989

1991

1993

1995

1997

1999

2001

2003 2005

2007

40
nm

28
nm

16
nm
20
nm

2009

2011

2013

7
nm

10
nm

2015

2017

5
nm

3
nm

2
nm

2019

Year

Figure 4.

Entegris, Inc. | Scientific Report 2021

9

Atomic layer deposition(ALD) processes are now
used in an increasing numberof critical deposition steps in
the manufacturing sequence
to address the need for conformality (Figure 5). Suchprocesses deposit material a
few atomic layers at a time
Figure 5.*
in a sequential manner until
the desired film thickness is achieved. Not only is
extreme conformality needed over very high aspectratio structures, but also critical films such as the HfO2
gate dielectric must have extremely low levels of
impurities. Entegris has patent pending technologies
surrounding this capability. Such performance requirements limit the number of metalorganic candidate
precursors that can be used in this ALD process, so
hafnium halide precursors have been adopted instead.
Historically, process engineers have preferred precursors
which are gases or liquids at room temperature due totheir ease of handling and delivery. However, the preferred precursor for the HfO2 high-k gate dielectric isa solid at room temperature. This material introduces
new challenges in process defectivity and deposition
rate due to its corrosivity, its low vapor pressure, andits tendency to entrain particulates from the reservoirof powdered HfCl4. For this reason, great effort ismade to engineer a delivery system that ensures
low defectivity and maximizes the amount of vapordelivered to the wafer surface (Figure 6).
6× higher material surface
area for vaporization

Carrier gas flow
is directed acrosssolid surface toincrease pick-up
rate of vaporizing
materialJ

Tray allows for
improved heattransfer to thematerial, resulting
in better thermal
uniformity

Figure 6. Entegris ProE-Vap solid precursor delivery vessel.

10

130
120

5

0

1.0

110

0.8

100

0.6

90
80

0.4

70

0.2

60

0

50

1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0

Specifically engineered surfaces within the vessel prevent
corrosion and the introduction of additional defects andensure maximum entrainment of precursor vapor to the wafer.

In addition, inline particle filters are added to avoid
entrainment of small particles of HfCl4 powder into
the chamber. Today, Entegris’ patented ProE-Vap®
system is the leading technology for solid precursordelivery used in critical processes for logic chips
found in most advanced smartphone platforms.

Advancements inMemory Technology
As impressive as the advancement in logic technology
designs have been over the last 20 years, advancements
in memory/storage technology found in smartphoneplatforms are equally notable. Smartphones available
around the year 2000 typically came with 8 to 16 GB
of storage while 512 GB to 1 TB of storage is available
on today’s phones. Significant improvements in camera
technology and the proliferation of video usage havebeen major drivers for this need for increased storage.
Smartphones use dedicated NAND flash technology
for storage because hard disk drives (HDD) would notsurvive the rough handling that phones are subject todaily. As in logic chips, lithographic miniaturization is
the means by which memory density was achieved in
2D flash NAND devices; however, miniaturization of
the memory cell below roughly 20 nm node is difficult
due to the need to store sufficient charge for reliable
bit information. Therefore, facing limitations in size
reduction, 2D NAND has evolved into 3D structureswith layers of storage cells stacked on top of eachother to increase storage density (Figure 7).3

Scientific Report 2021 | Entegris, Inc.

3D NAND Roadmap
256 Layers

196 layers

128 layers

128 layers

2019

2020

96 layers

64 layers
48 layers
32 layers

2015

2016

2017

2018

2021

2022

Years

Source: Tech Insights

Figure 7.

Today’s smartphones with 512 GB of storage arebased on 3D flash NAND chips with more than 100
layers. Evolution of NAND flash technology into thevertical direction in general, and such extreme levelsof stacking, in particular, has introduced additional
challenges to the process used to make these memory
chips. Specifically, the high aspect ratio of featuresthat interconnect each of the storage nodes in thedevice requires materials with unique process capabilities. A particular challenge solved by Entegris patentpending technology is the selective removal of silicon
nitride films in a tall SiN/SiO stack in a process used toform the channels where the conductive word-line
metal will be deposited. This process requires that theamount of material removed at the top of the stack be
the same as that at the bottom, and defects resulting
from residuals in the etching process be minimized(Figure 8). Any process selected for this critical stepin the 3D NAND build must demonstrate extreme

Entegris, Inc. | Scientific Report 2021

selectivity, low defectivity, and uniformity across thearray placing stringent requirements on the behaviorof the etch formulation as well as any filtration used
to eliminate defects. Advanced chemistries developed
for this process typically consist of a complex mixture ofadditives in a base etching solution. In addition, advanced
filters useful for removing small defects typically consistof polymeric membranes that have been chemicallymodified to functionalize the surface for the removalof targeted defects. Entegris has patented technology
surrounding the functionalization of polymer mebranes.
However, a complex chemical formulation in the presence of a chemically modified polymer membranerequires a deep understanding of the interplay between
filter and formulation. Without this, the membrane
could remove critical additives in the formulation,
rendering it less effective. Equally problematic is if theetch formulation attacks the functionalization on themembrane, creating a source of defectivity. The mostsuccessful selective etch formulations used in the
fabrication of advanced 3D NAND chips found inadvanced smartphone platforms consist of carefullyengineered chemistries with filter membranes thathave been specifically developed to work with them;that is, a complete formulation/filtration system isrequired to fabricate these advanced devices.

ONO stackPoly-Si channel

SiO2

Metal
gate
SiO2

Figure 8.

11Advancements in Radio
Frequency (RF) Technology

To accelerate the development of complex chemicalsystems like those used in the 3D NAND application,
computational techniques are increasingly used toprovide additional insight. One such model simulates
the behavior of complicated chemical formulations
within nanoconfined spaces such as narrow etchedchannels or the pores of a polymer filter membrane.
Such models reveal that differences in the diffusion rateof components along various directions of a confined
space result in changes in their relative concentration
at different positions in the structure. It also showsthat the composition of the formulation in a confined
space is quite different from that in the bulk solution(Figure 9). This unexpected insight accelerates the rateof learning and allows the formulation to be tuned forthe specific application.

As wireless technology advanced, RF ICs also evolved
to handle increasing speed and power needs. This isparticularly true in the most recent transition from
4G to 5G technology, and research for 6G has alreadystarted. Table 1 lists the evolution of wireless technology in terms of operating frequency and download
speed. It is clear that higher frequency bands areneeded as the industry moves from one generation
to the next to improve transmission speed. For 5G,
the industry will eventually move to microwave
frequencies of up to 100 GHz to achieve gigabyte
per second download speeds.4
For RF ICs to handle the demands of the cellular
network, operating frequency and power range are
two critical parameters that determine the type ofdevices that can be used. While the migration of RF
technology to higher frequencies has been slow inthe past due to the capability of silicon-based MOS
devices, 5G becomes a trigger for the adoption of wideband-gap RF devices such as gallium nitride (GaN) on
Silicon or GaN on SiC substrates. The reason for thissignificant change in device material is the need formuch higher operating power and frequency of 5G
technology. Figure 10 shows the various categories
of RF devices based on their operating power andfrequency window. This chart shows that while Silicon
LDMOS (laterally diffused MOSFETS) can handle highpower RF transmission up to 1 GHz microwave frequency, to achieve true 5G performance of 25 – 100 GHz
while handling increasing power demands requires GaN
devices, either on a silicon substrate for low power
region, or GaN on SiC in both the high power andhigh frequency regimes.

Nano Trench ModelN

XYFormulation in the Nano Trench
Formulation

1.0

A
C
D
E
G
H2O2
H2O

0.8
0.6
0.4
0.2
0
11.34

20

30

40

50

60

70

Z (A)

Figure 9. New modeling approaches are increasingly used in developing
advanced semiconductor chemicals in today's leading-edge nodes.

5G
1G

2G

3G

4G

Low-bandMid-bandmmWaveFrequency

30 KHz200 KHz1.25 – 5 MHz

20 – 100 MHz

600 – 850 MHz

2.5 – 3.7 GHz

25 – 100 GHz

Download
speed

50 Kbps

250 Kbps

3 Mbps

50 Mbps50 – 250 Mbps

100 – 900 Mbps

1 – 10 Gbps

Table 1. Cellular network technology evolution on operating frequency and download speed.

12

Scientific Report 2021 | Entegris, Inc.

Using Chemistry andAdvanced Materials to
Enable the Future

Comparing Power and Frequency of Different Materials
1000
Silicon
GaN/Sic

Power (W)100

GaN/Si

10
GaAs

1
SiGe

0
0

10

1

100

Frequency (GHz)

Source: Analog Devices

Figure 10.

RF GaN technology is a perfect technology for 5G.
Compared to high-frequency processes such as
gallium arsenide and indium phosphide, GaN devices
output more power. Compared to power processes
such as LDCMOS and silicon carbide (SiC), GaN has
better frequency characteristics. GaN RF devices also
carry several distinctive advantages over other types ofsemiconductor RF ICs in size, power density, thermal
performance, and efficiency. Within GaN devices, GaN/
SiC has better power and frequency performance due
to better thermal conductivity and lattice matchingwith the underlying substrate.5
One of the biggest challenges of making GaN devices
is the difficulty of processing hard GaN materials andif used, the underlying SiC substrate. GaN and SiC
are both much harder than silicon wafers, making
polishing these materials to make substrates for RF
semiconductors the key step in adopting these materials. Entegris’ Specialty Chemicals and Engineered
Materials division is a leader in the design and production of chemical mechanical planarization (CMP)slurries used for polishing ultra-hard materials suchas SiC and GaN. Through careful engineering of theabrasive particle and the additives to the slurry, Entegris’
patented technology can increase polishing rates of
hard materials like GaN and SiC by 50% while minimizing surface roughness and defectivity. Such Entegris
technology is critical in enabling 5G technology formobile devices for the next five to 10 years.

Entegris, Inc. | Scientific Report 2021

Mobile technology, as epitomized by the smartphone,is the most ubiquitous manifestation of advanced semiconductor technology in the hands of the everyday
user. This technology is charged to deliver functions
that test the limit of the most advanced production
facilities ever built, and the most complex chip designs
ever created. Structures that perform the role ofswitching the transistor have been miniaturized todimensions on the order of a strand of DNA, andbillions of these transistors are contained within eachof the roughly 500 chips on a wafer, produced at
the rate of tens of thousands of wafers each month,making the transistor the most produced invention
ever built. All this capability is built on a foundation ofhigh-performance materials; it is the content in yoursmartphone that you can’t even see. It is safe to saythat chemistry and the engineered materials it hasenabled is what makes the advancement of mobile
technologies like the smartphone possible. Entegris
contributes in this environment through high performance materials – capable of being engineered at
atomic scale dimensions – with accompanying technology that ensures the integrity of the material fromthe point where it is manufactured to the point where
it is used on the wafer. Without such materials, noneof the functions behind the touchscreen would work.
References	https://www.semantics3.com/blog/evolution-of-the-mobilephone-industry-2/

1	https://www.pcmag.com/news/what-is-the-apple-m1-chip2	https://semiengineering.com/3d-nand-race-faces-huge-tech-and-cost-challenges/

3	https://semiengineering.com/gan-versus-silicon-for-5g/

4	https://www.microwavejournal.com/articles/34896-gan-andgaas-5g-brings-thriving-business-opportunities

5	Used with permission – C. Auth et al., "A 22nm high performanceand low-power CMOS technology featuring fully-depleted tri-gatetransistors, self-aligned contacts and high density MIM capacitors,"
2012 Symposium on VLSI Technology (VLSIT), 2012, pp. 131-132,
doi: 10.1109/VLSIT.2012.6242496.

