In the early morning of April 17, 2018, the U.S. Department of Commerce announced that it would ban U.S. companies from selling parts, goods, software and technology to ZTE for seven years, until March 13, 2025. As soon as the news came out, it caused an uproar in our country. From the Chinese government to ordinary people, they were deeply aware that it was urgent for China to design and manufacture its own chips. A chip the size of a fingernail has now become an important bargaining chip in global corporate competition and technology competition.
In the same year, Ye Mao, who was still studying for a doctoral degree at the University of Michigan in the United States, began to independently take charge of a graduate course on the recommendation of his supervisor, focusing on chip integrated nano-manufacturing technology. Looking at the students of different skin colors and different countries in the classroom, Ye Mao, who was standing on the podium to teach the chip integrated nano-manufacturing technology, felt increasingly uncomfortable when thinking about the uproarious incident of Chinese chips being "stuck" by the United States. In the icy and snowy night of Michigan, an idea popped into his head: "Maybe I can do something."
As this idea emerged more and more, Ye Mao began to prepare for returning to China. "I was thinking, since I have mastered the technology of chip integrated nano-manufacturing, why should I stay in the United States and teach it to foreign students? I should go back to China and teach this knowledge to domestic students." After several trips around , In 2020, Ye Mao officially joined Beihang University.
The spring is cold, market demand, policy support, scientific research innovation... In the "spring" when "China Chip" is facing a desperate counterattack, Ye Mao is gathering momentum and working towards more possibilities. Run with all your might.
Even though he has entered his thirties, Ye Mao still maintains the original purity: fearless, moving forward indomitably; following his heart and being content with whatever comes his way.
In 2007, Ye Mao was admitted to the School of Materials Science and Engineering of Huazhong University of Science and Technology. During his college years, Ye Mao was not a particularly diligent and "obedient" student. Most of his motivation in learning came from his interest and he would do whatever he liked. One day, he suddenly came up with the idea of ??"wanting to go abroad and have a look", so he prepared for the overseas exams (TOEFL and GRE), and got a scholarship to study for a master's degree in mechanical engineering at the University of Michigan in the United States.
Ye Mao’s master’s tutor is an Indian who has a decisive influence and status at the University of Michigan in the United States. When Ye Mao came to his apprenticeship, he got a research job, which allowed him to have free tuition and a salary as a scientific research assistant, which was a very good treatment. Ye Mao asked his tutor: "My grades are not the best, and my resume is not the most beautiful. Why are you giving me such good treatment?"
Ye Mao's tutor replied, because he felt that Ye Mao was here He has his own ideas in research. Before going to the United States, Ye Mao had already had some exchanges with his mentor. During the exchange, he gave a variety of solutions to some research problems, which left a deep impression on his mentor. “He thinks this is a big highlight for me.” Following his master’s tutor, Ye Mao engaged in work related to bionic bone scaffolds using nano-biomaterials and achieved a series of results.
In 2014, Ye Mao originally planned to work directly after graduating with a master's degree. He said frankly: "My PhD study was actually a very accidental thing." At that time, Ye Mao had just found a job and accidentally met Professor Yasha Yi who had just come to work at the University of Michigan at an academic report. Through communication, the two of them became A lot of new ideas came up, and then his doctoral supervisor said to him: "Maybe we can implement them (these ideas)." In this way, Ye Mao gave up the job opportunity he got and chose to continue studying for a PhD in electrical and computer engineering at the University of Michigan.
Ye Mao’s main research direction is chip-integrated optoelectronic devices and chip-integrated nano-manufacturing technology. Simply put, the latter serves the former. In order to manufacture chip-integrated optoelectronic devices, it is often necessary to spend a lot of time and energy on chip-integrated nano-manufacturing technology.
Since 2014, Ye Mao has entered the Lurie Nano Fabrication Technology Laboratory (Lurie Nano Fabrication Facility), the top large-scale chip integration laboratory in the United States (state of the art), to learn nano-manufacturing and chip integration technology based on silicon-based materials, and has worked in This technology was gradually mastered in subsequent research work.
During his studies abroad, Ye Mao focused on optical metasurfaces and metalenses in the visible light band, light-grabbing nanostructures of medical scintillator, and chip-integrated laser radar optical phased array (OPA) devices. We have conducted in-depth and systematic research in other aspects and achieved a number of internationally leading important results.
