R&D Spirits
Taking on the Challenge of Next-generation
Ultrahigh-precision Processing Technology
Akinori Shibayama
President
NTT-AT Nanofabrication Corporation

Founded in 2003, NTT-AT Nanofabrication Corporation (NTT-AT N) has the mission ofdeveloping and manufacturing leading-edge, ultrafine products using nanotechnology inheritedfrom NTT Laboratories and NTT Advanced Technology (NTT-AT). While providing the semiconductor industry with an array of products that hold the key to next-generation LSIs, the company is also intent on applying nanotechnology to fields outside semiconductors in response toclient needs. We asked President Akinori Shibayama, who has long been involved with highprecision processing technology since his days at NTT Laboratories, to tell us about current
trends in this technology and the direction of new product development.

Providing ultrafine products based on
X-ray lithography—Mr. Shibayama, could you give us an outline of
NTT-AT Nanofabrication?
Well, to begin with, the parent organization of ourcompany is NTT Advanced Technology, whose mainrole is to manage technology transfers from NTT

Laboratories. In April 2003, the Ultra High Precision
Division of NTT-AT became an affiliated company
under the name of NTT-AT Nanofabrication Corporation*. Using world-class nanotechnology cultivatedby NTT-AT, we develop, manufacture, and sell X-raymasks (Fig. 1) for lithography as our major product in*

http://www.ntt-at.co.jp/nttatn/ (in Japanese)

X-ray absorber pattern
Membrane
Glass frame
Si substrate(b) Schematic of X-ray mask(a) X-ray mask

Fig. 1. X-ray mask.

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the field of semiconductors, as well as diffraction
gratings, Fresnel lens, standard scales, and otherproducts in the field of optics. Since NTT-AT is generally associated with software for telecommunications systems, the name “NTT-AT Nanofabrication”
was chosen to make it clear that we are a manufacturing company using nanotechnology.
—What is NTT-AT Nanofabrication’s distinguishingfeature?
Its most outstanding feature would be the inheritingof lithography technology from NTT Laboratories,
which has been researching and developing this technology for some time. To give you some background
here, the last half of the 1970s saw major advances in
the integration of LSI devices, and the transferring offine circuit patterns to silicon wafers by optical means
was the mainstream technology at that time. It soon
became apparent, however, that minimum feature
dimensions would have to exceed the limits of optical
wavelengths if Moore’s Law was to be maintained.
This realization led to two new R&D trends: using
electron beams and X-rays as alternatives to opticalradiation. During my days at NTT Laboratories, myresearch dealt with both of these trends, but I was particularly involved in X-rays lithography using synchrotron orbital radiation (SOR). Unfortunately, Thislithography itself has not found widespread use in thesemiconductor field due to its high cost, but we makeuse of it in our X-ray masks that have become ourleading product.
—What are some of the technical issues surrounding
X-ray masks?
The structure of an X-ray mask is fundamentallydifferent from that of an optical mask that transfers apattern through the use of chrome on a reticle. Specifically, an X-ray mask is achieved by first placing athin film about 2 µm thick having high X-ray transmittance on silicon material and then forming a pattern on that film using tantalum film as an X-rayabsorber. In other words, the pattern cross section has
a dimension in the vertical direction. This is significantly different from a flat optical mask, and it is thisfeature that makes it possible for the first time toachieve control in the vertical direction in fineprocesses. I might add here that the fabrication of a
micro-order membrane several centimeters square is
extremely difficult in itself, and the technology forachieving this is another of our strong points.
Vol. 2 No. 7 July 2004

We are applying such specialized technologies evento applications outside the semiconductor field. One
example is Fresnel zone plates for use in X-ray
microscopes. Such a plate consists of a series of concentric rings that are used to focus X-rays. One problem here, however, is that the outermost step-likestructure of this pattern can significantly affect resolution, but we have nevertheless managed to achievea resolution of 50 nm, a world-class level. I don’t
think other companies in Japan are currently capableof this. We are also applying our thin-film technology to sample holders for use with X-ray microscopes
for our customers in biotechnology fields.

