Why Your Smartphone Screen Will Be Made of ASF®-Grown Sapphire
0 Why Your Smartphone Screen Will Be Made of ASF®-Grown Sapphire
Table of Contents
1 Executive Summary
2 The Future of Cover Glass isn’t Glass
3 Expanding Sapphire beyond Traditional Markets
4 Sapphire Crystal Growth Furnaces
5 Looking at Sapphire Growth through a Value Metric
6 Sapphire Crystal Growth Value Metric KPIs
7 Why Uniform Boule Geometry Matters
8 Beyond the Boule – Factors Impacting Cost of Ownership
9 ASF® - The Path to Low Cost Sapphire Production
1|Page
Why Your Smartphone Screen Will Be Made of ASF®-Grown Sapphire
Executive Summary
Consumers have long complained of scratched and broken screens on their smartphones. Yet, in spite of improvements in
strengthened glass, the problem still persists, and consumers and brand owners are looking for a better solution. Sapphire
crystal offers long-proven advantages in scratch-resistance and durability over reinforced glass, and smartphone and wearable
brand owners are beginning to introduce products with sapphire cover screens.
For sapphire to achieve a bigger share of the cover screen market, brand owners have to be reassured that the material will be
available at high volumes and at the price points they need to drive broader adoption within their product lines and meet their
bottom line needs as well. Getting there depends on two important factors – creating a supply chain with an abundance of
high quality bulk sapphire crystal and an optimized fabrication supply chain capable of turning that bulk crystal into high
performing sapphire cover screens.
Building a supply chain capable of producing sapphire crystal at the volumes needed to meet the demands of the cover screen
market poses a different set of crystal growth challenges over traditional, lower volume markets such as LED and other
industrial application segments. The cover screen market favors a growth method that can deliver the highest amount of
yielded material from each boule.
Bulk crystal growers are facing significant capital expenditures as they increase their capacity to meet the expected future
volume of sapphire material for the cover screen market. It is critical that they make the right choice of crystal growth
equipment to ensure they not only optimize their production capability, but also ensure the highest return on their investment.
But which type of sapphire growth equipment is best optimized for the cover screen market? The authors look at the two most
widely used growth methodologies – Kyropoulos (Ky) and GT’s ASF® process based on the heat exchanger method (HEM) to
understand which one is best optimized to meet the needs of the cover screen market.
The authors present a Value Metric that compares the critical key performance indicators between ASF and KY furnaces. By
looking at the most important bulk crystal growth factors, GT’s ASF furnaces deliver more value to sapphire producers targeting
the smartphone cover screen market. The ASF furnace not only produces more yielded material from each boule, but it requires
fewer furnaces and operators than a KY plant of equivalent capacity.
2|P a g e
Why Your Smartphone Screen Will Be Made of ASF®-Grown Sapphire
How often has this happened to you, or to someone you know? Too often many of us
have experienced the feeling captured on the woman’s face in this picture as our
smartphone screen shatters from an accidental drop or gets scratched during
everyday use. We try to prevent this from happening by spending up to $40 USD or
more on a wide range of aftermarket products to protect our devices. Yet in spite of
this, cover screens still crack and shatter. A PV Advisor poll conducted in July of 2013 of
1,500 UK adult iPhone users with damaged devices revealed that their phones were
damaged on average within10 weeks from the purchase date – the most common
issue being a broken screen. Advances in strengthened glass material have improved
the performance of the screen, but the problem still persists, and it is a problem for
both users and brand owners alike.
The Future of Cover Glass Isn’t Glass
Why not eliminate the problem in the first place with a better cover screen material? A
survey conducted by uSell.com (via NBC News) in the fall of 2014 ahead of the Apple
iPhone 6 rollout asked over 1,000 US smartphone owners what current smartphone
features they thought were the most important. Thirty seven percent of the people
surveyed wanted longer battery life, and 19 percent wanted a larger screen. Topping
the list of new features, at 45.5 percent, were people asking for sapphire cover screens.
Though the iPhone 6 did not launch with a sapphire screen, other device makers are
not waiting to follow Apple’s lead and are turning to full crystal sapphire cover screens
to replace strengthened glass on their current or future products.
Despite efforts to improve the screens on
our smartphones they still scratch and
break in everyday use causing a problem for
users and brand owners alike.