*

13

ADVANCINGAUTONOMOUSELECTRIC VEHICLES
Smart Materials andDetailed Unit Process
Design Become
Key Drivers
Authors: Jennifer Braggin
Mark Puttock, Ph.D.

Back to the Future
An increasing number of car manufacturers are pursuing two
new technologies in parallel – fully electric and autonomousvehicles. In doing so they are introducing consumers to an
exciting new future. That future holds the promise of newmodes of transportation that directly address climate change,
equity, and safety.
Introducing these new technologies in parallel presents anincredible opportunity for the semiconductor industry. For
electric vehicles, the materials landscape is very broad. Wideband gap devices are at the heart of electric and hybrid vehicles
being used for power distribution, vehicle charging, high intensity
headlights, and light detection and ranging (LIDAR). For autonomous vehicles, silicon-based semiconductor technologies arebeing utilized in an increasing number of applications in thecar, and the designs of these devices are pushed to their limits.
Silicon-based technologies are used in powertrain, networking,infotainment, communications (5G), and most importantly,
safety systems. As more complex devices designed for artificial
intelligence (AI) are integrated into safety systems, there ismuch more opportunity for innovation and risk.
Semiconductors Power Today’s Automobiles
Networking

Infotainment

Power Train

� CAN
� LIN
� MOST� Bluetooth� Dashboard
� Entertainment
� ITS/GPS� Engine control
� HEV/EV motor� Transmission

Electronic System
� Alternator, battery,and starter� Lighting� Diagnostics

Safety and Control

Comfort and Control

Chassis� Airbag� Collision warning� Parking assistant� Back monitor

� Power doors/windows� Climate control
� Seat controls

� Steering/EPS
� Brakes/ABS
� Suspension

Figure 1. Semiconductor content in modern automobiles.

15

Concerns regarding these new technologies comefrom the different expectations and requirements
placed on automotive electronics when compared
to consumer electronics (Table 1). Most people only
expect their mobile phone to last a few years, whereas
they expect their car to operate for 10 – 15 years.
These high expectations and requirements mandate
a fundamental change in how automotive electronics
are designed for functional safety. Functional safety,
as defined by ISO 26262, means that autonomous
cars perform their tasks exactly when the tasks aresupposed to be performed. In most cases, however,the devices that power these tasks may have latent
defects which, over the life of the devices, mayinterfere with normal operation.
To build an understanding of functional safety startingwith the manufacture of semiconductor devices, theAutomotive Electronics Council (AEC) recently updated
a version of the Automotive Zero Defects Framework
AEC-Q004.1 This document identifies opportunities
for members of the semiconductor supply chain toachieve the “zero defect strategy,” which targets zero
system-level failures. Areas of interest in the document
provide the best practices in manufacturing, test,

reliability, and continuous improvement methods.
However, the document does not go so far as to prescribe how to apply these best practices and ultimately
falls short of giving the members of the supply chain
useful guidelines to achieve zero system-level failures.
This topic was recently addressed by Volkswagen in apaper at the International Integrated Reliability Workshop, highlighting the need for collaboration acrossthe semiconductor and automotive supply chains to
identify opportunities for improvements specificallyfocused on contamination control.2
Another source of concern is introduced as semiconductor manufacturers rapidly introduce new materials
into the chip fabrication process to accommodate
new technologies long before ramping to full yieldand monitoring reliability becomes an issue. Figure 2
highlights the number of new materials introduced
over time. Those in the newest classification (in lightgray) include several materials that have yet to go
into mass production but are being investigated.
With the rapid demand for new materials, Entegris is
poised to be able to provide innovative solutions toenable a more electrified, automated driving experience.

Rh, Ir, Mo, MoS (2D),Graphene, CNT, V,
NiAl, IGZO, Yttrium,
Metal mix Ru/Co/Mo,
HfO(Zr) memory
La (HKMG), Cu reflow,
aC HM (B doped),sSOI/GeOI, III-V IL, Ge
IL, Ge, InGaAs, InSb,
GaN, STO, Ru

La (HKMG), Cu reflow,
aC HM (B doped),sSOI/GeOI, III-V IL,
Ge IL, Ge, InGaAs,
InSb, GaN, STO, Ru

Metal oxides (memory),
GST, CuMn, Co, Air,
SiC, LT SiO, LaO, SiCO

Metal oxides (memory),
GST, EUV PR, Co, Air,
SiC, LT SiO, LaO, SiCO

Metal oxides (memory),
GST, EUV MO PR. SnO,
Co, Air, SiC, LT SiO,
LaO, SiCO

SiCN, TiAlC MG, AlO,
Hf(Si)O, ZrO, pSiOC,
SOI, SiGe(B)

SiCN, TiAlC MG, AlO,
Hf(Si)O, ZrO, pSiOC,
SOI, SiGe(B)

SiCN, TiAlC MG, AlO,
Hf(Si)O, ZrO, pSiOC,
SOI, SiGe(B)

SiCN, TiAlC MG, AlO,
Hf(Si)O, ZrO, pSiOC,
SOI, SiGe(B)

SOG, TaO, SiOC, Ta/
TaN, Cu SiOF, TiSi,
PtSi, ITO, WSi, W, TiW,
TiN, P, B, Ge dopants,
Al, BPSG, SiO, SiN,
resist, Si

SOG, TaO, SiOC, Ta/
TaN, Cu SiOF, TiSi,
PtSi, ITO, WSi, W, TiW,
TiN, P, B, Ge dopants,
Al, BPSG, SiO, SiN,
resist, Si

SOG, TaO, SiOC, Ta/
TaN, Cu SiOF, TiSi,
PtSi, ITO, WSi, W, TiW,
TiN, P, B, Ge dopants,
Al, BPSG, SiO, SiN,
resist, Si

SOG, TaO, SiOC, Ta/
TaN, Cu SiOF, TiSi,
PtSi, ITO, WSi, W, TiW,
TiN, P, B, Ge dopants,
Al, BPSG, SiO, SiN,
resist, Si

SOG, TaO, SiOC, Ta/
TaN, Cu SiOF, TiSi,
PtSi, ITO, WSi, W, TiW,
TiN, P, B, Ge dopants,
Al, BPSG, SiO, SiN,
resist, Si

2000

2010

2015

2020

2025 Potential

Figure 2. The rapid increase of materials used in semiconductor manufacturing.
16

Scientific Report 2021 | Entegris, Inc.

Automotive IC Requirements Versus Mobile
AUTOMOTIVEMOBILE

Process>180 nm – 7 nm

>28 nm – 7 nm

Frequencies>30 MHz – 5.9 GHz>900 MHz – 2.7 GHz

Voltages-1 V – >60 V

0.5 V – 1.8 V

Temperatures-40 – 155°C

0 – 40°C

Operation lifetime

10 – 15 years

1 – 3 years

Target field failure rates

Target zero failure<10%

Table 1. Source: Synopsys, Deloitte analysis.

Designing Materials
for Power Devices
Wide band gap devices are very attractive to the automotive market. SiC devices have reduced power loss,
high speed switching operation, the ability to operate
at high temperatures, and improved heat-dissipation
techniques over standard Si devices (Figure 3). GaN
devices are desirable to the automotive industry because
they have small on-state resistance, very low conduction
loss, fast switching speed, and high electron mobility.
These factors allow SiC and GaN devices to be smaller,
which saves space and reduces the need for heatsinks, conserving total power.
SiliconSilicon Carbide

MOSFET Structure
Gate

Sourcep

MOSFET Structure

n+

n

–

Gate

SourceSource
n+

p

p

n+

n

–

Sourcen+p

SiC substrate
Drain electrodeSi substrate
Drain electrodeSignificant
reductionin electricalresistance

Figure 3. A comparison of the footprint of the same inverters using
Si and SiC technologies.

These performance benefits come from the inherent
material properties of SiC or GaN, which can be difficult
to produce at large scale, and today are generally manufactured at substrate sizes of 200 mm and below.
Because these devices have not been produced in
Entegris, Inc. | Scientific Report 2021

nearly the high volumes of standard silicon devices,
nor have they been on the market for very long, it
is difficult to understand how reliable they will be.3
Focusing early on smart materials design, particularly
the SiC and GaN materials, can be one way to build
in long-term materials reliability.
Physical vapor transport (PVT) is one method for
growing SiC crystals as boules. In this method, SiC
powders are applied to a seed material and are heated
above 2,000°C within a graphite crucible. The purityof the resulting substrate is highly dependent on thepurity of the SiC powder and the cleanliness of thegraphite crucible. SiC wafers can also be produced
using high temperature chemical vapor deposition(HT CVD), whereby precursor materials, such as SiH4
and hydrocarbon gases, are fed into a chamber attemperatures above 2,000°C. The crystal slowly grows,
similar to an epitaxial process. What most impacts the
success of this process is the ability to have precise,pure gas supply and temperature control within thechamber. Entegris produces gas delivery systems withimproved safety functionalities that aid in this process.
GaN substrates can be made using different methods.
In hydride vapor phase epitaxy (HVPE), GaN is grownby a reaction between GaCl and NH3. This is the primarymethod of making GaN substrates. GaN substrates canalso be made using a hetero-epitaxial growth method
where the GaN layers are grown on sapphire, diamond,
SiC, AlN, or Si substrates. Growing GaN on SiC or Si
reduces production costs. GaN substrate manufacturers can benefit from many of the Entegris technologies
already mentioned, as they are similar for this process.
17

Once the substrate has been sawed into individual
wafers, it is ground down at the edges and polishedinto a flat, uniform substrate. The polishing step inparticular is very important. SiC substrates polish at
8 – 10x lower rate of standard Si substrates. Therefore,
careful design of the slurry materials for polishing isrequired. Entegris’ slurry business is a market leader inthe design and production of chemical mechanicalplanarization (CMP) slurries for polishing ultra-hardsurface materials such as SiC and GaN into epitaxial-ready condition. The materials designed for theseprocesses require that specialized chemistry andengineered particles be combined to soften hardsurfaces, increase removal rates, decrease abrasive
mechanical action, and remove surface defects.
What makes polishing these substrates so difficult
is that the wide bandgap materials are not just hard,
but they are also chemically inert. This results in poor
chemical-mechanical action during polishing. In
addition, the hard particles traditionally used for silicon
device polishing steps cause significant surface and subsurface damage on these substrates, and soft particles
result in very slow polish rates and long polishing times.
Therefore, the design of the slurry must be very
deliberate. Entegris combines a unique suite ofsurface-engineered particles (Figure 4) with proprietary chemicals to achieve enhanced removal rate,surface finish, and defectivity.
Reactive CMP (RCMP)Engineered
particle

Localized
reactionzone

Where materials design will have a significant impact on
power devices for the electrification of transportation,
so will it have a significant impact on vehicle autonomy.
More AI specific designs, including graphics processing
units (GPUs), field-programmable gate arrays (FPGAs),and application-specific integrated circuits (ASICs), arebeing developed because they are significantly more
efficient and faster than today’s designs for training
and inference for AI specific algorithms (Figure 5). As aresult, these chips are more energy efficient and costeffective in complex systems that are required forhighly parallel computations required of autonomousvehicles.4
CPU vs. GPU Chips

Soft
particle

Mechanically hard substrate

Figure 4. Innovative abrasives used in the design of slurries for widebandgap materials.