Ye Mao developed a metalens design and manufacturing process system based on high refractive index silicon-rich silicon nitride, breaking through the design technology of metalenses that can resist etching delays and dispersion-free metalenses. , which solved the difficulties, high costs and dispersion problems in manufacturing optical metasurfaces and metalenses in the visible light band, and developed grating structure metalenses, linear polarization metalenses and metalenses with focusing structures based on the visible light band. and other integrated photonic devices; he developed light-grabbing nanostructures that can be used in medical scintillator materials, greatly improving the luminous efficiency of conventional medical scintillator; for the core polarizing component in chip-integrated lidar, he proposed an optical-based The non-mechanical controllable polarization solution combining phase matrix (OPA) and optical metasurface can greatly reduce the size, weight and cost of lidar. Relevant results have been published in more than 20 papers in well-known academic journals in the field, and one international patent has been authorized.
Among them, the optical method of designing focusing structures developed by Ye Mao was specially reported by the world-renowned technology review "MIT Technology Review", and pointed out the future application of this technology in the chip lithography industry. It has important application prospects (the title of the article is "Why metalens are about to revolutionize chip-making").
After studying and researching abroad for many years, the relationship between Ye Mao and his mentor is more like that of friends and partners, and this relationship has been maintained to this day. Ye Mao said that he and his doctoral supervisor are both very idealistic people, always thinking that they can make something to change the world. Therefore, their research is very pragmatic, and they often consider the feasibility of large-scale application of some cutting-edge technologies in the industry. For example, when developing relatively cutting-edge metalens, they need to study how to reduce costs to achieve mass production.
In constant exchanges with his tutors and other teachers, Ye Mao became more and more convinced of this value cognition: making good results is not for publishing papers, not for merit and fame, but for improving people. life and make this world a better place. "We have been moving towards this goal. When we make results, the first thing we often think about is, can this be applied? Compared with the same industry, what are its advantages? The ultimate purpose of our research must be It is to let scientific research results benefit mankind and the world," Ye Mao said.
Like a spiritual practice, Ye Mao continued to acquire knowledge, increase his knowledge, improve his abilities in the United States, and quickly grew into a well-known young scholar in the chip manufacturing industry. He said: "The development of chip integrated nano-manufacturing processes is very labor-intensive, but when you personally manufacture 40-nanometer and 20-nanometer structures and devices, you understand every detail of the chip manufacturing process, which is very valuable. experience. Now, looking back, this is one of my biggest gains in the United States."
Even though he has established his own world abroad, Ye Mao's path to return to China is still not the same. Smoothly.
After staying in the United States for more than 7 years, Ye Mao didn’t know anyone in the domestic academic community. He could only search for jobs and resumes overseas. Fortunately, many domestic schools at that time had overseas youth forums, and some universities enthusiastically extended invitations to Ye Mao.
So, during the short Christmas vacation in 2018, he returned to China and visited four universities at once. But it was not a successful journey. Compared to some of the nano-manufacturing technology and device achievements that Ye Mao presented, the teachers he met at the time seemed to be more interested in the impact factor of the paper on his resume. In the winter of that year, he learned for the first time that there was such a thing as paper partitioning.
Someone once advised Ye Mao to publish a few more papers in some high-impact journals, and then use this as a step to return to China for employment. After thinking about it, Ye Mao refused. "I may be able to do this, but this is not my original intention for doing research. The value of research results lies in whether it can promote the progress of its field. I think research that can truly solve problems and can be truly applied is good research. ." Even though his brief return in 2018 yielded nothing, Ye Mao still insisted on the idea of ??returning to China. After graduating from the Ph.D., he continued to do postdoctoral research for one year, completing the work that had not been completed before, and returned to China at the end of 2019.
This time, Ye Mao met the "Bole" who understood him - Academician Fang Jiancheng. After some in-depth exchanges, Academician Fang Jiancheng said to him: "You have done a good job in research. We really need talents like you in chip integrated optoelectronic devices and nano-manufacturing technology. We value ability more than papers." The results of practical application can solve problems, be truly useful and easy to use.” In this way, Ye Mao joined Beihang University as an associate researcher.
"To do research, you need to find like-minded people. Academician Fang and I have the same idea, which is to make something practical and useful. Rather than publishing articles, we care more about whether we can contribute to the chip integration business Let’s start by manufacturing China’s own chips in our own field and industrializing them, changing the pattern of the chip industry and making China’s chip industry catch up with or even surpass the United States,” said Ye Mao.