The use of solid crystal sapphire for luxury watches is well known. As figure 1 shows, a
growing number of brand owners are turning to sapphire to sapphire as the cover
screen material to protect not only smartphones, but also the fast-growing number of
smartwatches entering the market. Much has been written about the properties of
sapphire that make it a ideal material choice for products such as smartphones and
wearable devices. It is an extremely durable material that resists cracking and
scratching. There are only a few other materials that can actually scratch solid crystal
sapphire making sapphire a superior material for products that undergo the kind of
daily wear and tear our smartphones go through. A few smartphone manufacturers
are marketing a poorer quality “sapphire-like” product using an amorphous coating,
usually aluminum oxide, applied to glass. These screens offer little or no improvement
over strengthened glass screens and come nowhere close to providing the scratch
resistance of a full, solid sapphire crystal cover screen.
So why is sapphire not more widely used in these products? The adoption of sapphire
for these high volume devices depends on many factors. This paper focusses on the
role that bulk crystal growth plays in making sapphire material more widely available
and at price points that will drive its adoption into the consumer electronics market.
Figure 1
A growing number of device makers are
turning to sapphire as the material for their
cover screens
3|P a g e
Why Your Smartphone Screen Will Be Made of ASF®-Grown Sapphire
Expanding Sapphire beyond Traditional Markets
The ability to deliver high quality sapphire material in volume and at the prices brand
owners need begins with bulk crystal growth. There are a number of well-known
crystal growth methodologies such as Kyropoulos (KY) and Heat Exchanger Method
(HEM), to name two of the most widely used, that have been producing quality
sapphire material for many decades. Until recently, the need for high volumes of large
diameter sapphire material didn’t exist since most of the material being produced was
targeting lower volume niche applications with relatively high margins serving the
optical, aerospace and other industrial markets. The historical best-known-methods
for producing boules and fabricating sapphire parts were optimized around the
material requirements driven by these respective applications.
The introduction of LED lighting in the early 2000s created an inflection point in the
growth of the global sapphire industry. Crystal growers and fabricators quickly
increased capacity to meet the fast-growing demand for 2-inch sapphire epi-ready
wafers. At the time, LED light bulbs were significantly more expensive than traditional
incandescent light bulbs driven mostly by a supply chain that had been optimized
around traditional, lower volume sapphire markets. Walk in today to your local home
improvement store and see a wide range of LED light bulb choices at prices that have
dropped significantly compared to 10 years ago. Technology improvements, along
with supply chain optimization and an overcapacity of sapphire production contribute
to these lower costs.
Sapphire Crystal Growth Production Equipment
The demand for small diameter, 2-inch LED material fueled the growth of the global
sapphire industry and created opportunities for material producers to increase
production to meet rising demand. This growth also created an opportunity for the
development of a merchant sapphire equipment market where none existed before.
This dynamic favored KY equipment over other crystal growth equipment such as
HEM.
Up until 2010, most of the global bulk sapphire crystal was produced using KY or
modified KY crystal production furnaces. Much of this equipment was provided by a
small number of Russian-based suppliers who provided the basic KY system, but
offered little in the way of installation services and ongoing product service and
support to the customer. That changed with GT Advanced Technologies acquired
Crystal Systems in July of 2010.
Sapphire (9) ranks second in hardness on
the Mohs scale, a long accepted
measurement of material hardness.
Created in 1812 by the German geologist
and mineralogist Friedrich Mohs, the scale
rank orders from hardest (diamond) to
softest (talc) materials in terms of their
resistance to scratching by a harder
material.
Scratch resistance is only one measure of a
material’s suitability for use as a cover
screen. Other factors that impact
performance are the material’s dielectric
constant, flexure strength and optical
clarity. In addition to these mechanical
properties, the cost of producing sapphire
is another important driver for sapphire
cover screen adoption. Crystal growth and
fabrication techniques can greatly impact
the overall cost of sapphire.
GT has extensive experience in sapphire
crystal growth and the fabrication of
sapphire for use as cover screen material.
GT, in partnership a leading sapphire
fabricator, will be publishing a series of
white papers in the coming months that
will examine the metrics that matter most
in bulk crystal growth and sapphire
fabrication optimization that deliver
optimal performance of sapphire cover
screen material.