The creation of wide bandgap devices can also benefit
from several Entegris technologies. Much like withstandard Si devices, several epitaxy, deposition, andetch processes are required. Entegris’ Specialty Gas
business creates pure, safe GaCl (+NH3) and AlCl3
gases for epitaxial growth. Entegris also creates plasma
enhanced chemical vapor deposition (PECVD) materials, such as oxides and nitrides, which are critical for18

Anticipating Autonomy Risks
with Materials Design for
Sub-N7 Designs

Nanodiamond CMP (NCMP)+chemistry

Chemically inert substratepassivation layers. Ensuring the materials are pure anddelivered safely is the first step in reducing reliability
risk for devices in the field.

CENTRAL PROCESSING
UNIT (CPU)GRAPHICS PROCESSING
UNIT (GPU)• Multiple cores• Optimized for singletasks• 3 orders of magnitude
more cores than a
CPU• General purpose
computing• Optimized for many
concurrent tasks• Slow to build and trainmodels for machinelearning (ML)• Optimization of
specialized computing• Low compute density• Fast to build andtrain models for ML(machine learning)• High compute density

Figure 5. Comparing a central processing unit (CPU) with a GPU,
whereby GPUs are being leveraged for AI applications.

Scientific Report 2021 | Entegris, Inc.

With new applications will come a host of novel
materials required for manufacturing (Figure 3) that
could introduce new challenges. One process that is
extensively used in both advanced Si and GaN device
manufacturing is atomic layer deposition (ALD). ALD
provides atomic level control of deposition. For GaN
devices, ALD is used to create gate dielectric materials. Entegris has been working with semiconductor
manufacturers for years to deliver clean ALD sourcesthat can enable these new technologies.
In addition, there will be many new materials introduced,
which means there will be a need for tailored chemistries for cleaning. Entegris’ chemists have expertisein formulating selective wet etching chemistries forcleaning applications as they evolve with each newtechnology node.
Another materials change facing Si devices will be themetallization layers. As feature sizes shrink, metal line
resistivity increases dramatically as copper grain sizes
become as wide as the patterns themselves. In addition,
as the lines narrow, the proportion of liner and barriermaterials increases, which also increases resistivity.
Therefore, new metallurgies are being implemented
and explored to continue shrinking Si devices. Thismeans transitioning from tungsten (W) and copper(Cu) to cobalt (Co), molybdenum (Mo), and ruthenium(Ru). These transitions require several process changes
in addition to the material changes. Entegris has beena pioneer in creating precursors for the materials thatenable these new metallurgies.
Changing the metal is one step in transforming theprocess. Cleaning the surface after the CMP process
is also critical and requires specialized chemistries.
Entegris has developed formulations for use with Co,
whereby etchants dissolve Co oxides and organic
additives remove organic residues remaining fromthe process. Corrosion inhibitors are also added tocontrol galvanic corrosion during cleaning.

Summary
By addressing the opportunities presented by the new
AEC-Q004 Automotive Zero Defects Framework, carmanufacturers are moving to drive semiconductor
manufacturers to identify areas for improvement thatwill address yield and long-term reliability. These are
more important now than ever as SiC, GaN, and Artificial
Intelligence devices are concurrently being introduced
into the automotive supply chain. As semiconductor
manufacturers work to push the limits of their ability tointroduce new materials and new processes into theirfactories, it will be difficult to ramp yield and improvereliability without the support of the automotive systemdesigners and suppliers in both industries.
A holistic approach to designing and implementing
smart materials begins by having all interested parties
engaged in solving the problems that directly impact
yield and reliability. And this is just one piece of the
puzzle. Engaging the entire supply chain in discussions around materials, contamination control, andmaterials handling will accelerate the speed at whichissues get addressed. Ensuring that automotive manufacturers, suppliers, and semiconductor manufacturers
have close communication and a thorough understanding of the challenges is just the first step. Entegris
participates in these collaborations and will continue
to design and deliver innovative materials, contamination control, and materials handling solutions toenable our automated and electrified future.
References
	AEC-Q004, Automotive Zero Defects Framework, Automotive
Electronics Council, 26 February (2020); http://www.aecouncil.
com/Documents/AEC_Q004_Rev-.pdf.

1	Aal, A., Braggin, J., Amade, A., and Puttock, M., Addressing weak links
in automotive reliability – semiconductor contamination control,
inspection, and test, IEEE International Integrated Reliability
Workshop, (2020).

2

	Lapedus, M., Improving Reliability for GaN and SiC, Semiconductor
Engineering, 18 June (2020); https://semiengineering.com/
improving-reliability-for-gan-and-sic/.

3	Khan, S.M, Mann, A., AI Chips: What they are and why they matter,
Center for Security and Emerging Technology, (2020); https://cset.
georgetown.edu/publication/ai-chips-what-they-are-and-whythey-matter/.

4

Entegris, Inc. | Scientific Report 2021

19

FROM
PROTOTYPESTO HIGH VOLUMEMANUFACTURING
Entegris' AM Journey
Authors: Montray C. Leavy, Ph.D.
Subhash Guddati

An Innovative Approach to Next
Generation Product Development
Remaining competitive in the era of Industry 4.0 requires
businesses to look at new ways to offer superior products andsolutions at attractive prices (Figure 1). To achieve this goal,industries are keen to innovate and make fundamental changes
to the way they design and fabricate products. One such innovation is additive manufacturing (AM) also known as 3D printing.
AM offers several advantages to traditional manufacturing
including freedom of design, waste and inventory reduction,ease of manufacturing complex geometries, reduced productdevelopment cycle times, and on-demand production ofcustom parts. It also enables the transformation from conventional centralized production to a customized, networked,
distributed production system. For example, the U.S. Navy is
exploring the use of shipboard AM to increase self-sufficiency
by fabricating replacement parts on-demand thereby reducing
the need to carry a heavy inventory of assorted hardware atsea.1 In short, AM is a game changer for the manufacturingsector. This article covers the basics of 3D printing, the roleof modeling and simulation in AM, and how Entegris has
adopted AM into its new product development process.
As defined by ASTM international (ASTM 2792-12), additive
manufacturing is a process of joining materials to make parts
from computer-aided design (CAD) models, usually layer uponlayer, as opposed to material removal methods like machiningor milling.2 3D printing technologies are broken into sevencategories based on the material and the method by which
it is applied (Table 1).
Advantages of 3D Printing

Faster Speed to Market

Quality Improvements

1. Customization
2. Innovation (development)

1. Reliability
2. Conformance

Increased Design Flexibility

Lower Cost

1. Volume flexibility
2. Product variety

1. Less waste
2. Low productdevelopment cost

Figure 1.
21Summary of Existing 3D Printing Processes
PROCESS TYPE

PROCESS DEFINITION

MATERIAL

BENEFITS

LIMITATION

Material extrusion

Material in filament
form is extruded
through a nozzle
where it is heated
and deposited layer
by layer to form thepart.

Polymer• Capital and operation
cost is low• Layer lines are visible
and affect the surface
finishDroplets ofbuild material
are selectively
deposited andsolidified layer
by layer.

Photopolymer

A liquid binding
agent is selectively
deposited to join
powder materials
layer by layer.

Metal

Sheets of material
are bonded to form
an object by stacking
layer by layer.

Hybrids

Generates parts byselectively curing aliquid photopolymer
resin layer by layerusing light.

Filament
extruded
from nozzle

Material jettingMaterial
jetting
UV
curingBinder jetting
PowderhopperBinderUV
curingRoller

MetalsCeramics

Wax

Polymer
Ceramic

Powderbed

Sheet lamination
Laser cutting
RollerVat photopolymerization
UV
curingLaser source
RecoaterPowderbed

Directed energy
deposition
Laser source
Powdersupply• Printhead clogging
and warpage forlarger prints• Only limited materials
can be printed• Achieve outstanding
accuracy and surface
finishes• Printed parts are
structurally weak andare not suitable forfunctional applications• Printed parts havehomogeneous
mechanical andthermal properties• Wide range of materials
such as metals, polymers,
and ceramics can be
printed• Less accurate due toshrinkage of part
• Not currently able toprint high density parts• No deformation of parts
as no thermal process isinvolved during printing• Process can print
bimetallic or multimaterial components• Hollow or parts withinternal features arechallenging to produce

Ceramic• Faster print time but
requires post processing
to achieve the final shapeand size• Generates morematerial waste whencompared to other
AM methods

Photopolymer• Good accuracy andhigh surface finish• Limited to photo resinsmaterial only

• Process can print metals
and ceramics by mixing
with photopolymer
resins• Lack of strength anddurability of theprinted parts• Powder recycling isfeasible with proper
control• Thermal distortion andwarping issues due to
use of high thermalenergy for printing

Metal

Ceramics

Liquid resin

Powder bed fusion• Process can print metals
and ceramics by binding
with polymers andextruding into filament

Part is formed by
selectively melting
or fusing successive
layers of powderusing thermalenergy.

Metal

Focused thermalenergy is used tofuse materials by
melting as they arebeing deposited.
The feedstock can
be in powder orwire form.

Metal

Polymer• Process can printfunctional critical parts
with high density andsurface quality• Capability to build
larger parts• Suitable for repair orreconditioning of an
existing part• Still affected by UV light• Powder cost is very
high and without
recycling the powder
it will be an expensive
process• Printing resolution is
low which results inpoorer surface finish
and requires secondary
processing• Not suitable to print
overhang or conformallycooled channel parts as
support structures can’t
be used for printing

Source: Synopsys, Detroit analysis
22

Scientific Report 2021 | Entegris, Inc.

3D Printing Process Flow

Laser source
RecoaterPowderbed

Cad model

STL file

Added support
structures

Defined slicing andprocess parameter

3D printing

Final productFigure 2. Typical process flow in 3D printing.

