The purest diamonds, containing only carbon, are extremely rare in nature, just 2 percent of 100 diamonds mined. The rest of the natural diamonds contain impurities, mainly nitrogen, which complicates their use in electronics.
Russian specialists succeeded in improving the technology enabling the creation of conditions similar to natural ones to grow the purest and largest nitrogen-free diamonds (rare Type IIa).
In 2022, engineers of the innovative Diatek company grew Type IIa diamond crystals weighing almost 60 carats. Today, a new record of a 92.23-carat synthetic diamond grown was set at the company’s new production site in the town of Kimry, the Tver Region. A diamond crystal weighing 92.23 carats, with its linear dimensions 28x26x15 mm, was obtained during a 530-hour cultivation process.
The Diatek factory is the largest in Europe. It specializes in growing ultra-pure diamonds using the HPHT method. The use of the most advanced equipment and the company’s focus on improving the technology for growing both mono- and polycrystals used in various industries made it possible to set a new record.
Diatek’s Director General Eduard Gorodetsky noted, “In addition to developing the crystal growing technology aimed at fostering Russia’s technological sovereignty, the specialists of our group of companies work actively in doping grown diamonds. This work opens up unique opportunities for Russia to develop diamond-based electronics, which is increasingly in demand in the world.”
As for the record-breaking 92-carat crystal, the fate of the diamond, according to Gorodetsky, is expected to fundamentally differ from that of its predecessors that were cut and polished to be used for jewelry manufacturing. The results of the crystal analysis and its characteristics showed that it is possible to obtain a multi-sector monocrystalline plate of a record size or several single-sector plates of a smaller size from this diamond. It is worth noting that there are very few diamond plates of such impressive sizes in the world and they are in great demand in the market. The cost of such a plate can exceed tens of thousands of dollars. According to Diatek’s CEO, the manufacturing of a single-crystal plate of such a big size will make it possible to clone the parent substrate in CVD reactors jointly with leading Russian research institutes.
“Particularly large single-crystal plates obtained by the CVD method will make it possible to conduct a number of commercially important studies, including testing the complete cycle of manufacturing semiconductor devices on single-crystal diamond substrates. The technology for the stable manufacturing of large-size single-crystal diamond plates will allow us to quickly take a leading position in the world,” Gorodetsky said.
According to industry experts, diamond plates with such characteristics will allow Russia to study the possible use of large diamond windows for different types of lasers and X-ray optics. Moreover, production of large single-crystal plates opens up the possibility of growing single-crystal substrates of 50-100 mm in diameter with mosaic growth using a CVD process. Substrates of this size are standard in the electronics industry. All technological systems used in the microelectronics industry are designed for using the substrates of standard sizes. Therefore, the production of diamond substrates greater than 2 inches will allow the manufacturing of device structures on their basis, including epitaxial structures of silicon carbide (SiC) and gallium nitride (GaN) used in microwave transistors and power electronics, without the significant restructuring of the production process. Such transistors are currently the cutting edge of the world developments in electronics.
Galina Semyonova, Editor in Chief of the Russian Bureau, Rough&Polished