At the time of the acquisition of Crystal Systems, the HEM growth process, developed
by Fred Schmid and Dennis Viechnicki in 1967, was a captive crystal growth process
being used at Crystal Systems where Fred was the CEO. Unlike KY equipment, HEM
production equipment was not commercially available to other crystal growers. As a
result, more of the LED sapphire material was being produced on KY systems than
other growth methods. However, as the industry demand for higher volumes of 2-inch
cores grew, Crystal Systems was already delivering LED-grade sapphire material to
4|P a g e
Why Your Smartphone Screen Will Be Made of ASF®-Grown Sapphire
some of the most demanding customers in the industry. In fact, by the time GT
Advanced Technologies acquired Crystal Systems in July of 2010, they were providing
large diameter 4-inch and 6-inch cores and receiving excellent quality reports from its
customers. The reason more LED material is based on KY material has more to do with
the fact that most of the LED epi-ready wafer suppliers had already standardized their
MOCVD processes around 2- inch KY material. There was little incentive for a wafer
provider to disrupt their qualified epitaxy process by introducing a new material into
the mix.
The strategic driver for GT’s acquisition of Crystal Systems was to commercialize a
highly scalable and easy-to-operate sapphire growth system based on the HEM
process to meet the growing demand for more bulk sapphire crystal. GT had already
demonstrated success in developing market-leading technology, implementing
service and support resources and developing a robust, scalable Asia-based global
supply chain in the solar industry with its DSS™ multicrystalline ingot furnaces. GT
successfully leveraged this experience by installing over 300 ASF furnaces within the
first two years of the Crystal Systems acquisition.
GT’s ASF® sapphire furnaces are installed at
customer sites throughout Asia producing
high quality material for a range of
applications including LED, optical, watch
crystals, smartphones and other consumer
products. The ASF furnace produces large
boules with uniform geometry that are
optimized for delivering the highest amount
of yielded material at high volumes for
consumer electronic applications.
The dimensional requirements of 2-inch LED wafers does not necessarily favor one
growth method over another since each of the most widely used methods can deliver
high quality 2-inch diameter cores at reasonable cost. But this changes as material
diameter increases. Now, the scalability of the growth process and its ability to
produce more uniform and larger boules becomes more critical in the equipment
purchase decision. Yielded material per production run, becomes more important as
the application drives the need for large area products. For the LED industry this
means material cost goals will favor a highly scalable process such as HEM to deliver
material as the industry transitions from 2-inch wafers to 4-inch and 6-inch wafers in
the coming years. For mobile devices where volume requirements are extremely high
and costs are low, delivering the highest amount of useable material per boule is not
an option, it is a requirement. These application requirements will favor the HEM
process over existing growth processes because of its ability to scale to much larger
boule sizes that deliver high yields.
Looking at Sapphire Growth through a Value Metric
One of the arguments often heard from the suppliers of strengthened glass is that
sapphire will never be cost competitive with glass cover screens because of the high
cost of manufacturing. Delivering low-cost sapphire material begins with boule
growth. Understanding the relationship between cost and crystal growth and the
differences between the various growth methods can be expressed in the concept of a
Value Metric. A Value Metric is a way to quantify a certain value derived from a set of
key performance indicators (KPIs) that are the most important criteria affecting the
data you are trying to measure in terms of comparative value. For the purposes of this
paper, we will use a Value Metric to demonstrate which sapphire growth method, KY
or GT’s ASF® process is best optimized for producing large area cover screen material
for high volume production environments.
5|P a g e
Why Your Smartphone Screen Will Be Made of ASF®-Grown Sapphire
A Value Metric based on the key performance indicators
(KPIs) that impact sapphire growth and the resulting yielded
material will help to reveal the answer. To determine the
answer to our question we have constructed the following
Value Metric (see figure 2).