3D Printing at Entegris
In recent years, Entegris has been using 3D printing
technology for polymer-based materials to produce
protypes, jigs, and fixtures to support the developmentof new product designs. 3D printing not only provides
an alternative to conventional manufacturing by beinga cost-effective substitute for low volume high mix
products, but also has accelerated product development cycles by enabling rapid prototyping required
for functional testing of critical designs.
Beyond polymer-based materials, Entegris also has
active development programs, some of which arepatent pending, in porous metals, ceramics, andadvanced materials like zeolites and metal-organic
frameworks (MOFs). Each of these materials has its
own challenges in the design and process phasesof development: customized designs that consist ofcomplex shapes, buried structures such as conformal
cooling channels, and materials of construction thatcannot be processed with conventional fabrication
techniques. In addition, Entegris has fabricated parts
with specific density and gradient porosity that can
only be achieved with 3D printing.
Generally, 3D printed parts require several post processing operations like de-powdering, machining, heat
treatment, and polishing to obtain the required surface
finish. Figure 3 illustrates 3D printed parts before andafter going through various post-printing processes.

Entegris, Inc. | Scientific Report 2021

As printed condition

After post processing

Figure 3. Parts before and after finishing processes.

23Role of Modeling and
Simulation in 3D Printing
Typically, finite element modeling (FEM) and computational fluid dynamics (CFD) simulations are used in
the design phase of product development to evaluate
a product’s performance and functionality. Recent
advances in 3D printing-specific simulation software
now make it possible to visualize complex thermomechanical phenomena during printing. Results fromthese simulations can be used to predict distortion,
stress, microstructural characteristics, and thermal
strain. Entegris is integrating these simulation tools into
its product development processes to overcome thecurrent challenges and restrictions associated withconventional manufacturing and various aspects of
3D printing processes (Figure 4). Specifically, we haveused modeling to evaluate the printability of complex
designs, the flow of material in a printer’s powder bed,
and the heat flow and distortion of a part during its
fabrication.

Fully Leverage
the Advantages
To fully leverage the advantages that AM offers
in producing complex geometries and reducing
component weight while maintaining structural
integrity, design for additive manufacturing (DFAM)
is often employed. DFAM3 methods take advantageof the enormous design freedom this technology
provides and can be employed to leverage multiscale
structures for weight reduction, topology optimization,and part consolidation. Figure 5 illustrates an example
of topology optimization where the mass of an existing
component is reduced by 47% resulting in a lighter
weight, more cost-effective component with superior
thermal performance in the high temperatureenvironment where it is used.

24

Design simultion

Powder bed flow simultion

SLM process simulation

Figure 4. Modeling and simulations.

Scientific Report 2021 | Entegris, Inc.

Original Design

Lattice Design

Topology Optimization

Mass: 114.23 g

Mass: 85.3 g

Mass: 60.4 g

(25%

)

(47%

)

Figure 5. Topology optimization.

Entegris Collaborates in
the Additive Manufacturing
Ecosystem
To fully leverage the benefits and determine theoptimal way to incorporate AM into our technology
ecosystem, Entegris is strategically collaborating withkey universities and research institutes. We recently
launched a joint research laboratory with the Agency for
Science, Technology, and Research’s (A*STAR) Singapore Institute of Manufacturing Technology (SIMTech)
dedicated to the development and enhancement ofEntegris products leveraging additive manufacturing
technologies coupled with state-of-the-art modelingand simulation techniques. Activities of this joint development focus on metal and ceramic component
development, the redesign of novel metal-based
products, and the characterization of various metal
powders. Such research is intended to identify ways toovercome the current design constraints in traditional
manufacturing and lead to innovations in 3D printingthat benefit a wide range of applications in thesemiconductor, aerospace, medical, and energy
industries.

Entegris, Inc. | Scientific Report 2021

References	https://www.navsea.navy.mil/Media/News/SavedNewsModule/
Article/2366654/nswc-philadelphia-division-supports-additivemanufacturing-in-the-fleet/1	https://www.astm.org/industry/additive-manufacturing-overview.
html#:~:text=Additive%20Manufacturing%20Standards%20
Drive%20Innovation,piece%20of%20material%2C%20often%20
metal

2

	https://en.wikipedia.org/wiki/Design_for_additive_manufacturing

325

STATE-OF-THE-ART
SPACE OPTICS
Innovative Materials for a
Challenging Environment
Authors: Wayne Hambek
Troy Scoggins, Ph.D.

Optics in SpaceThe standard for astronomical space imaging was set with the1990 launch of the Hubble Space Telescope. Since its famous
optical correction in 1993, scientists have used Hubble’s 2.4 m
telescope to gather images from distances up to 13.4 billion lightyears1 and have contributed data to more than 13,000 journal
articles,2 making Hubble one of the most productive science
missions ever launched. In October 2021, the telescope is set
to be supplanted by the NASA/ESA/CSA James Webb mission.
Webb’s 6.5 m primary mirror will collect images across a wide
EM spectrum, and its ability to gather exponentially more
light will lead to ever greater discoveries.
While astronomical missions have provided insight to fundamental physics, of growing global concern is atmosphericpollution that causes a variety of negative health conditions
in both developed and developing nations. The World HealthOrganization (WHO) estimates that in 2016, 91% of the world’s
population lived in areas where air quality guideline levels were
not met, and outdoor air pollution caused 4.2 million premature
deaths each year, most in developing countries.3 Consequently,
remote sensing is an important tool that government agencies
use for assessing the effectiveness of policies designed to reduce
air pollution. Space-based optical systems are ideal for monitoring air pollution and environmental quality on a global scale.
Commercial applications of earth imaging are also growing,along with the number of companies supplying those images.
Google Maps, Apple Maps, and Life360 are familiar consumer
applications enabled by satellite imaging. Companies providing
the imaging also support commercial farming, energy, mining,finance, and information businesses.
Finally, communication is a growing application of space-based
optics. A new breed of companies are developing launch capability and satellite networks to support the growing demand for
low-latency internet. To support gigabit data capacity at low
power, communication between satellites is planned to beenabled through high-frequency lasers, and receivers of thoselasers will require optical collectors.4 Several companies areworking to economically manufacture thousands of telescopes
to optical standards that can withstand the low earth orbit(LEO) environment.

27

Each of the missions listed above is optimally located in
one of a handful of orbits. These orbits present different
environmental challenges to reliable operation. Objects
in LEO experience high velocity travel through a thin
atmosphere, and multiple cycles through sunlight anddarkness per day. In geostationary equatorial orbit (GEO),
satellites are further from Earth and synchronized with
its rotation, and therefore see only one sun cycle perday. However, these satellites are exposed to higher
radiation. Polar orbits exist at altitudes between LEO
and GEO and travel roughly from north to south. The
trade-off between mission performance, reliability,
and cost, determine where to locate a satellite orconstellation, and these factors impact the choiceof materials to be used.

Space-Based Optics Materials
Two figures of merit define the trade space when
considering material choices in the design of optics.
For scanning systems, the mechanical figure of meritE/ρ (elastic modulus by density, or specific stiffness)determines how rapidly mirrors can be accelerated,decelerated, and fixed for imaging. In systems that see
thermal cycles, thermal diffusivity/CTE expresses how
much deformation will be induced in an instrument
during solar transits.

Historically, instrument designers began with readily
available materials such as carbon fiber, titanium, steel,aluminum, and glass which could be easily fashioned
into appropriate shapes, then add design complexity
to compensate for limitations in material properties
and manufacturing capabilities. These compensation
schemes were necessary when systems were composed of different materials, and typically took theform of flexures and alignment options. These added
features drove up integration costs and lengthened
assembly cycles.
Low-volume, high-performance instruments like
Hubble and James Webb demand perfect design
and flexible fabrication and assembly, driving up costand delaying the fabrication schedule. As the market
for space optical instrumentation grows, standardization and high-volume manufacturing are generating
innovation, leading to quality improvements at reduced
cost. Optics integrators are interested in designinghigh-volume instruments using monolithic material
systems for optimal performance combined with“snap-together” interchangeable components to
reduce integration cost.

Figure of Merit Comparison
100
CVD SiC

Entegris SUPERSiC-Si

90

Thermal Figure of Merit (k/α)

80
Silicone Single Crystal

70

Entegris SUPERSiC

60

C/SiC

Reaction Bonded SiC

SiCp/CVD SiC

NT SiCHot Pressed SiC

CESIC

50
40
Silicon, CVD

30

UltraSic

ZERODUR EC 1

Be I-70H

6061 Aluminum

20
Invar 39 39% Ni

10Be AlBeMET 162

SXA SiCp/Al
BK-7 glass

0
0

20

40

60

80

100

120

140

160

180

Mechanical Figure of Merit (E/p)

Figure 1. Figures of merit for satellite materials.

28

Scientific Report 2021 | Entegris, Inc.

Surveying the material landscape to support theseemerging requirements, silicon carbide (SiC) stands
out as the leading candidate. For decades, SiC has
been promoted for its outstanding performance,5, 6, 7, 8
but limitations in manufacturability have kept costs
high. Various forms of SiC have been evaluated foruse in space optical systems, including powder
forming, green sintering, chemical vapor deposition,and chemical vapor conversion processes.5 Powderbased processes include slip casting of SiC slurries,
sintered SiC pre-forms and cold isostatic pressing of
SiC powder. Each technology entails shaping and thensintering to form the final silicon carbide article. Finishedsubstrates made using these technologies have highdensity and strength, but their performance is limited
by up to 20% sintering shrinkage, large minimum crosssection, and draft angle requirements. Chemical vapor
deposition results in a very strong, high density, highly
polishable material with excellent properties, but withhigh cost and limited design flexibility. The Entegris
chemical vapor conversion process involves producing
a special form of graphite designed specifically forconversion, and machining that graphite into lightweight shapes needed for optical structures. This
process produces net-shaped, complex components

at low cost because machining is performed in thegraphite state. Mature joining technologies enable
even greater shape-making capability and performance. This combination provides a cost-effective
path to monolithic system architecture and ideal
thermal matching, minimizing image distortion in
any thermal environment.
While bulk mechanical stability is important, the critical
optical surface also requires fidelity to figure down tofractions of the wavelength of light to achieve image
quality and high resolution. To realize a reflective surface,a fully dense material must be applied to the mirror
substrate. The combination of a porous or densified
silicon carbide with a fully dense polycrystalline
CVD SiC coating provides a substrate which canbe optically polished, with a near perfectly matched
thermal expansion coefficient. CVD SiC surfaces havebeen successfully polished to λ/50 (λ=632 nm) figure
error,9 yielding excellent image quality over a wide
temperature range.10

Optics Materials

MATERIALDENSITY (ρ)

ELASTICMODULUS(E)

THERMAL
EXPANSION@ CA 293K (α)

THERMALCONDUCTIVITY(κ)

MECHANICAL
FoM
(E/ρ)

THERMALFoM(κ /α)

