Wang Shusheng: Development History of CVD Diamond Project of Laser Institute of Hebei Academy of Sciences

**Abstract** Since 1991, the CVD diamond project has experienced over two decades of development, marked by continuous improvement and evolution. Though it may seem like just a few years in the grand scheme of things, the journey has been long and filled with challenges. Looking ahead, the project is still in its early stages—like a child who has just learned to walk. Reflecting on the past, we have gathered valuable lessons and are eager to share them with all of you. **First, Seize the Opportunity, Meet the Challenge, and Take Part in the National "863" Plan** There are multiple methods for synthesizing synthetic diamonds, but only a few are used for chemical vapor deposition (CVD) diamond films. The method we adopted was DC plasma jet chemical vapor deposition (DC-PJCVD). In the early 1990s, this technology was virtually unknown in China. In 1993, Dr. Li Huiqi from Beijing University of Science and Technology came across an advertisement for a plasma cutting machine and saw potential in the technology. He traveled to Shijiazhuang, hoping to adapt the machine into a system for producing diamond films using DC plasma jet CVD. A cooperation agreement was signed just two days after the initial contact—marking the official start of our diamond project. The researchers at our institute had no prior experience in this field, but they were determined. With some basic knowledge of plasma cutting technology and limited foreign literature, they began working day and night. After nearly a year of effort, the first DC plasma spray CVD diamond film equipment was successfully assembled, and the first 30 mm diameter diamond film was produced. The successful development of the plasma torch became a key breakthrough, and it earned a national invention patent in 1998. Additionally, innovations in gas circulation and balance significantly reduced gas consumption, making the device more efficient and practical than similar foreign systems. This equipment was fully developed and owned by the Laser Research Institute of the Hebei Academy of Sciences, marking the beginning of a new era. In August 1994, a demonstration meeting was held in Beijing to showcase the “Diamond Film Preparation Key Equipment.” The Hefei Plasma Research Institute of the Chinese Academy of Sciences had already set the direction. At a critical moment, Li Guohua, director of our diamond project, stood up and presented the research progress and achievements of the previous year. His earnest speech and solid work impressed the expert group, leading to the decision that the Hebei Academy of Sciences’ Laser Research Institute would serve as the pre-research unit for the project. On May 6, 1995, the expert group arrived for inspection. Just the day before, the device failed due to a blockage in the gas path. The team worked through the night to fix the problem, and by morning, everything was back on track. The experts were highly satisfied, and the project was officially awarded the “863” program, making the Hebei Academy of Sciences the first in Hebei Province to undertake such a national-level initiative. With support from the program, the team developed a 100 kW film-making equipment and successfully produced a 100 mm diameter diamond film within six months. By 2006, a group of six academicians, including Lin Lanying and Shi Changxu, visited the site and conducted a thorough evaluation. They praised the achievement, stating that the Hebei Academy of Sciences had become the third country after the U.S. to independently design and manufacture high-power DC plasma jet CVD equipment. This not only provided an alternative industrial method for diamond tools and heat sinks but also laid the foundation for future optical applications. Thanks to the “863” program, the project gained international recognition and became a leader in the domestic industry. Over the years, the project received more than 600 million yuan in funding from the state, province, and academy. It also won six provincial and ministerial-level science and technology awards, including the first prize in Hebei Province’s Science and Technology Progress Award in 1997. **Second, Perseverance, Hard Work, and Embark on the Road to Industrialization** Scientific research is never easy, and industrialization is even more challenging. The idea of industrialization was mentioned in a cooperation agreement with North University of Science and Technology in the summer of 1996. After winning the Provincial Science and Technology Progress Award in 1997, the team aimed to achieve two forms of industrialization: one for the equipment and one for the diamond film products. In 1999, the first batch of diamond films hit the market, initially targeting wire drawing dies. However, the product faced quality issues, such as low density and rough surfaces, which led to customer returns. Through analysis, the team identified the root cause and made necessary adjustments, improving the process and the performance of the diamond films. In 2000, the Laser Research Institute was transformed into a technology-based enterprise, bringing new challenges. Funding was scarce, and many team members left. Despite these difficulties, the core team remained committed, driven by their belief in the project's potential. Through selling equipment, securing research funding, and utilizing revenue from plasma cutting machines, the team managed to sustain operations and gradually overcome the obstacles. Although the market for equipment was limited, it was essential for survival. Meanwhile, research grants, though modest, played a crucial role during tough times. The team focused on the market, addressing customer feedback and refining the production process. By 2003, the application of wire drawing cores proved successful, outperforming traditional diamond materials. With continued process optimization, the team improved yield, quality, and competitiveness. In 2005, sales of diamond films helped maintain the lab’s operations, while the equipment business slowed down. 2006 marked a turning point, with the introduction of the world’s first transparent mechanical-grade CVD diamond. That same year, the team expanded internationally, gaining attention in Europe and America for its cost-effective, high-performance products. Today, the company offers a wide range of diamond films tailored for different applications: tool-grade films for precision machining, thermal-grade films for high-power LEDs, optical-grade films for laser windows, and acoustic-grade films for high-fidelity speakers. The company now produces various sizes of wire drawing cores, dresser blanks, heat sink films, and optical films, enjoying a strong reputation both domestically and internationally. **Third, Transform the Development Model, Give Wings to Industry Development** In 2009, Hebei Presman Diamond Technology Co., Ltd. was established. With the support of leadership, the company was formed around the original diamond project team, aiming to implement a modern and efficient management system to ensure sustainable growth. After more than a decade of hard work, the company faced the global financial crisis but still managed to grow by 30% annually. Focused on creating top-tier products and managing efficiently, the company continues to develop large-grain gem-quality diamonds and optical-grade films for high-end applications, paving the way for the future of diamond technology.

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