Our scenario begins with a phone call from a customer that
wants to place an order for 10 million sapphire cover glass
screens per year. To deliver this quantity of material you will
need to increase your current KY production capacity with
additional sapphire growth furnaces. Your choices are either
standardizing your production around KY furnaces or GT’s
ASF furnaces. As a crystal grower, you have experience with
the KY growth method, but are concerned that small boule
sizes these furnaces produce will require a significant
number of new furnaces to meet the targeted production
volume. You have some general information about ASF
furnaces and the HEM process from your conversations with
people in your engineering and operations teams, and from
your industry peers. What you have been told is that KY
furnaces are much less expensive than ASF furnaces, but
ASF furnaces typically produce a larger boule than a KY
furnace. To help you make this business-critical decision
you develop a Value Metric based on the most important
crystal growth KPIs. For our comparison in this scenario the
KPIs include the following:
Annual screen
production
(millions)
Charge size (kg)
Cycle time (days)
Boules per year
Screens/boule
Screens/furnace
/year
Boule run yield
Adj. screens/
Furnace/year
Total furnaces
Furnaces per
operator
Operators per 12
hour shift
Total Operators
(3 shifts / week)
ASF 165 Kg
Boule
KY 85 Kg
Boule
KY 30 Kg
Boule
10
10
10
165
23
85
17
30
12
15.2
2,364*
35,974
20.6
1,050*
21,618
29.2
420*
12,250
90%
32,377
60%
12,971
80%
9,800
309
12
771
6
1,020
10
26
128
102
77
385
306
Figure 2: *estimated output after production optimization (result will
vary based on customer-specific processes and requirements)
Sapphire Crystal Growth Value Metric KPIs
Charge size – the size of the boule each furnace is capable of producing on a
repeatable basis at volume production measured in kilograms.
Cycle time – the amount of time it takes to produce a boule.
Number of boules produced in a year – for our value metric formula we will use 350 days
divided by the cycle time.
Yielded cover screens per boule – this is a critical number as it measures the amount of
good material that can be fabricated into cover screens that each boule is capable of
producing.
Yielded cover screens per furnace per year – this will reveal how many cover screens each
furnace is capable of producing on an annual basis by multiplying the number of
boules it produces by the number of yielded cover screens per boule.
Number of furnaces needed to meet customer delivery – by simply dividing the number
of screens that need to be delivered by the number of yielded screens for each furnace
you can calculate the number of furnaces that will need to be purchased to satisfy the
customer order.
Number of operators needed to run factory – this is important as it impacts personnel
costs and overall plant operations.
6|P a g e
Why Your Smartphone Screen Will Be Made of ASF®-Grown Sapphire
Figure 2 compares three sapphire crystal growth scenarios based on the KPIs we have
developed for our Value Metric comparison. The chart compares a standard 165
kilogram production boule produced in a GT ASF furnace and two standard
production boules, one 85 kilograms and one 30 kilograms, produced in KY furnaces.
There are several important points one can see when comparing the data between the
three growth scenarios. The most obvious is the number of furnaces you would have
to purchase (309 ASF furnaces vs 771 or 1,020 KY furnaces) to meet the annual
production goal of 10 million cover screens. Secondly, and even more significant, is
the operating cost difference between running a factory with 309 furnaces vs a factory
with 771 or 1,020. Operating a factory with 309 ASF furnaces will be significantly easier
and less costly on many levels than operating a factory with 2.5-3 times more KY
furnaces– lower utilities, building infrastructure and consumables to name a few.
Additionally, the value metric chart shows it would take about five to six times more
highly skilled operators to run the KY factories compared to the ASF factory. Clearly,
the value metric comparison demonstrates the advantages of ASF over KY in this
scenario, but why? What is it about the ASF equipment and growth process that so
clearly demonstrates better value to the crystal grower? The answer is uniform boule
geometry and higher yielded material from each boule.
Figure 3
A typical cover screen brick harvest pattern
from a 165 kg boule produced in an ASF
furnace. The uniformity of the boule
optimizes the amount of yielded material
which lowers the cost of manufacturing.
Why Uniform Boule Geometry Matters
The path to delivering good crystal at high volumes and at the lowest cost for cover
screen applications requires a growth methodology that can scale to produce large
diameter boules. Of the current growth methods, GT’s ASF® HEM-based architecture, is
best positioned to deliver the most uniform, large-diameter boule geometry
compared with other growth methods.
As our Value Metric chart shows, GT’s ASF sapphire growth method delivers the
highest amount of yielded material per boule or furnace. This is particularly important
if the material will be used as cover screens for smartphones. In the case of high
volume markets such as cover screens, lowering the cost of manufacturing is the most
important factor that contributes to a company’s bottom line since margins on these
products are much lower than traditional industrial sapphire markets. To meet these
price points the growth equipment must be able to produce high yielding, high
quality material at the lowest cost. Based on our extensive research and experience,
we believe that the ASF architecture provides the best overall Value Metric compared
with other methods to meet the needs of this fast-growing market. Figure 3 shows a
60mm x 125mm brick harvest pattern from a large diameter ASF boule. The uniform
geometry of the boule produces the greatest number of rectangular-shaped bricks as
shown in the diagram.