Borosilicate 7

2.23 g/cc

63 GPa3.3 × 10-6/K

1.142 W/m•K

28 kN•m/g

0.36

Sintered SiC 11

3.1 – 3.19 g/cc

420 GPa

2.0 × 10-6/K

180 W/m•K

133 kN•m/g

90

CVD SiC

3.21 g/cc

466 GPa

2.2 × 10-6/K

280 W/m•K

142 kN•m/g

65

Reaction
Bonded SiC

2.89 g/cc

391 GPa

2.4 × 10-6/K

155 W/m•K

135 kN•m/g

65

Entegris
SUPERSiC®

2.55 g/cc

248 GPa

2.0 × 10-6/K

158 W/m•K

97 kN•m/g

79

Entegris
SUPERSiC®-Si

3.05 g/cc

330 GPa

2.3 × 10-6/K

204 W/m•K

110 kN•m/g

88

Beryllium

1.85 g/cc

287 GPa11.3 × 10-6/K

190 W/m•K

155 kN•m/g

17

Zerodur® 12

2.53 g/cc

91 GPa-0.09 × 10-6/K

1.64 W/m•K

36 kN•m/g

18

Aluminum

2.7 g/cc

68 GPa23.6 × 10-6/K

170 W/m•K

25 kN•m/g

7

Table 1.
Entegris, Inc. | Scientific Report 2021

29

Example Missions
GEOSTATIONARY ENVIRONMENTAL
MONITORING SPECTROMETER

MULTISLIT OPTIMIZED SPECTROMETER (MOS)——Space-based instruments offer an unparalleledtechnology for global scale environmental monitoring.
The United States, Republic of Korea, and the European
Union are developing a constellation of satellites aimed
at monitoring atmospheric pollutants; the Tropospheric Emissions: Monitoring of Pollution (TEMPO), theGeostationary Environment Monitoring Spectrometer(GEMS), and the Sentinel 4 (S4), respectively. Ball
Aerospace developed both the TEMPO and GEMS as“co-development” satellites. These instruments will
be deployed over the United States, and much of
Asia and Europe to monitor several species including
nitrogen and sulfur oxides, ozone and light aldehydes,
and atmospheric aerosols.13
The National Institute of Environmental Research,
Republic of Korea launched the GEMS onboard theGK-2B satellite in late 2019. This spectrometer operates
in the 300-500 nm range with spectral resolution of
0.2 nm.6 Entegris SUPERSiC® lies at the heart of the
fully deployed and operational GEMS and TEMPO
satellite spectrometers as the primary collectors.

A second proposed mission which incorporates SUPERSiC® material technology takes even greater advantageof the benefits of silicon carbide, being composed ofmultiple mirrors and a full structure bonded and assembled from silicon infiltrated SUPERSiC-Si. The NASA/
Ball Aerospace Multislit Optimized Spectrometer (MOS)
is a hyperspectral multiplexing instrument designed
to remotely monitor coastal areas multiple times per
day from a GEO orbit, while providing high resolution
imagery in a challenging signal-to-noise ratio environment. The instrument was manufactured as a bench
combined with six walls, all formed from Entegris
SUPERSiC-Si and bonded into a rigid, lightweight
structure with mounts and windows to accommodate
instrumentation. The highly efficient architecture combines multiple slits into a single instrument, reducing therequired aperture, volume, and weight to achieve themission. Structural, thermal, and optical performance(STOP) analysis of the instrument successfully demonstrated excellent thermal stability. Vibration testing tolaunch loads is expected to move the spectrometersubassembly to a technology readiness level of 6 (TRL6).
Design analysis indicates that the weight of a four-slit
system can be reduced by two thirds when compared
to a single-slit spectrometer. Optimal lightweight design,
combined with world-class thermal stability will enable
this compact instrument to achieve its mission while
being launched as a hosted payload alongside a geostationary communications satellite, greatly reducing
total cost.14
CMA

LEDs

SMA

Figure 2. GEO-KOMPSAT 2B.15

30

Grating

Figure 3. GEMS instrument x-section.6

Focal plane(CCD)

Figure 4. GEMS scan mirror.16

Scientific Report 2021 | Entegris, Inc.

Conclusion
Optical systems in space are becoming increasingly
useful tools across a wide range of applications. As
access to space becomes more affordable, increasing
numbers of environmental, scientific, and commercial
instruments are being envisioned and deployed. The
missions those instruments pursue drive ever-increasing
demands for image quality and economy, while theenvironments they inhabit challenge those demands.
New materials, material combinations, and manufacturing techniques are being developed to meet thosechallenges, with variants of silicon carbide showing great
promise for achieving performance and cost targets.
Early mission successes using Entegris’ SUPERSiC®
portend a bright future for the technology.

	Won Jun Choi, Kyung-Jung Moon, Jongmin Yoon, Ara Cho,
Sang-kyun Kim, Seounghoon Lee, Dai, ho Ko, Jhoon Kim, Myung
Hwan Ahn, Deok-Rae Kim, Sang-Min Kim, Ji-Young Kim, Dennis
Nicks, Jeong-Su Kim, Introducing the geostationary environment
monitoring spectrometer, J. Appl. Remote Sens. 12(4), 044005 (2018).

6

	L. Feinberg et al., Space telescope design considerations,Opt. Eng. 51(1), 011006 (2012).

7

	Fang Jiang, Yan Liu, Yong Yang, Zheng-Ren Huang, Dan Li, Gui-ling
Liu, Xue-Jain Liu; Research Progress of Optical Fabrication and
Surface Microstructure Modification of SiC, Journal of Nanomaterials,
Volume 2012, Article ID 984048.

8	J. Kong and K. Young, Super Polishing of SiC Aspheric Optics, inImaging and Applied Optics Technical Papers, OSA Technical Digest(online) (Optical Society of America, 2012), paper OW1D.3.

9

	Jitendra S. Goela, Michael A. Pickering, Raymond L. Taylor, Brian W.
Murray, and Arthur Lompado, Properties of chemical-vapor-deposited silicon carbide for optics applications in severe environments,
Appl. Opt. 30, 3166-3175 (1991).

10

References	P. Oesch, B Robertson, UCSC; A. Field, Space Telescope Science
Institute; https://www.nasa.gov/feature/goddard/2016/hubbleteam-breaks-cosmic-distance-record.

1	Iman Ghosh; Exploring the Expanse: 30 Years of Hubble Discoveries;
Visual Capitalist, April 24, 2020; https://www.visualcapitalist.com/
30-years-hubble-discoveries.

2

	https://www.who.int/news-room/fact-sheets/detail/ambient(outdoor)-air-quality-and-health.

3	spie.org, Lasers Harken a Data Revolution for Space, Johnson-Groh,
2021; https://spie.org/news/photonics-focus/janfeb-2021/lasersharken-data-revolution-for-space?SSO=1.

4

	John S. Johnson, Kevin D. Grobsky, and Don Bray Rapid fabrication oflightweight silicon-carbide mirrors, Proc. SPIE 4771, Optomechanical
Design and Engineering 2002, (9 September 2002).

	NASA Science: Solar System Exploration; Feb 24, 2009; https://solarsystem.nasa.gov/news/307/galileos-observations-ofthe-moon-jupiter-venus-and-the-sun/.

11

	Zerodur® is a registered trademark of Schott Glass Co.

12	33rd Space Symposium, Technical Track, Colorado Springs,
Colorado, United States of America Presented on April 3, 2017.

13

	William S. Good, Tim Valle, Curtiss O. Davis, Nicholas Tufillaro,Peter Spuhler, Chuck Hardsety, Conor Staples, Miltislit optimized
spectrometer: flight-like environment test results, Proceedingsof SPIE, Volume 9222.

14

5

	Korea Aerospace Research Institute (KARI); https://www.kari.re.kr/
eng.do.

15	Used with permission; Ball Aerospace; https://www.ball.com/
aerospace/programs/gems.

16

Entegris, Inc. | Scientific Report 2021

31

DOUBLING DOWN
ON EUV’S
DEFECTIVITY
CHALLENGES
Addressing Challenges
Beyond Stochastics
Authors: David R. Medeiros, Ph.D.
James A. O'Neill, Ph.D.

Background
Beyond the “traditional” challenges posed by node-to-nodedensity scaling, including finer resolution, tighter process
tolerances, ever-narrowing control over sources of defectivity,
and a general reduction in all sources of variability, the rapid
adoption of EUV technology for patterning in the sub-7 nm
era imposes at least two additional hurdles. These include
the impacts of sub-optimal pellicles for photomasks and theincreased influence of stochastic error in the imaging process.
To augment the progress in developing solutions to mitigate
these added challenges, it is also necessary to “over-achieve”
on the standard sources of variability, especially defectivity thatcan be mitigated. Most notably, cleanliness in mask storage
and handling must be taken to a new level as some manufacturers enter high-volume manufacturing without pellicles while
technologists continue to pursue better candidate pellicle
materials. Similarly, the cleanliness of all chemicals used in resist
processing must also be improved via filtration and purification
as chemical suppliers drive to innovative, unconventional
solutions like metal oxide resists that help address stochastic
variation. Even more disruptive is the advent of dry resists thatavoid all liquid processing in both coating and development,
overcoming the stochastic defects and diffusion-based limitations of conventional materials. A holistic view of lithographic
defectivity illustrates the challenges and opportunities thelong-awaited EUV era provides.

33

The Convergence of the
EUV and Automotive Eras
Despite the nay-sayers who have repeatedly declared“Moore’s Law is dead!”, semiconductor manufacturers
have made progress to create ever-smaller circuitry.
As the industry advances into the single-digit nodes,
among the technical breakthroughs that have brought
about this near continuum of device scaling are newmetallurgy, innovative gate stack materials, novel device
architectures, and increasingly complex patterning
schemes. All have enabled the continuation of Moore’s
Law.1 Despite the advancements, some fundamental
challenges continuously present themselves and only
become exacerbated at the smallest dimensions,perhaps most notably, variability. Process inhomogeneities, temporal fluctuations in tool performance, and,of course, random defectivity from undesired species,
are perpetual hurdles that need to be addressed before
achieving and sustaining robust manufacturing yields.
Defectivity is especially challenging in the patterning
area where the onset of EUV lithography has enabled
the progression to sub-30 nm pitch features, albeit withthe onset of increased impact of stochastic imaging
defects. Such defects, attributable to the random natureof traditional multi-component chemically amplified
resists and the relatively low photon flux for a given
exposure dose inherent with exposure at this highenergy wavelength of 13.5 nm (~92 eV), present anadded obstacle to be addressed while simultaneously
maintaining critical dimension precision and image
placement, or overlay, control.
Therefore, it is natural to look to drive all other“conventional” sources of defectivity – those not
attributable to the stochastic nature of the imaging
process – to as low a level as possible, and nominallyto zero. In fact, in all practicality, the industry needs todrive beyond current defect detection limits to attainthe levels being driven by the most stringent reliability
specifications, namely those of the automotive industry.
The “zero defects” target has become more than an
aspirational mantra as we consider the implications

34

and requirements of automation-assistance in current
vehicles and the ultimate move toward fully autonomous driving.2, 3 Instead, zero defects have become an
expectation of the end-user and a requirement for
the industry. As such, the expectation for both thesemiconductor manufacturer as well as the supplierof all comprising materials is to eliminate, in their
entirety, all extrinsic defects. The onus on the materials
supplier is accordingly also being cascaded to their
suppliers, creating a high-value quality supply chain
environment.

