May 13, 2022

Success in mass production technology for ultra-pure 2 inch diamond slices; should stimulate the realization of quantum computing

Adamant Namiki Precision Jewel Co. Ltd. (Adachi-ku Tokyo; President and CEO Riyako Namiki) has successfully developed a mass production method for ultra-pure 2-inch diamond wafers. This ultra-pure diamond contains no more than 3 ppb (parts per billion) of nitrogen atoms, as required for quantum applications, such as quantum computers*1, quantum memory*2 and quantum sensing devices . The newly developed diamond wafer has a diameter of 2 inches (about 55mm), much larger than the 4mm × 4mm crystal currently available. This new technology is expected to propel the advancement of quantum applications. Adamant Namiki plans to bring the product to market in 2023.

On September 9, 2021, Adamant Namiki Precision Jewel Co., Ltd., in collaboration with Saga University, successfully produced a 2-inch diameter wafer (trade name: KENZAN DiamondTM) using a flow-through method. single steps*3. However, this method used nitrogen gas to achieve a high growth rate suitable for mass production, but left several ppm (parts per million) of nitrogen impurities, which would affect quantum applications. Since then, Adamant Namiki has improved its production method to obtain its ultra-pure 2-inch diamond with no more than 3 ppb of nitrogen, making it suitable for quantum applications.

In contrast, commercially available ultra-pure diamond wafers that contain no more than 3 ppb nitrogen are only 4 mm × 4 mm. Although this wafer size can be used for basic research, it is too small for practical applications.

Adamant Namiki has developed a new mass production technology for 2 inch diamond slices that nearly eliminates nitrogen contamination during the crystal growth process, resulting in ultra-high purity. A 2-inch slice of diamond theoretically offers enough quantum memory to record 1 billion Blu-ray discs. This is equivalent to all the mobile data distributed worldwide in a day.

Fig. 2 inch (55mm diameter) ultra-pure diamond wafer and 4mm × 4mm crystal currently available

Adamant Namiki plans to develop peripheral technology, including polishing technology, for commercial release in 2023. This should dramatically accelerate research into quantum devices using large-diameter diamond wafers.

Announcement of search results:
International Conference on Compound Semiconductor Manufacturing Technology 2022 May 10, 2022

Two inch high quality diamond heteroepitaxial growth on sapphire for electrical appliances »

*1 quantum computer
A conventional computer calculates using 2 digits, “0” and “1”. In contrast, a quantum computer

would use the principles of quantum mechanics. A quantum computer would significantly shorten computing time compared to a conventional computer, enabling major advances in many fields. Competition for development is thus accelerating worldwide.

*2 Quantum Memory

A type of memory for quantum computers. A diamond crystal defect called NV-center in principle shows high performance for quantum memory. The NV center consists of a nitrogen atom and a corresponding vacancy in the diamond lattice. This NV center could form a tiny magnetic force and function as a quantum memory at the atomic level. Although research is being conducted around the world using 4mm square diamond crystals, it is difficult to achieve practical applications without larger wafers.

In addition to diamond, it is also possible to obtain electron spin in other materials, but the direction of their spin cannot be stabilized at room temperature. Apparently, only diamond can achieve room-temperature electron spin that is reliable enough for industrial applications, such as high-sensitivity high spatial resonance magnetic sensors, quantum computing, and biomarker sensors. For applications requiring high resolution and high sensitivity, a diamond crystal with few impurities is needed, such as the 2-inch diamond just developed by Adamant Namiki.

*3-step growth method
Tilting the crystal orientation of the sapphire substrate by several degrees relative to the A-plane allows the creation of an atomic-level stepped structure for diamond growth. The crystal grows (flows) in a lateral direction through the steps, greatly reducing heteroepitaxial stress and improving crystal quality. (

About Adamant Namiki Precision Jewel Co., Ltd.

Created: August 28, 1953.
Number of employees: 550 (as of January 1, 2022).

Founded in 1939. Started by manufacturing ball bearings for electric meters.

With jewelry processing technology (cutting, grinding and polishing) as the core technology, the company has continued to develop its advanced technology to create a variety of products. It currently manufactures and sells precision jewelry parts, coreless DC motors, fiber optic components and medical devices.

Adamant Namiki Precision Jewel Co., Ltd.

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