Figure 4
The lack of uniformity of a KY boule limits the
amount of material that can be harvested for
large area material such as bricks for cover
screen applications. Bubbles running
vertically through the center of the boule may
also limit the amount of material that can be
harvested for bricks.
Figure 4 shows an 85kilogram KY boule brick harvest pattern. The difference in the
amount of yielded material that can be achieved between ASF and KY becomes
obvious when we look at a similar brick harvest pattern from a typical KY boule.
Because of the irregular shape of the boule there is less material available for an
optimized brick harvest, which leaves higher amounts of scrap material and
7|P a g e
Why Your Smartphone Screen Will Be Made of ASF®-Grown Sapphire
complicates downstream cutting of bricks making it difficult to standardize uniform
length bricks.
Another contributing factor, other than the shape of the boule, is the quality of
harvestable material. One of the inherent challenges with the KY growth process is
producing a boule with minimal bubbles. Thermal patterns in the KY material during
melt and crystal growth typically concentrate bubbles towards the center of the boule
in a vertical pattern from top to bottom. Unlike LED material, which is harvested in the
C-plane axis across the width of the boule, cover screen material is harvested in the Aplane axis or the vertical orientation of the boule. A brick harvested from the center of
KY boule would more than likely have bubbles present throughout the entire length
of the brick rendering it useless for cover screen material. The bricking pattern would
have to exclude this material, which would significantly reduce the amount of yielded
material from the KY boule.
There is an obvious economic advantage in producing a larger boule and equipment
providers of all types are developing product roadmaps that indicate they will deliver
larger boules in the coming years. The challenge today for companies that are
fabricating finished products such as cover screens for mobile devices and want to
establish their market leadership now is how long will they have to wait? With ASF, the
answer is you don't. Large diameter ASF boule production is available today. You
don’t have to wait for the promise of a bigger boule announced in the headline of a
press release to become a product that can actually be delivered at volume with a
production-ready, repeatable process. ASF is already providing this today. And for
companies that want to establish a competitive advantage now and build a high
volume sapphire production operations the ASF platform is the obvious choice.
GT’s ASF® crystal growth process is known
for its ability to produce large diameter
boules of uniform geometry– a significant
factor in lowering the cost of sapphire
material for high volume applications
such as cover screens. The uniform shape
of the boule delivers higher yields of large
diameter material when compared with
KY boules. This benefits crystal producers
by lowering the cost of manufacturing, a
critical factor in delivering low cost
material for high volume markets.
Beyond the Boule – Factors Impacting Cost of Ownership
The ASF furnace and HEM crystal growth process has proven to be highly scalable in
producing ever larger boules. In 2010, when GT acquired Crystal Systems, the standard
production ASF boule was 85 kilograms. Today, in just a little over four years, the
standard production boule size has grown from 85 kilograms to 165 kilograms. GT’s
ASF product roadmap will continue along this path delivering boules well over 200
kilograms in the next few years. This is good news for customers who want to invest
today with current technology and then take advantage of the scalability of the ASF
platform to upgrade their operations as new technology becomes available in
subsequent generations.
As important as the size of the boule is to running a profitable sapphire production
business, there are other factors beyond the size of the boule that manufacturers need
to consider. There are also some significant differences in how KY and ASF furnaces
operate that will impact the overall throughput and productivity of your
manufacturing operations. While these differences don’t impact material yield or
material quality, they greatly affect productivity, throughput and overall cost of
ownership. Here are several of the most important:
8|P a g e
Why Your Smartphone Screen Will Be Made of ASF®-Grown Sapphire
Seeding – The seeding process of a KY furnace is notoriously difficult often requiring a
trained technician to spend up to as many as eight hours to set the seed properly. By
comparison, seeding an ASF furnace is greatly simplified and takes a less skilled
technician only minutes to set the seed.
Automated Growth Process – The KY growth process is a highly manual operation
requiring more highly trained operators per furnace to manage a high volume
production facility. The ASF furnace, on the other hand, is a highly automated growth
process. This greatly simplifies manufacturing operations and saves significant
amounts of overhead since it takes many fewer operators to run a high volume ASF
production facility than a KY facility.