The Evolution of EUV
Extreme ultraviolet (EUV) lithography has been in thedevelopment phase for decades and was perpetuallycast as the “next generation lithography,” or NGL,
solution to enable extension of scaling consistent with
Moore’s Law. However, this revolutionary technology
was beset with significant technical challenges thatdelayed the adoption for high volume manufacturing
until relatively recently. The challenges posed by EUV
included 1) the availability of a reliable high-powersource of 13.5 nm photons, 2) suitably robust resist
materials that could achieve the resolution, image
quality, and photo speed requirements, and 3) advances
in mask making and characterization, to name the mostevident. The results of the combined efforts of theindustry have resulted in the adoption of EUV for the
7, 5, and 3 nm logic nodes and beyond by some of theindustry’s leading semiconductor chip manufacturers
as well as adoption more recently for advanced DRAM
applications. The accelerated pace at which EUV isbeing inserted into high-volume manufacturing, asshown in Figure 1, poses new challenges, especiallyconsidering that the dimensions of the next targeted
nodes are beginning to approach the limits of single
exposure for EUV. Double-patterning EUV may berequired as a bridging solution until high numericalaperture (NA) EUV is available for deployment in highvolume manufacturing in ~2025.

Scientific Report 2021 | Entegris, Inc.

90
80

N65

70
60
Minimum Half Pitch (nm)

N40

50
N28
N20

40

N14

30

N10

20

N7

N5

10
0

2006

2008

2010

2012

2014

2016

2018

2020

N3

2022

N2

2024

N1.4

2026

Figure 1. Approximate scaling roadmap of advanced logic offerings showing sustainment of Moore’s Law through the 1.4x node (N1.4).

Thus, we are currently experiencing a confluence oftwo paradigm shifts in the semiconductor industry:
1. the unprecedented demand for the tightest reliability
tolerances driven by automotive specifications,which mandate the zero-defect initiative, and2. the long-awaited adoption of EUV lithography forhigh-volume manufacturing in advanced logic and
DRAM nodes.
When coupled with the ever-increasing overall demand
for semiconductors resulting from the digital transformation currently so prevalent in virtually all aspects ofsociety, these dramatic shifts significantly raise the bar
for reduction of all sources of variability and morerobust defectivity mitigation strategies.

Entegris, Inc. | Scientific Report 2021

EUV Stochastics
As the industry progresses toward ever-smaller features,of particular concern are stochastic defects inherent
in EUV imaging. Stochastic defects are broadly definedas random errors that are induced by the imaging
process itself.4 That is, they are to be differentiated fromtraditional causal sources of patterning defects suchas those induced by microcontamination in photoresist or other processing media, airborne contaminants
that can compromise imaging, particulates or hazein photomasks, and aberrations in the optical path or
topography or backside contamination induced focus oroverlay shifts. Stochastic defects are instead classified asa printing failure that is unexpected due to the random
nature of the imaging process. While there is inherent
randomness in all lithographic imaging processes, suchas the composition of multicomponent photoresists andthe diffusion and reaction propagation that ensue upon
exposure, the high-energy nature of EUV photons makethis technology more susceptible to stochastics. Thisis especially important when the feature size being
imaged approximates the sphere of influence ofindividual photon-initiated events.

35

Relative to photons of 193 nm wavelength as in
ArF immersion lithography, EUV photons are morethan 14 times more energetic. This means that for acomparable dose and an equivalent volume element,
or voxel, of imaging material, there are ~14.3 fewer
photons. The scarcity of photons as nodes scale tofiner dimensions is illustrated in Figure 2. This graphplots the calculated photons for a voxel representativeof a typical line-end of a patterned line/space at theminimum feature size for each node, each at a constantaspect ratio of 2.2 and an exposure dose of 30 mJ/cm2.
Thus, as we scale from the 7 nm node (N7) to the 1.4 nm
node (N1.4), we are reliant on less than half as many
photons to define the patterned line-end. Therefore,
as scaling proceeds, imaging is significantly more susceptible to the impact of an errant photon inducing
unwanted photochemistry or conversely, not interfering the desired photochemical event. A more rigorous
treatment of “photon counting” and the confluent
effect of the randomness inherent in multicomponent
chemically amplified resists (CARs) is available in theliterature.5

Calculated EUV photon countper line-end voxel @ 30 mJ/sqcm

167

Addressing Resist Defectivity
Through Advanced Filtration

139

111
93
74

N7

N5

N3

N2

N1.4

Logic Node

Figure 2. Calculated EUV photon count per line-end voxel for logic
nodes at targeted minimum feature size with a constant aspect ratio(2.2) and exposure dose (30 mJ/cm2).

However, stochastic effects are only one source of
defectivity in EUV lithography. EUV is susceptible toall the traditional sources of defectivity and, again, by
nature of the scaling, the historical node-to-node
improvements need to be advanced at an even higher
rate to attain defect densities necessary for highyielding processes. Additionally, the industry is also

36

approaching another inflection point, in that detection
limits of defects, both from their source or how they
manifest on the wafer, are being pushed to the fullcapability. With the growing importance of long-term
reliability in semiconductors, such as those used incontrol and navigation in autonomous driving or in
medical diagnostics and treatment, latent defectivity
that is not detectable by conventional metrology
techniques or yield screening is becoming increasingly intolerable. It is necessary to no longer scale
defect densities at the historical trends but rather toover-achieve on these traditional sources to accountfor the advent of the impact of stochastics, as well as
the limits of conventional detection techniques. By
exploring the current trends of mitigation against
resist-based, airborne, and mask-originated defectsources, approaches for “non-linear” defect control
are proposed to extend EUV lithography to 2 nm nodeand beyond.

For multiple generations of technology, the importanceof tight control over resist contamination via point-ofuse (POU) filtration and the subsequent impact on
improved device yield has been an area of high activity
in semiconductor manufacturing. Continuous improvement in separation media, porosity scaling, and keen
insight into the interactions with photochemistry, have
led to sub-1 nm filtration of highly engineered membrane materials that afford the high yielding processes
the industry has come to expect and rely upon.6, 7
Figure 3 shows the various mechanisms of defectentrapment that have been engineered into advanced
filtration solutions for final POU photoresist filtration.
Furthermore, the importance of filtration and purification of the upstream components of the photoresist
formulation and the tight tolerances for unwanted
metallic species or other impurities have proven to
make the difference in the materials selection for
high-performance applications.

Scientific Report 2021 | Entegris, Inc.

Bottom antireflective coatings, or BARCs, havelong been a mainstay for reflectivity control for KrF
and ArF/ArFi patterning. Additionally, the ubiquitoususe of multilayer patterning to allow for thin film
imaging with both ArFi and EUV lithography havebrought about a deluge of new materials, each requiring
filtration solutions. Whether they are spin-on-carbons(SOCs), spin-on-hardmasks (SOHs), and organic planarizing layers (OPLs), or spin-on-glasses (SOGs) andsilicon-containing antireflective coatings (SiARCs), or
conventional organic BARCs, each innovative material
introduced to solve a patterning challenge, in turn,introduces a potential source of defectivity and, thereby,
requires a filtration solution. While with older generations of technology, traditional scaling of pore size
leading to more effective sieving provided suitablefiltration solutions, advanced nodes require tailoringof membranes to accommodate specific contaminants,
whether they’re metallic species, inorganic anions, ororganics such as oligomers or high molecular weightfractions of resist polymers. Customization by natureof membrane composition, or specialized surface
modification, allows for selective removals of theundesirable species.7 Increasingly, resist suppliers andend-users are moving toward serial filtration involving
specifically selected media and porosity in discrete
filter housings to allow for maximum efficacy of all
unwanted contaminants. The drive toward a true
“zero defects” state for patterning requires that all
sources be addressed.8 The growing trend towardfilter customization to address specific species is
expected to grow in coming years.

Sieving

Impaction

Metal Oxide Resists:
A Remedy for Stochastics?
In the last decade, entirely new resist systems havebeen developed to both avoid some of the random
nature of the multicomponent CARs, while simultaneously increasing the photochemical capture of the
scarce EUV photons by taking advantage of materials
with a high absorbance cross section at 13.5 nm.9
Through several generations of development of metaloxide resists, or MORs, high resolution with low degreeof variability has been demonstrated. These systems
employ a spin-cast film of nanoparticles of metaloxide precursor comprising a photosensitive ligand.
Upon exposure, this photosensitive ligand is cleaved
to leave hydroxyl moieties that subsequently condense
to form a metal oxide network, rendering the exposed
film insoluble in developer. Thus, a negative tone image
is formed, with the unexposed regions being readilysoluble. The discrete nature of the elements of the MOR
allow for high resolution, and the strong absorbanceof the metallic species afford an enhanced capture
and, in turn, relatively low photospeed. Of course,
as with CARs, MORs also require a suitable filtration
scheme as they too are subject to extrinsic defectivity.
It’s been found that careful selection of the membrane,porosity, and specific surface modification can afford
defectivity comparable to that of CARs.

Adsorption

Diﬀusion

Non-sieving

Figure 3. Retention mechanisms employed in resist filtration via targeted membrane selection. (Used with permission.7)

Entegris, Inc. | Scientific Report 2021

37

An alternative approach to MORs that take advantageof the discrete nature of the MO precursor and the highabsorbance cross section are the recently reported
dry resist systems.10 Researchers have taken a novel
approach and completely removed all solution-based
processing from the lithographic process. That is,rather than a spin-cast film, the resist is applied via a“dry” chemical vapor deposition (CVD). Instead of asolution-based developer, the three-dimensional
image is created directly via dry reactive ion etching(RIE). The benefit of the “all-dry” process is the avoidance of the diffusional effects that can be a source ofvariability in conventional photolithographic processing.
While such systems are relatively new to the industry,
they are garnering significant interest to help address
stochastics, particular for sub-3 nm nodes.