Achieving even finer processing with nextgeneration technology and promoting new
applications—What are some current trends in lithography technology development?
I previously mentioned that processing technology
using light will encounter a barrier due to wavelength
limits. Discussion on this problem continues even tothis day. The wavelength used in the 1970s was about
440 nm, while that used today is about 193 nm. The
argon laser is the most commonly used light source atpresent, and this laser is expected to be followed by
the fluorine laser. As for processes that use wavelengths beyond light, the development of exposuretechnologies using electron beams is progressing
including electron projection lithography (EPL) andlow energy e-beam proximity projection lithography(LEEPL).
—Are you developing products for electron-beamsystems?
Yes, of course. But the problem when using electron beams is that they do not pass through thin films,
in contrast to light and X-rays. An obvious solution tothis problem is to make holes in the film, but the film
itself can break down from stress if hole punching is
not performed carefully. In our products, stress isstrictly controlled and no breakdown occurs even ifholes are formed. For film with a thickness from 1 to2 µm, we have been able to make openings of sub-100nm-wide lines or holes in several centimeters square.
Using this technology, we can form holes and linesthat form an LSI device pattern in diamond or SiC film
to produce stencil masks for the lithography market.
Another new product is a fine-hole fluorine resin
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R&D Spirits

sheet (Fig. 2) that we achieve by forming an array of
uniform holes each with a diameter of about 1 µm on
perfluoroalkoxy (PFA) material using a semiconductor process. This product is receiving much attention
for use as various types of filters in the field ofbiotechnology and as electrolytic films in direct
methanol fuel cells (DMFC) to be incorporated in cell
phones and PDAs (personal digital assistants). I
should note here that controlling ion transmission inconventional macromolecule-film products is difficult due to significant dispersion in hole density anddiameter. Our product, however, is man-made andallows processing even on the sub-micrometer order,
which simplifies control. While PFA is a chemicallystable material and somewhat difficult to process, I
believe that the technical significance of this productwill be apparent as this problem is overcome. By theway, we developed this fine-hole fluorine resin sheet
through a combination of our specialized technologies.
—What direction do you expect product development
to take from here?
I would like to see it respond to the various needs
arising at sites involved with the development of leading-edge technology. The nanoimprint mold (Fig. 3)
is one example of a new product that falls into thiscategory. This is a kind of a stamp for producing

Region with fine holes

nano-order patterns at low cost. At NTT-AT Nanofabrication, we fabricate patterns of various shapes up toseveral tens of nanometers in size in accordance withcustomers’ designs. What makes our molds stand out
is that processing can be performed in the depth
direction and that mold material can be chosen fromfour types, namely, silicon carbide (SiC), quartz, silicon, and tantalum. By the way, nanoprinting equipment is still in the research stage—technology andsystems are far from mature. And as can be expected,
a variety of requests are being made concerning materials. Under these circumstances, our policy is to satisfy these requests as far as possible. At the sametime, we don’t intend to limit our work to simply
responding to customer needs. We also plan to present our customers with our own proposals.

Having a personal impact on both R&D andbusiness—Mr. Shibayama, what kind of R&D have you been
involved with up to now?
Well, as a university student, I researched high-frequency devices using indium-phosphorus semiconductors. At that time, gallium arsenide was a common
topic of research, but even crystals of indium phosphorus could not be made then without difficulty, soI think I was involved in advanced research of a sort.

PFA film (10 µm thick)Fine holes
1.4 µm

PFA film(a) Outside of the film supported by a frame(b) SEM photographFig. 2. PFA film with artificially formed holes.

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R&D Spirits(250-nm pitch)
0.5 µm100-nm trench on quartz

SiC dots(100-nm pitch)

0.2 µm200-nm line-and-space tantalum patterns(400-nm pitch)

20-nm Si nanolines(60-nm pitch)

Fig. 3. Nanoimprint molds.