Power Consumption – The ASF furnaces consumes 50% less power than a KY furnace
saving the operator a significant amount of money in energy usage on an annual
basis.
Hot Zones – The ASF furnace uses an inexpensive graphite hot zone that that can last
up to five years in production. KY furnaces use refractory or metal hot zones made
from expensive molybdenum or tungsten which have to be swapped out with a new
hot zone after only three or four runs. This adds unnecessary costs to consumable
expenses.
Crucibles – One of the advantages often touted by KY equipment providers is that the
cost of a crucible for a KY furnace is much less than those used in ASF furnaces. The
main reason for this is that the tungsten crucible can be used over multiple runs and
thus the cost can be amortized across the number of runs whereas the crucible in an
ASF furnace can be used only one time. GT has made significant advances in closing
the crucible cost gap between ASF and KY crucibles in the past two years by
leveraging the cost-down supply chain optimization with crucible suppliers who were
part of the Mesa, AZ project. One example of this is the recovery costs achieved by
recycling the Molybdenum crucible material back to the crucible manufacturers. This
cost-down advantage also extends to the cost of melt stock where again, optimization
with melt stock suppliers has resulted in cost-savings for this important material.
Scaling up a high volume ASF sapphire production plant entails far less risk and
significantly lower operating costs than a similarly-sized KY plant. The ASF plant will
require many fewer furnaces, fewer personnel to operate the plant which saving on
building costs, utilities and facility costs, lower capital expense and lower personnel
costs.
GT’s ASF furnace produces large diameter
boules that are optimized for the
production of sapphire cover screens. The
ASF produces 165 kilogram boules with
uniform geometry that yield more
material when compared to KY furnaces
for high volume applications that require
large diameter finished material.
ASF – The Path to Low Cost Sapphire Production
The use of sapphire material for smartphones and wearables is growing. The material
offers superior durability and scratch-resistance over the strengthened glass cover
screens found on most devices today. Early adopter market leaders, such as Huawei,
have already introduced brand extension products that use this remarkable material
as the cover screen on their Ascend P7 phone. Other phone makers are following their
lead.
Demand for large area sapphire material continues to grow. Sapphire producers
investing today in new greenfield production facilities or adding capacity to their
existing factories are looking to gain early mover market advantage in this fastgrowing segment. To take advantage of this opportunity, they must choose a sapphire
9|P a g e
Why Your Smartphone Screen Will Be Made of ASF®-Grown Sapphire
equipment supplier with a proven and scalable production furnace, and a process
capable of delivering the volume of large area material at the price points needed to
meet the product delivery demands of the brand owners and run a profitable
manufacturing operation. GT’s ASF sapphire furnaces offer customers a path forward
in delivering high volume material at costs that will allow them to successfully
compete in the market place. GT’s ASF sapphire furnace has proven to be a highly
scalable architecture that can consistently deliver large diameter boules with the best
uniform boule geometry of competing sapphire growth methodologies. Standardizing
sapphire manufacturing operations on the ASF platform will allow companies the
ability to utilize GT’s current volume production 165 kilogram technology today
knowing their investment is protected as GT introduces subsequent generations of
future ASF furnaces with the capability to produce even larger boules. For bulk crystal
growers looking to establish leadership in one of the fastest growing markets the
choice is clear. That’s why we say your next smartphone will have a cover screen made
with ASF-grown sapphire.
About the Authors
Jeff Nestel-Patt is Senior Director of Marketing at GT Advanced Technologies where he leads
the company’s branding and external communications programs in support of GT’s strategic
business initiatives.
Henry Chou is Director of ASF® Product Marketing responsible for the company’s ASF sapphire
furnace product roadmap and product marketing initiatives.
Scott Kroeger is Vice President, Business Development for GT’s Advanced Crystal Systems and
is responsible for corporate product and strategic development initiatives related to crystal
growth and supporting downstream manufacturing process technologies.
10 | P a g e
GT Advanced Technologies
243 Daniel Webster Highway
Merrimack, NH 03054
+1.603.883.5200
www.gtat.com
© 2015 GTAT Corporation. All rights reserved. ASF is a registered trademark of GTAT Corporation. Subject to change without notice.
ASFCS042015