Mask Contamination:
The Killer DefectAs problematic to yield as resist contamination canbe, defects borne from particles or degradation of aphotomask, or reticle, can be catastrophic, since asingle “killer” repeater defect can cause a non-yielding
chip in each impacted field on multiple wafers or
multiple lots of wafers. The economic impact of asingle defect cannot be overstated. Therefore, chip
manufacturers go to great lengths to ensure that
reticles remain in pristine condition throughout theiruseful lifetime in the fab, including during transport
to the fab and through multiple lithography scanners.
Again, the stakes for EUV are even higher than with
DUV lithography, as not only are the critical dimensionsof the printed features smaller, only recently have
manufacturing-worthy pellicles been introduced tohigh volume manufacturing. Preventing contaminationof reticles is highly dependent on the protocols fortransport, inspection, cleaning, and usage within thefactory as well as the storage containers in which they
are housed when not in use. The use of a dual-pod
system comprised of an inner metal pod that securely
holds the reticle in place providing protection fromshock during movement, and a plastic outer pod thatinterfaces with existing factory infrastructure, has

38

proven to be the industry-standard ensuring long
usable lifetimes for these expensive reticles.11 This
pod-within-a-pod design provides a highly effective
barrier to particulates, airborne contamination, moisture, electrostatic discharge, and other sources ofpotential contamination or degradation. The form
factor of dual-pod system is available for both reticles
that use pellicles as well as those that do not.
While reticle pods are essential for extended lifetimeand storage of EUV photomasks, pellicles form thelast line of defense. The challenge for selecting amaterial of construction for an EUV pellicle requiresthat the material be highly transparent at 13.5 nm,
durable enough to withstand repeated exposure on
92eV photons without perturbation of its optical andmechanical properties, and able to be fabricated intoa uniform film capable of mounting onto a full areaof a reticle. Recall as well that as EUV masks are reflective, the radiation passes through the pellicle twice,in contrast to transmissive DUV masks, where lightpasses through just once. Development of polysiliconpellicles has reached a state where it provides upwardsof 90% transmission of EUV and suitable durability, andmanufacturability is considered a viable solution forhigh volume manufacturing. Polysilicon pellicles arebeing readily adopted for use in today’s 0.33 NA EUV
systems. However, the source power scaling roadmap
suggests the need to raise source output to >500 W,
and a new material will be required to withstand cumulative exposure doses in the ranges being projected.
Researchers at imec have reported on the use of carbon
nanotubes (CNTs) for a next generation EUV pellicle.12
CNTs can be made into a relatively high porosity filmof considerable strength that has proven to effectively
prevent particulates from reaching the reticle surface.
The high porosity affords excellent transmission at
13.5 nm, exceeding 95%.12 While CNTs have themechanical integrity and optical properties to makethem strong candidates, they do experience a degreeof degradation in the presence of the low levels ofhydrogen gas in the EUV system. As such, current
focus is on post-processing of CNTs to make thema viable candidate for high NA EUV.

Scientific Report 2021 | Entegris, Inc.

Conclusions
The near simultaneous adoption of EUV lithography
for advanced node semiconductor manufacturing
and the advent of the automotive specifications forreliability and zero defects have posed an extreme set ofchallenges for variability reduction and contamination
control. Stochastic imaging defects become impactfulat fine critical dimensions and with the use of highenergy EUV, driving a required “over-achievement” inother sources of defectivity. Advances are required inresist filtration, stochastic-tolerant resist systems, andmask defect prevention, all of which need to seamlessly
dovetail into the EUV ecosystem, which is highly dependent on these solutions. A comprehensive approach asafforded by the extensive portfolio of Entegris offerings
is necessary to enable implementation of high NA EUV
systems with high power sources to further sustain
scaling at a historical pace and meet the needs ofthe automotive era.

References	International Roadmap for Devices and Systems (IRDS™) 2020
Edition, IEEE publication (2020)1	Automotive Zero Defects Framework, Automotive Electronics
Council: AEC-Q004, (2020)2	A. Aal, J. Braggin, A. Amade, M. Puttock, Addressing Weak Links in
Automotive Reliability Semiconductor Contamination Control,
Inspection and Test, 2020 IEEE International Integrated Reliability
Workshop (IIRW), (2020)3

	P. DeBisschop and E. Hendrickx, Stochastic Printing Failures in EUV
Lithography, Proc. SPIE, 10957 (2018)4	W. D. Hinsberg, G. M. Wallraff, M. I. Sanchez, N. Megiddo, O. Kostko,
Contribution of EUV resist counting statistics to stochastic printing
failures, J. of Micro/Nanopatterning, Materials and Metrology, 20,(2021)

5

	EUV Enablement: Solving Defect Challenges in the EUV Process,Entegris white paper, (2020)6	Kohyama, F. Kaneko, A. Gjoka, J. Jaber, Bridging the Defect Gap in
EUV Photoresist, Proc. SPIE, 10960, (2019)7	B. Tufts, Trends and Observations in Materials Quality at Advanced
Process Nodes, Strategic Materials Conference Korea (2021)

8	J. Stowers, J. Anderson, B. Cardineau, B. Clark, P. DeSchepper, J.
Edson, M. Greer, K. Jiang, M. Kocsis, S. Meyers, A. Telecky, A.
Grenville, D. DeSimone, W. Gillijns, G. Vandenberghe, Metal Oxide
EUV Photoresist Performance for N7 Relevant Patterns andProcesses, 9779, (2016)9	R. Wise, Breaking Stochastic Tradeoffs with a Dry Deposited and Dry
Developed EUV Photoresist System, Proc. SPIE, 11612, (2021)

10	Enabling Advanced Lithography: The Challenges of Storing andTransporting EUV Reticles, Entegris white paper, (2019)11	E. Gallagher, M. Y. Timmermans, I. Pollentier, J.U. Lee, M. Mariano, C.
Adelmann, C. Huyghebaert, F. Scholze, C. Lambis, CNTs in theContext of EUV Pellicle History, Proc. SPIE, 10583, (2018)12

Entegris, Inc. | Scientific Report 2021

39

DELIVERINGTHE THERAPIES
OF THE FUTURE
The Role of Aramus™
Single-use Assemblies
Author: John B. Lynch, Ph.D.

COVID-19 Accelerates
Expansion into Life Sciences
Several years ago, Entegris’ leadership team recognized thepotential application of its process capabilities developed forleading semiconductor manufacturers to the life sciencesindustry. Both industries require some of the most advanced
manufacturing capabilities in the world. Both industries require
high-purity specialty chemicals and materials; specially designed
systems for fluid management, storage, and transport; and thestrict control of particles to prevent contamination.
For different reasons, both industries have an intense focus on
eliminating process variation during production. In the case of
semiconductors, manufacturers need to ensure the reliability
and performance of the integrated circuits they produce while
also achieving high yields. In life sciences, the objective is toincrease efficacy and to prevent toxic side effects. In life
sciences, validation also is critical.
While the desired results differ, process control is the means forachieving the necessary results in both industries, especially inthe life sciences segment of bioprocessing where the process
is the product.

Aramus 2D single-use assembly.
41

Entegris’ World-Class Technologies Include:
Liquid Packaging
We provide innovative, safe, high-purity liquid packaging and delivery systems, designed
to maintain the safety, reliability, and integrity of biopharmaceutical products. Along withliner-based systems that ensure safe transport, containment, and dispense of process
fluids, we offer a number of containment solutions for stationary and mid-range
mobile applications.

Single-Use Assemblies
Our single-use assemblies provide purity with faster time-to-market while protecting
process quality, efficacy, and efficiency. From the early stages of R&D to the final fillingstage, we deliver high performing, inert, and low extractables and leachables (E&L) solutions
for single-use and full-scale processes. Our solutions make it possible to safely transport,
store, and dispense reagents and solvents for DNA, peptide and protein synthesis, active
pharmaceutical ingredient (API) manufacture, and fermentation.
Fluid Management
For decades, we have been ensuring materials integrity with quality fluid management
systems and related services to the semiconductor and chemical processing industries.
With this expertise, we offer nonmetallic solutions that meet the needs of biopharmaceuticalas well as bulk and finishing pharmaceutical industries, specifically for steam-in-place (SIP)
and clean-in-place (CIP) applications.

Filtration and Purification
Our advanced materials technologies enable us to deliver high-purity and validated productsthat achieve reliable performance. We manufacture leading-edge polymeric membranes andsterile filtration cartridges for a wide range of life sciences and pharmaceutical applications
including buffer and intermediate filtration.

Particle Characterization
Subvisible particle detection is a critical challenge faced by companies developing andmanufacturing parenteral drugs. Our particle characterization solutions enable customers
to perform single or automated tests on parenteral drugs following USP <788>, therapeuticproteins per USP <787>, ophthalmic solutions per USP <789>, and lipid emulsion per USP<729>.

Organophosphorus and Fine Chemicals
N(i-Pr)2
NC

O

P

N(i-Pr)2

For small molecule and oligonucleotide based pharmaceutical actives, we excel in thedevelopment, scale-up, and manufacture of high-quality intermediates, phosphorylating
agents, key synthesis reagents, phosphine ligands, and catalysts. We provide creative
solutions including options for custom synthesis, specifications, packaging, anddelivery logistics.

Organosilanes and Other Specialty Chemicals
Me3SiO
Me3SiOSiR

OSiMe3R = halogens, NH2 ,amides, NCO,
acryloxy

42

Utilizing our 40 years of specialty chemical expertise, we partner with a range of companies
from novel contact lens manufacturers to wound care companies to prominent global life
sciences businesses. Our best-in-class chemical competencies include unique monomers
and polymers, organosilicon compounds and methacrylates, and stable isotope labeling.
Custom synthesis is available and we can tailor chemicals to a customer’s exact specifications.

Scientific Report 2021 | Entegris, Inc.

It is this rigorous focus on process capabilities in the
fabrication of semiconductors that created an opportunity for Entegris in the production of pharmaceuticals
for the life sciences industry. Today, Entegris is playing
a crucial role in the development and manufactureof therapies for COVID-19 and is a key supplier of the
Aramus™ single-use high purity assemblies to someof the major companies working on and distributing
vaccines.
Like Entegris’ semiconductor customers, our pharmaceutical customers rely on our state-of-the-art global
supply chain. We leverage our global infrastructure with
regional R&D and manufacturing facilities to address
specific customer needs with customized applications
and solutions. Through a highly collaborative customer
engagement model, we gain a clear understanding ofeach customer’s unique challenges. From small to large
molecule drug manufacturing, we work to reduce
the risks associated with a complex manufacturing
process and to deliver world-class quality with reliablebatch-to-batch consistency.