Compared with chip design, chip manufacturing is the key "short board" restricting the development of my country's chip integration industry. How to make optoelectronic devices into chips, make them so small while still reducing costs, with complete functions, good performance, and high yield rate is a big problem, and Ye Mao came back to solve this problem.
Utilizing years of research accumulation in the field of chip-integrated optoelectronic devices and facing the country’s development needs for key measurement and navigation instruments, Ye Mao immediately developed theoretical methods and manufacturing technologies for chip-integrated quantum precision measurement devices after returning to China. Research work mainly includes chip-integrated atomic magnetometers, chip-integrated atomic gyroscopes, functional optical metasurface technology, commercial-oriented planar integrated optical metalenses, etc., and is committed to realizing core key optoelectronic chips for our country in a short time. Technological breakthroughs provide strong technical support. At the same time, Ye Mao also carried out relevant platform construction and teaching work relying on the development of major national scientific research projects.
Having been engaged in scientific research for many years, Ye Mao rarely has negative emotions. Looking back on his journey, he said: "If there is a problem, solve it. I actually don't have that much time and energy to solve emotional problems."
When he was in the United States, although Ye Mao's team had the resources Quite a few, but there are only a few people in the team. There are only two doctors, him and his junior brother. In those years, the two of them completed one scientific research after another. Various problems may arise during the manufacturing process of chip-integrated optoelectronic devices. However, Ye Mao and his junior brothers did not complain. They just immersed themselves in their work and finally completed a number of scientific research tasks with strict engineering indicators. "Actually, we don't feel very tired. On the one hand, we do research in a planned way, and on the other hand, we use divergent thinking to think of more ways and try more. We don't have time to think: This is so difficult, what should we do if we can't do it? Or, , This is too difficult, I don’t want to do it. It’s impossible. Since we started doing it, we must do it and do it well.”
When I returned to China, although I didn’t get recognition at the beginning, Ye Mao never thought of giving up. What he still thinks is: All problems can be solved. As long as I make the results and use them, someone will recognize them one day.
It is this kind of optimism and tenacity that has made Ye Mao what he is today.
The atomic magnetometer based on the atomic spin-free exchange relaxation (SERF) effect is currently the most accurate magnetic field measurement sensor. Its theoretical accuracy can reach sub-feat level. It is currently the most accurate sensor for strategic magnetic measurement and Core device in medical biomagnetic measurement equipment. The chip-based atomic magnetometer will greatly reduce the size of the current device (from the traditional centimeter level to the millimeter or even micron level), reduce power consumption and cost, and is a must for future high-precision, miniaturized, array-based quantum magnetic sensing devices. Through the road. A variety of military and medical equipment, such as micro-quantum navigation systems, micro-deep-sea exploration systems, high-resolution brain magnetic imaging devices and in-vivo interventional biomagnetic measurement equipment, have put forward urgent needs for chip-based atomic magnetometers.
In 2014, Sandia National Laboratories in the United States, with support from the National Institutes of Health (NIH) and the Nuclear Safety Administration of the U.S. Department of Energy (DOE-NNSA), launched the microchip-based SERF Development of the principle prototype of the atomic magnetometer array (OPM). In addition, the U.S. National Institute of Standards and Technology (NIST) received funding from the U.S. Strategic Environmental and Development Research Program (SERDP). In recent years, it has developed a principle prototype of a vertically bonded atomic magnetometer suitable for chip integrated manufacturing methods, taking the lead in starting chip integrated atomic magnetometers. Magnetometer studies. At the same time, our country has also clearly put forward the urgent need for chip-integrated quantum precision measurement devices in the "14th Five-Year Plan". The core of chip-based atomic magnetometers is to solve the problem of photonics manipulation and coupling in chip-integrated atomic magnetometers. This is a multi-disciplinary interdisciplinary project of micro-nano photonics, chip-integrated nano-manufacturing and quantum precision measurement. Neck problems.
In order to solve this technical problem, Ye Mao applied for the Natural Science Foundation Youth Science Fund Project "Research on Integrated Photonics Control and Coupling Issues in Chip-based Atomic Magnetometers." In the project research, he will explore precise optical control methods and optical/quantum coupling mechanisms in chip-scale micro-atomic magnetometers, and on this basis, develop integrated photonics control and coupling for chip-based atomic magnetometers. The plan is finally combined with a micro-atom ensemble to conduct an integrated optical/quantum coupling extremely weak magnetic measurement experiment, in order to lay the foundation for the realization of a breakthrough in chip-integrated atomic magnetometers from scratch.
