Corporation began to develop ruling engines in 1961, and in
that year Mr. Yoshida participated in its development project
as an engineer in his fifth year at the company. Ruling engines
are precision machines used for making diffraction gratings.
They can draw 1,000 to 1,500 parallel lines per millimeter
on the surfaces of 10cm x 10cm flat glass plates using diamond
cutters. Through the ruling engine development project, which
lasted for about 10 years, Nikon engineers developed a very
accurate laser interferometer-based XY stage positioning mechanism
and peripheral technologies. These technologies contributed
greatly to Nikon's development of steppers, of which the company
has become the world's number one manufacturer.
Mr. Yoshida says, "I tried very seriously
to find any possible application of these technologies because
it had taken the company 10 years to develop them." Fortunately,
the Japanese semiconductor industry had just entered its growth
stage at that time. Nikon developed mask coordinate measuring
machines for semiconductor manufacturers in the early 1970s,
making good use of these technologies. The machines were the
world's first instruments that could measure the positions
of masks with a precision of 100nm.
Mr. Yoshida says, "Nikon used to make special custom-made
ruling engines and astronomical telescopes. But the company
received repeat orders for its mask coordinate measuring machines
from customers for the first time. This convinced me that
semiconductor manufacturing- related machines would provide
a good business opportunity for the company. So I started
my career in the semiconductor-related industry."
When he started his career in this industry, semiconductors
were being produced using the contact printing microlithography
system, in which masks are placed directly on wafers to imprint
microscopic circuitry patterns. Imprinting finer circuitry
patterns on wafers requires the reduction of mask patterns
through optical lenses. Mr. Yoshida thought reduced patterns
could be imprinted accurately on wafers by moving the wafers
very accurately, if his company were to make use of its mask
coordinate measurement technology coupled with its high-resolution
lenses. "But," he says, "no one in the industry
considered it possible to develop such steppers, arguing that
the basic concept of steppers at that time could not satisfy
the needs of semiconductor manufacturers in terms of productivity."
In 1976, Nikon was asked to develop steppers
by an organization that had conducted a VLSI R&D project.
The organization was set up to carry out Japan's first national
semiconductor development project.
Mr. Yoshida says, "We delivered our first stepper to
the organization in 1978, and a commercial version was launched
in 1981. Initially, our model was able to imprint circuit
patterns with a line width of 1 micrometer using a 1/10 reduction
projection system. After the first machine was introduced,
a novel 1/5 reduction projection system, which can also imprint
lines that are 1 micrometer wide, was released. This helped
semiconductor device maker improve their productivity fourfold,
and this is why Nikon has become the world's number one stepper
The key to the success of his company was
setting clear project targets and thorough discussion among
project members. Mr. Yoshida says, "I think setting clear
targets in application research is very important, and this
can be applied to the nanotechnology area as well."
When Nikon started developing steppers, most of the researchers
and engineers were young. They discussed issues very frankly,
and their honest discussions sometimes caused arguments. "I
believe that how deeply staff who are involved in a project
can discuss issues determines whether the project team can
make most of its integrated ability," says Mr. Yoshida.
These, for him, are the necessary factors for a successful
project. As a project leader, he always wants to encourage
participants to generate new ideas.
(Interviewer: Kuniko Ishiguro, Cosmopia Inc.)
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