Biotherapeutics and Bulk
Drug Storage and Transport
The dominance of biologics on the top pharmaceutical
drug blockbuster list is evidence of the therapeutic
success and rapid growth of biologics.1 The COVID-19
pandemic is a powerful example of how important biotherapeutics are for treatment of the virus and, ultimately,
prevention through the availability of vaccines.
The overall process to produce biotherapeutics
has three main steps:
1. Upstream, which includes growing the therapeutic
in a bioreactor
2. Downstream, which includes several purification steps
3. Final fill, in which the bulk drug is transferred into vials
or syringes for distribution of the actual drug product
Biopharmaceutical therapy development and manufacture is proliferating because of scale-up in biosimilars
and scale-out in emerging cell and gene therapies.
This requires successful distribution between process
sites from where purification is completed to the site

Entegris, Inc. | Scientific Report 2021

where final fill of the drug product is performed. These
steps are often decentralized for added manufacturingflexibility, since final fill and finish processes are notbound by time-dependent active pharmaceuticalingredient (API) product factors and can therefore be
utilized at a higher rate than API production processes.
As the global clinical pipeline expands with more
complex and temperature-sensitive products, thedistribution of high-value APIs between development
sites, clinical sites, and drug manufacturers for further
processing will become a more relied upon paradigm.
This is the case in the ongoing race to develop treatments for COVID-19, which requires a temperaturecontrolled distribution network that can quickly scale
up to meet huge demands. Over the 2018 – 2024
period, cold chain products are expected to grow atnearly twofold the rate of non-cold chain.2 As cold
chain grows, effectively managing and mitigating its
associated risks will be critical.
Cold chain consists of the freezing of heat labile
APIs to below subzero temperatures for storing andtransporting the frozen product followed by thawing
for subsequent manufacturing and production. The
current implementation of single-use technologies(SUT) is reducing operating costs and mitigating thecontamination risk of traditional stainless-steel freezingtanks and bottles through batch flexibility, lower storage
density, and controlled freezing – all in a sterile closed
system. However, under frozen temperature, thesepolyolefin single-use components are brittle andprone to failure that can lead to product loss andcontamination.
In addition, transport presents significant risk – it is the
only part of the production process that is outside of
the manufacturer’s process control. Even within thecold chain end-to-end process (Figure 1), the frozen
distribution of product is where significant failure canoccur from various unknown mechanical and thermal
shocks experienced along its route. Mechanical damage
typically results in 3–5% product loss from bag breakage
in frozen bulk drug cold chain handling, and mostpharmaceutical end users see temperature excursions
in their shipments. Forty-three percent of those end
users see excursions that exceed four degrees, whichis enough to harm their product.3

43

Fill

Freeze

Store

Ship

Transfer

Thaw

Transfer

Dispense

Figure 1.

To further quantify this impact, the industry sees a$35 billion loss annually from failures in temperaturecontrolled logistics.4 It is vital then, to have a singleuse product packaging system that functions underthese conditions. However, these systems are often
not appropriately qualified to avoid failure or maintaintemperature because their challenging distribution
environments are not fully understood. Fortunately,
the risks of single-use bags in frozen shipping canbe mitigated by following the approach of:

expect our high-purity bags like the Aramus assemblies that are ideal for freezing, transporting, storing,and thawing drug substances will be key to the therapies of the future.

• Employing sensors for monitoring criticalshipment parameters• Utilizing more suitable low-temperaturematerials and packaging• Qualifying and evaluating through simulated
standards and testing in real-world transit lanes
Implementing these guidelines increases visibility into
the distribution lane, incorporates robust materials,
and qualifies them against relevant metrics to ensure
consistent product quality in cold chain.

Collaborating withLife Sciences Customers
to Deliver the Therapiesof the Future
Entegris’ innovation, manufacturing excellence, andcommitment to quality and leadership in purity arevalued in the life sciences industry’s race to deliver a
global supply of vaccines for COVID-19. Similarly, we

COVID-19 mRNA vaccine.

These will include biologics and cell therapies as wellas traditional and mRNA vaccines. We are excited andoptimistic about the role that our broad portfolio willplay as we continue to collaborate and partner withcustomers to solve the most demanding manufacturing challenges in the evolving life sciences industry.
References	Stephanie Yip, Top 10 Best-Selling Drugs of 2019,https://pharmaintelligence.informa.com/resources/productcontent/top-10-best-selling-drugs-of-2019.

1

	Basta N., Lipowicz M., 2020 Biopharma Cold Chain Sourcebook,11th Edition, Pharmaceutical Commerce.

2	2019 Biopharma Cold Chain Logistics Survey, Pelican Biothermal.

3

	QVIA Institute for Human Data Science.

4

44

Scientific Report 2021 | Entegris, Inc.

Innovation ThroughCreativity and Collaboration~2,600registered, live patents~1,100pending patent applications~29

Third party collaborators, someintellectual property is exchanged

Patent Portfolio
648

200 inventors from 7 countries
contributed to portfolio in 2020

424

Registered Patents by Geography
330

Actively license and monetize
dynamic global patent portfolio

322

299

109

84

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32

31

29

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121

Global R&D and Tech Centers for
Collaborative Customer Engagement

Bloomington
ChaskaColorado Springs
San Luis Obispo
BurnetDecatur

Life
Life Sciences
Scie
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Technology Center
Korea Technology Centeri2M CenterFranklinTokyo
China Technology Center

Danbury Technology Center
Taiwan Technology Center
Kulim
Singapore

R&D Lab

Application Lab

Contributor Credits
James A. O’Neill, Ph.D. | Senior Vice President and Chief Technology Officer
Articles: Enabling the Smartphone Evolution – 10 years on the Leading Edge of Technology;
Doubling Down on EUV’s Defectivity Challenges – Addressing Challenges Beyond Stochastics
Dr. O’Neill joined Entegris in 2012 and now serves as chief technology officer. In that role, he leads
Entegris’ innovation process directing the development of new products and a global network oftechnology centers where Entegris’ engineers and scientists collaborate with customers to develop
solutions to their most advanced technical challenges. Prior to Entegris, Jim led several semiconductor
technology development programs at IBM.

Wenge Yang, Ph.D. | Vice President, Market Strategy
Article: Enabling the Smartphone Evolution – 10 years on the Leading Edge of Technology
Dr. Yang joined Entegris in 2012 to lead the company’s market strategy. In his role, he is responsible
for product and market strategy, market research and market trend analysis, strategic marketing, andmaintenance of the company’s strategic technology roadmap. Prior to joining Entegris, Wenge wasan equity research analyst at Citigroup covering the semiconductor equipment and materials sector.
He also served in various executive roles at Advanced Micro Devices and Tokyo Electron.

Jennifer Braggin | Divisional Communications Manager – Microcontamination Control
Article: A dvancing Autonomous Electric Vehicles – Smart Materials and Detailed Unit Process Design
Become Key Drivers
While holding various roles in technical marketing and engineering management at several companies,
Ms. Braggin's career has focused on improving manufacturing yields, enhancing training efforts, andcommunicating technical achievements to international customers and partners. A life-long learner,
Jennifer is also a lecturer at the Gordon Institute at Tufts University where she oversees the engineering
management minor and teaches engineering management and leadership courses.

Mark Puttock ,Ph.D. | Senior Director, Advanced Tech Engagement, Office of the CTO
Article: A dvancing Autonomous Electric Vehicles – Smart Materials and Detailed Unit Process Design
Become Key Drivers
Dr. Puttock has worked in the semiconductor industry over 30 years. With a broad understandingof technology trends, Mark collaborates with Entegris’ global product development teams to develop
timely and differentiated new materials and components for the world’s leading semiconductor
manufacturers.

Montray C. Leavy, Ph.D. | Deputy Chief Technology Officer
Article: From Prototype to High Volume Manufacturing – Entegris’ AM Journey
Dr. Leavy is based in Singapore and leads the advanced technology engagement team, which is
responsible for creating and implementing technology roadmaps while ensuring alignment withcustomers’ new product initiatives and industry trends. The team also identifies and implements
new technologies and capabilities to achieve Entegris’ future technology objectives. Earlier in his
career, Montray served as vice president of account technology at ATMI where he delivered tailoredmaterials solutions for customers’ most critical technology processes.

46

Scientific Report 2021 | Entegris, Inc.

Subhash Guddati | Technology Director, ATE, Office of the CTO
Article: From Prototype to High Volume Manufacturing – Entegris’ AM Journey
Mr. Guddati has 18 years of experience in product development, process improvement, and program
management in R&D and manufacturing environments. He has notable achievements in data storage(hard disk drives) and additive manufacturing. Subhash has a keen eye for integrating emerging
technologies like additive manufacturing, digital threads, and blockchain technologies for productdevelopment and manufacturing processes. His current responsibilities focus on expanding Entegris’
R&D capabilities in Singapore.

Wayne Hambek | Director, Industrial Project Management – Specialty Chemicals andEngineered Materials
Article: State-of-the-Art Space Optics – Innovative Materials for a Challenging Environment
Mr. Hambek has been involved in developing new products and new markets for Entegris’ SCEM
division for over eighteen years. He has successfully introduced products in diverse fields including
jet engine components, biomedical implants, and alternative energy and has been instrumental in the
optics community’s development of best-in-class components and systems. Wayne serves as one ofthree Entegris representatives to the Center for Freeform Optics, a government-university-industry
collaboration focused on advancing state-of-the-art optics technology.

Troy Scoggins, Ph.D. | Director, Technology – Specialty Chemicals andEngineered Materials
Article: State-of-the-Art Space Optics – Innovative Materials for a Challenging Environment
Dr. Scoggins has over 23 years of experience with Entegris in scientific and technical leadership roles
focused on silicon carbide and graphite technologies as well as semiconductor gas purification. In
2009, he was named director of the technical development organization for Entegris' POCO Materials.
Troy's role was recently expanded to include responsibilities in the SCEM division associated withportfolio management, computational modeling, and cross-divisional programs.

David R. Medeiros, Ph.D. | Senior Director, Engineering, Office of the CTO
Article: Doubling Down on EUV’s Defectivity Challenges – Addressing Challenges Beyond Stochastics
Dr. Medeiros joined Entegris in spring 2021 with over 30 years in the semiconductor industry, primarily inpatterning technology. He is leveraging his extensive experience leading R&D, high-volume manufacturing,and central planning teams as well as his deep knowledge of chemistry and organic materials to develop
a comprehensive lithography strategy for Entegris that is highly focused on the rapidly expanding areaof EUV technology.

John B. Lynch, Ph.D. | Vice President Life Sciences
Article: The Race for COVID-19 Vaccines – The Role of Aramus Single-use Assemblies
Dr. Lynch has a passion for leveraging science and technology to improve health and wellbeing. He has
more than 30 years of scientific, technical, and business leadership experience focused on innovationand growth in the life sciences and other markets. John has served as vice president of life sciences at
Entegris since 2019, after joining the company in 2017 with responsibility for new market businessdevelopment.

Editor-in-Chief James A. O'Neill, Ph.D.
Editorial Reviewers Michael Besnard, Arlene Hornilla, and Jennifer Braggin
Content and Creative Directors Connie Chandler and Anna Anderson
Graphic Designer Gwendolyn Reule

Entegris, Inc. | Scientific Report 2021

47

CONTENT AND LIABILITY DISCLAIMER
Entegris believes the information in this document is accurate as of its publication date. Any and all specifications and designs
are subject to change without notice. Entegris is not liable for errors or omissions in this document. Entegris undertakes noobligation to update the information presented in this document. You may not use or facilitate the use of this document inconnection with any infringement or other legal analysis concerning Entegris products described herein. You agree to grant
Entegris a non-exclusive, royalty-free license to any patent claim thereafter drafted which includes subject matter disclosed
herein. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this document.

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