But after entering the research laboratories of Nippon Telegraph and Telephone Public Corporation, I
took up research themes completely different fromthose I had pursued in my university days. The firstwas the development of electron-beam exposure
equipment, which I was engaged in for about eight
years beginning in 1975. This work included joint
research with manufacturers that contributed to thedevelopment of practical equipments.
Then, in 1985, I became a member of the SOR lithography project that I mentioned earlier. I was mainly in charge of the SOR ring, which is used to extract
wavelengths for exposure purposes from light radiated when an electron orbit bends. This equipment wastraditionally large because it used electromagnets
whose relatively weak magnetic fields cannot easily
bend electron orbits. Consequently, with the aim ofconstructing smaller equipment, I took on the development of a superconducting SOR ring. At that time,
though, it was thought that a practical ring-type
Vol. 2 No. 7 July 2004

superconducting magnet was not feasible, and a number of respected researchers from other research institutions were known to have unanimously said “stopuseless research.” At the same time, research basedon a similar concept was also being conducted in Germany, and we became strongly aware of each other’sdirection. The project became very exciting as aresult. In the end, the German group, though laterbearing fruit in the United Kingdom, was not successful, and our team became, in 1988, the firstresearch group in the world to successfully develop asuperconducting ring. For this, we received a Presidential Commendation from NTT.
I also conducted joint research from 1997 to 2000
with the Association of Super Advanced Electronics
Technologies (ASET), an organization associatedwith the Ministry of International Trade and Industry(currently the Ministry of Economy, Trade and Industry). I then became involved in management andmoved to NTT-AT in 2001, becoming president of9

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NTT-AT Nanofabrication upon its founding last year.
—What do you consider your role to be at NTT-AT
Nanofabrication?
In one word, I would say “business,” but with thatbeing said, I must tell you that only a small percentage of my activities involves approaching customers
directly. That is because our products and technologies are introduced through Web sites and journal
articles, or even exhibitions, which are often followed
up by inquiries or consultations where business really begins. Many of our customers are scientific or
research institutions, and most products are made toorder. In fact, manufacturing a single product for acustomer is not unusual. At the same time, we are a
private enterprise that must keep profits in mind if weare to survive, and this is where I step in. My job is tofind good matches between our technologies and customer needs.
Our business area, moreover, is one of advanced,
specialized technologies, and there are many cases inwhich we ourselves take a second look at technology
we have developed and say “couldn’t we also apply
this to that field?” A good example of this would be
the fine-hole fluorine resin sheet that I mentioned earlier, which we found could be applied to fuel cells.
This field is completely outside my area of expertise,
but after being approached about this possibility andinvestigating it thoroughly, I realized that our technology and facilities could make it work. This is why
our policy is to accept customer requests as far as possible. In accepting such work, the most important criterion, I believe, is whether our technology can bemade good use of and whether we can discover aproduct market that cannot be easily entered by othercompanies.
—Is there anything that you have kept in mind in yourwork up to now?
Yes, that would be the need to ascertain what kindof impact your work will have. Let me give you anexample. When attempting to improve the performance of some type of equipment, it might be possible to achieve the level desired by combining thatequipment with existing technology. If that were thecase, I think that the technology should be used—
there’s no reason to create new technology and systems specifically for that purpose. Yet, in many cases,
existing technology is not sufficient to get what youneed. In that situation, we would then spend the10money and take the time needed to develop new technology. However, achieving just a minor improvement in performance does not make for interesting
research. If we are going to go to the trouble of developing new technology, then it better have a majoreffect. For this reason, I always try to determine whatkind of impact one thing will have on another. This
makes up most of my work, not only in R&D but also
in business matters.

