Late at night, Dr. Zhai Hao, a senior engineer at the Suzhou Institute of Nano-tech and Nano-bionics (SINANO) of the Chinese Academy of Sciences, steps out of the super-clean laboratory of the nano-processing platform. His work is not over yet, because he still needs to test the chip he just finished making in the clean room on the optical platform upstairs.
Dr. Zhai is one of the scientists and engineers who work quietly on the innovative forefront of micro- and nano-manufacturing. They scrutinize the minute details while gazing up at the starry sky. The more detailed the observation of the structure under the microscope, the clearer the blueprint for the future "sky of microchips" will be.
Zhai Hao's granduncle worked at the Institute of Acoustics, Chinese Academy of Sciences during his youth. When Zhai Hao was still a primary school student, his granduncle often took him to visit his workplace and repeatedly told him, "Anyone or anything can deceive you, but the laws of physics cannot. Only by understanding, mastering, and applying them more thoroughly than others can you avoid relying on foreign powers and being sanctioned by others."
His granduncle also enjoyed taking Zhai Hao to visit the planetarium. The spectrums of stars in the sky contain a wealth of information and are the best testing ground for the laws of physics. Among the many physical constants, Zhai Hao's favorite was the fine-structure constant (1/137), as it holds the ultimate mysteries of our universe.
Due to his early exposure to science, Zhai Hao independently studied calculus and general physics during middle school, which are university courses, and won awards in national physics and chemistry competitions several times. In 2006, he entered the Chemistry Ascent Program at Central South University. Later, he was recommended for graduate studies without an entrance exam and joined the Nano-Fabrication Platform of the Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO) after graduation. Under the guidance of the platform's director, Zhai Hao began exploring the principles, fabrication, and testing of chip-level atomic devices.
However, Zhai Hao, who was initially full of confidence, encountered many setbacks in the laboratory. To improve his work, he returned home after work to independently study basic knowledge such as semiconductor physics, microelectronics technology, and atomic optics. Despite his efforts, his technical skills improved very slowly.
"Practice makes perfect." To quickly improve his technical skills, Zhai Hao spent a lot of time in the laboratory and built a rapport with the technicians. He asked questions whenever he didn't understand something, as if he had returned to his postgraduate days. While laying a solid foundation, Zhai Hao's research gradually improved, and he once again saw 1/137 in the atomic fine-structure spectrum of the atomic cell he prepared. The end of the microcosm was the starry sky that fascinated him.
Chip-level atomic devices control and detect the quantum states of alkali metal atoms in the atomic cell, using an optical pump and probe generated by a laser. They can achieve functions such as high-precision weak magnetic field detection and time-frequency signal output. They are widely used in positioning, navigation, surveying, and communication technologies and are key components for national security systems.
The United States has consistently been at the forefront of the world in the field of key fabrication technologies for chip-level atomic devices. Due to technological blockades and a lack of first-hand design information, relevant research and development in China has encountered significant challenges.
To overcome these technical difficulties, Zhai Hao, with the support of the institute, began working on the challenging technical development of atomic cell chips, the core components of atomic devices, in 2016. He relied on the lithography and plasma etching equipment of the Nano-Fabrication Platform and his understanding of basic theories in atomic optics and physical chemistry.
Initially, the key fabrication processes for atomic devices were incompatible with existing semiconductor processes, and no dedicated equipment was available. Furthermore, the experimental materials, such as purified isotopes, were very expensive, costing 100,000 CNY per gram, making large-scale use financially unfeasible. These factors severely hindered the progress of the research work.
The design of the experimental scheme had to be discussed repeatedly and carefully, and the experimental operation had to be calm and steady. It was crucial to extract useful information from each valuable experiment and analyze as many possible factors as possible from each failure. To conserve as much of the expensive experimental materials as possible, Zhai Hao practiced the fine movements of his wrist and fingers to improve the stability of his operation, so much so that his colleagues joked that his right hand was as steady as an analytical balance.
With his determination to "not miss any detail or overlook any phenomenon," after two years of arduous research, countless sleepless nights in the ultra-clean laboratory, and countless failures, Zhai Hao finally developed a reliable process scheme and solved the problem of isotope atomic manipulation. He successfully fabricated the first single-cavity MEMS atomic cell.
This research result provided strong support for several atomic device projects in the institute. After further improvement and optimization, the engineering manufacturing of atomic cells was achieved. This technology not only obtained four national invention patents but also resulted in 8 million CNY of technology transfer and application, which has significantly contributed to the development of related industries.
Through his participation in numerous national and provincial research projects and his own tireless efforts over many years, Zhai Hao has honed his exquisite micro- and nanofabrication skills and has become a "craftsman" who supports the major scientific research efforts of the institute.
Admirably, Zhai Hao is not only a skilled "craftsman" but also a dedicated "gardener" who nurtures talents. While diligently completing national scientific research tasks, he also generously shares the micro- and nanofabrication technologies he has mastered over the years to cultivate high-skilled personnel in the field for the nation.
Over the years, he has participated in teaching Suzhou Industrial Park's "High-skilled Talent Training Program in Nanotechnologies" on electron beam processes, photolithography, and circuit fundamentals. He has also participated in the preparation of questions, training, judging, and paper review for the Suzhou Industrial Park High-Skills Competition for four consecutive years. By focusing on key areas, he has effectively improved the professional and technical level of personnel in multiple units in the park.
In addition to teaching technical skills in his classes, Zhai Hao also emphasizes the inheritance and promotion of scientific spirit. He often uses stories about scientists and engineers around him to encourage his students to live up to the mission of the times, focus on national development, and contribute to the achievement of a high level of scientific and technological self-reliance and self-improvement.
"The excellence of one person is not true excellence. The excellence of a group of people is true excellence." This is the philosophy that Zhai Hao has always adhered to. Now, after 11 years at SINANO, he remains dedicated to his craft, working diligently in the frontier field of micro- and nano-intelligent manufacturing and fighting alongside other researchers to seize the commanding heights of science and technology. From Suzhou Institute of Nano-Tech and Nano-Bionics, CAS.
Science and Technology Daily (2024-03-20 Page 4, Comprehensive)
