TECH Meets BUSINESS

Diamond is the best material.

I heard that you were engaged in research at a materials manufacturer before you joined AIST. What kind of work did you do there?

A possibility to scale up. This is why we started our business.

-- You decided to start a business during a recession. Was it because of your expectation and trust in that technology?

Fujimori:

Yes, it was because we had diamond materials. Diamond is a very hard substance, and this is because the distance between neighboring carbon atoms that constitute diamond is short and the bond between those atoms is strong. This characteristic is linked to its properties of high thermal conductivity and high propagation of the speed of sound. The reason why diamond is used for expensive tweeters is because of these properties.

-- It attracts a great deal of attention as a semiconductor material, doesn’t it?

Fujimori:

Please imagine the periodic table in chemistry. Carbon (C) is right above silicon (Si), which is a semiconductor material. These two elements are in the same group, and they have similar properties. Diamond is an insulator, which does not conduct electricity, and it is possible to turn this insulator into a semiconductor by adding impurities. Diamond has properties superior to those of silicon, such as thermal conductivity and high voltage endurance.

-- Other than its use as a semiconductor, are there any other possible uses?

Fujimori:

In the first place, it is rare to find a substance with multiple properties that are more excellent than the properties of other substances. In most substances, a certain property may be excellent, but other properties are not. In contrast, diamond has many excellent properties such as hardness, thermal conductivity, insulation, and optical properties. Human beings have used only a few advantages of diamond. Increasing our usage thereof would enable us to consider ways in which to use it such that existing concepts could be changed.

-- Speaking of diamond, we can’t help imagining a gem, but many synthetic diamonds are produced for industrial use. How is diamond produced?

Fujimori:

The present mainstream methods are a high-pressure, high-temperature synthesis method, and a chemical vapor deposition method. The former of these methods involves subjecting material carbon atoms to high pressures and high temperatures similar to the environment in which diamond is produced in nature. On the other hand, what we have chosen is the chemical vapor deposition method, and this is a method in which diamond is produced from a carbon-containing gas. We can produce diamond as though “frost were formed.”

-- What do you mean by as though frost were formed?

Fujimori:

In winter, dew condensation is often seen on window glass. The principle is the same as that. Actually, this dew condensation “grow” from the surface of glass. Under certain conditions, moisture that cannot dissolve any further in air will "grow" from the glass surface as drop of water. We use this principle in a similar way, using a carbon-containing gas, such as methane gas. In the chemical vapor deposition method, the gas pressure is about 0.1 atmosphere, which is lower than atmospheric pressure, and the temperature is about 1000 degrees. Of course, there are various other conditions, but at this point, we can say that this method is easier than the high-pressure, high-temperature synthesis method.

-- Then, you “peel off” the diamond that is produced, and you create a planar diamond, correct?

Fujimori:

We use technology called “electrochemical etching,” which was developed at AIST. This method enables us to directly produce a planar diamond without going through granular diamonds. If we have a seed crystal, we can duplicate it to form a planar diamond with the same size.

-- Does this mean that you are only able to produce diamond with the same size as the seed crystal?

Fujimori:

No, we can increase the size by positioning the produced planar diamonds vertically and horizontally and using them as a seed crystal. I remember that I recognized a promising business opportunity at this point. If we can produce a large single crystal, the range of application as material becomes large. For example, to use it as semiconductor wafers, the size needs to be about 2 inches. Right now, it is around 1 square inch, but we are conducting research and development so that we can produce larger ones, such as 2 and 3 square inches.

Thinking of Japanese industry, I consider the manufacturing industry to be important after all.

-- I heard that commercialization was triggered when you realized a way to produce planar diamond in larger sizes.

Fujimori:

Yes, the chemical vapor deposition method was already an established technique when we started our business. As you know, we thought that we could do well, when we saw a prospect to increase the size as a result of technological development at The Diamond Research Center in AIST. It was around the year 2007.

-- Could you tell me to which fields it will be applied in future?

Fujimori:

For material, it is essential to collaborate with researchers of devices in which the material will eventually be used. For example, when a material is applied to semiconductor wafers, we will ask researchers to consider in which devices the material could be used if we were able to produce the material at a size of 2 square inches, also what would be possible if we were able to obtain an even larger size such as 3 and 4 square inches. Then, the next thing we will probably encounter is the problem of cost. Since the material will be sold as a product, manufacturers would like to manufacture it in a preferred price range.

-- Could you tell me about commercialized products?

Fujimori:

Among the products we have launched since our company was founded, there are cutting tools. For example, when aluminum is chamfered, it is not possible to obtain a high-gloss surface without using cutting tools made of a sharp material such as a single crystal of diamond. Mostly, the sizes of diamond parts used in the blades of diamond cutters are small, but if a large planar blade is used, we can produce parts with accuracy that has been impossible to achieve so far. Actually, there are cases, for which the required accuracy is hard to achieve when a new product is made, and tools made of a single crystal of diamond are needed, and then, a large-sized single crystal produced in our company is used.

-- Demand for a material arises only if there is a request from the application side, doesn’t it?

Fujimori:

That is also hard. Simply because we have the ability to produce a large diamond, it does not necessarily mean that a business opportunity exists. I think that the business only pays when an application is found for a product. It takes time until this occurs. We are asked whether we would be able to survive until then. Right now, there are various inquiries from manufacturers of tools and heat sinks, and from research institutes of diamond devices, and we are asked how we respond to them.

-- Lastly, tell me about the future prospects of EDP Corporation.

Fujimori:

To launch and run a start-up company in the materials field, we need a lot of time, the cost of developing the product, and capital for purchasing equipment, but I think that what we need to do in Japan from now on is to focus on the manufacturing business, of course. This is what I have been thinking since I started this company. That is why I would like to continue doing this business in Japan. Although the size of the company may not be very large, I would like to make our company a major player in diamond manufacturers within several years in the future.

* The contents of this article are based on information as of January 10th, 2014.