Applying the achievements ofNTT Laboratories—Mr. Shibayama, what is the future outlook for NTTAT Nanofabrication?
First, let me point out that the Ultra High Precision
Division of NTT-AT was set up in 1992 and NTT-AT
Nanofabrication was founded in 2003. In otherwords, it took about ten years for one division ofNTT-AT to grow and develop before becoming anindependent company. How the company will continue to develop over the next ten years is a matter ofvital importance. The most desirable approach for thecompany’s business is to become a user and incubator of NTT technology. To this end, my role in the
coming years will be to construct a solid stage for thisprocess. By the way, of the 40 employees making up
our staff, about 30 are young up-and-coming people.
My sincere hope is that, in ten years time, they will
say “we’re glad that we came to work at NTT-AT
Nanofabrication.” As for myself, I have not given
much thought to where I might be ten years down theroad, but I know that I would like to be facilitating theuse of research results from NTT Laboratories insome way, shape, or form.
—How do you view the relationship between NTT
Laboratories and NTT-AT Nanofabrication?
Our technologies are not ones that can be created ina single day. For example, X-ray mask technology
has been researched at NTT Laboratories from various angles since the 1970s. But it was only after several decades of results that this technology could beturned into a business. And it is for this reason that Ibelieve this relationship cannot be a one-sided affair.
Even superior research will not bear much fruit
unless it can see the light of day in the outside world.
This is where NTT-AT Nanofabrication comes in.
Finding the most effective way to apply research
results to the real world is where we can demonstrate
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our abilities.
—Do you have any suggestions for NTT Laboratories?
Looking back at the history of NTT Laboratories, I
would say that they have been through several phases. First, there was the period up until the 1960s or soduring which they began to accumulate technology
starting from nothing. The next period was the time
up to NTT privatization when they endeavored to bea driving force in the industry through telecommunications technology. The technical level of surrounding companies, however, has since risen significantly.
The direction of NTT itself, moreover, has beenchanging. I think the reason for this is that NTT Laboratories is now anxious for results and makes toomuch use of outside technology. The feeling is thatexisting technology only covers part of what it takes
to get a new product out the door. In my opinion,though, this does not make for smooth product development and also hinders the full use of existing technology. I am also afraid that NTT’s traditional
research scheme connecting basic research withproduct development and application will be lost as aresult. Even if 100% of existing technology is notnecessary, it is vitally important, I think, that most of
the key technologies in question are those that belong
to us, especially in the case of hardware. Of course,
achieving fast results is often essential today, but it isalso important that the overall picture not be overlooked. Though the present period is a difficult one, I
would hope that the positive elements of NTT thathave been built up over its long history are not lost.
—Mr. Shibayama, could you conclude with a message for young researchers?
Yes, certainly. I believe it is important and necessary that a synergistic effect be produced between theyoung researchers of NTT Laboratories and thealumni of those laboratories including myself whoVol. 2 No. 7 July 2004

are now working at group companies. The LSI technology that we have come to develop is of course
important, but the times are changing. Today, it isimperative that we give birth to the things that this age
demands. I would therefore like to ask all young
researchers to do more “dreaming.” I would like to
see them engage in more talk like “that would beamazing” or “I would love to make that possible.”
Such talk should lead to more talk like “we can dothat in this way—let’s give it a try.” If better interaction like this can take place, I think even greater
strength can be generated in the NTT Group leadingto a scheme whereby researchers play a more activerole in the business world by making optimal use ofresearch results.

Interviewee profile■ Career highlights
1975 Completed the graduate program at Tokyo
Institute of Technology and entered theMusashino Electrical Communications Laboratory of Nippon Telegraph and Telephone
Public Corporation.
1990 Senior research engineer at NTT LSI Laboratories.
1998 Research manager at NTT Telecommunication
Energy Laboratories.
2001 Director of the Precision Technology Divisionin the Leading-Edge Key Technology Business
Headquarters of NTT Advanced Technology.
2003 President and C.E.O of NTT-AT Nanofabrication Corporation.
■ Major awards
1989 Presidential Commendation from NTT for“Research of Superconducting SOR Ring.”
1994 MNE ’94 Best Poster Award

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