Solving the photonics control and coupling problems in chip-integrated atomic magnetometers is the first step to break through the existing bottlenecks and develop a high-precision, array-type, integrated precision quantum measurement system, and it is also the first step to achieve The national "14th Five-Year Plan" outline proposes urgently needed high-resolution magnetic brain imaging, deep sea/deep geomagnetic detection, and core issues to be solved by chip-based quantum measurement systems.
In terms of applications that are closer to people's lives, Ye Mao also mentioned: "For example, our mobile phones have gyroscope sensors. Although they are sufficient for people's lives, they are not yet available. To an ideal state. If the quantum gyroscope is integrated into a chip, the navigation and positioning of mobile phones will be more sensitive and accurate. Currently, most autonomous driving systems rely on lidar as the core ranging sensor, but current radars are still relatively large. , can only be placed on the roof of the car. If it is chip-based, it can not only reduce the size, but more importantly, reduce the cost. In this way, a car can be equipped with multiple chip-integrated lidars that scan in different dimensions, making autonomous driving more convenient. Accurate and safe. ”
At present, the relevant work is being carried out in an orderly manner. Ye Mao said that the meal must be eaten one bite at a time and the road must be walked step by step. Manufacturing China's own chips will not be achieved overnight, but he is willing to work tirelessly towards this goal.
In addition, Yemao is committed to building a chip-integrated clean room laboratory system using the Lowry Nanoprocessing Technology Laboratory, the top chip integrated clean room laboratory in the United States, as a template. The chip integration clean room laboratory is an important experimental manufacturing platform in the direction of microstructure and microsystems. It can play an important supporting role in the future of electronics, electrical, machinery, materials, biology, optics and other disciplines.
However, the construction of the platform is a long-term project, and the initial goal is to build a class 100 clean room, a gas purification internal circulation system, and a personnel management and use system. The expected goal in five years is to be able to manufacture nanostructures in the laboratory that exceed the precision of my country's current industrial chips.
"After returning to China, I found that domestic chip development has been booming. Many chip manufacturing laboratories have sprung up like mushrooms after a rain. However, in contrast, there is a lack of professional equipment debugging and maintenance in China. and process development and other related talents. "Although the construction of the laboratory has been put on the agenda, in the preliminary research, Ye Mao proposed to temporarily use a domestically constructed public nano-manufacturing platform. He said: "Because the country has spent a lot of money on building chip manufacturing laboratories, we must make full use of them. Compared with some mature laboratories in Europe and the United States, they may not have enough process accumulation, but the equipment is still very good. We can cooperate and use overseas process experience to carry out research and improve accuracy to maximize benefits."
At the same time, Ye Mao also said that for the sake of independent control of technology, it must be done. Establish your own laboratory, but before that, you must first cultivate or introduce a group of relevant talents. Only by establishing a mature talent reserve and management system can you better assist the construction of the experimental platform.
At Beihang University, Ye Mao plans to offer an all-English course on chip integrated nanomanufacturing. This course is currently relatively rare in domestic schools. Even in the United States, it is only offered by a few universities with excellent conditions. However, the trend in the entire industry for electronic and optical devices is towards miniaturization and miniaturization. Therefore, chip integrated nano-manufacturing technology is not only used to manufacture chips, but also is a must for manufacturing new nanostructures/devices with multiple functions. road. This technology is bound to become more and more popular in the future. Relying on his experience in teaching this course in the United States, Ye Mao hopes that by offering this course, domestic students will have a better understanding of this technology and cultivate more talents in chip integrated nano-manufacturing for our country.
Ye Mao has his own requirements and expectations for his students. First, he hopes students have a strong heart and cannot avoid or even give up because of the difficulty of research work. They must have an indomitable spirit; second, he hopes students can make the research process happier and enjoy the process of scientific research. . "Experience is the most valuable asset. Even if you don't do it in the end, you have accumulated a lot of valuable experience in the process. If you don't try and explore, how can you gain experience? I still say the same thing, When there is a problem, solve it, don’t run away, don’t give up, and have the spirit to do it.”
Play basketball, learn guitar, and practice good cooking skills by following short videos...after work. Ye Mao also lives seriously. Whether it is work or life, he maintains his own pace and is neither arrogant nor impetuous. Ye Mao does not make too many assumptions about the future, nor is he anxious about the unknown. For him, the only clear thing to do is to seize the moment, work hard, and devote himself wholeheartedly to the scientific research career he loves.