A keen insight into the frontier of microelectronics
In the last century, information science and technology developed vigorously, and microelectronics, as the technical basis of the information age, became a hot topic. At that time, Hao Yue, who was emerging in the field of microelectronics, keenly felt that the traditional research on microelectronics technology had encountered problems.
The basic research of integrated circuit technology with silicon as semiconductor material has become the core of people's attention. On the one hand, with the integration of integrated circuits doubling every 18 months, the basic research of semiconductor devices and materials is highly dependent on process conditions, and the advantages of universities are slowly losing; On the other hand, with the industrialization of related technologies and the rapid development of the industry market, the development and application of integrated circuit technology has rapidly become the world of enterprises, and it is difficult for universities and even scientific research institutes to become the leading force.
Finding a new direction is the inherent requirement of academic leader Hao Yue. He turned his attention to compound semiconductors, and finally focused on the wide band gap semiconductor materials-gallium nitride and silicon carbide, which just started in the world. He saw that the study of wide band gap semiconductor materials can closely combine electronics and optics, and it must have advantages that simple electronics or optics do not have. At the same time, it also has high academic and application value and is easy to form the first-Mover advantage.
Around 2000, Hao Yue went to the United States for academic exchange. He paid close attention to the latest research trends in the United States and found that their research on nitride wide band gap semiconductor materials was still in its infancy. This strengthened his determination. After returning home, he resolutely announced that he would turn to a new research direction, wide band gap semiconductor materials and devices.
According to Ma, a young teacher in the laboratory, it was like a blockbuster, which caused quite a shock in the college and many people could not understand it. At that time, as a teacher's doctoral student, Ma was also surprised by the unexpected. Broadband gap semiconductor is a new thing, and no one can predict its development prospect. There is no research foundation and no financial support. In Ma's view, this new unknown area is full of risks.
Despite the controversy, Hao Yue is very determined. Without financing, without conditions, we will create conditions and make every effort. Colleagues and students all lamented that Mr. Hao was courageous and decisive, and what he saw and heard never dragged his feet.
Only a few years have proved that the mountain that Hao Yue led his team to climb is a treasure. Gallium nitride and silicon carbide compound semiconductor materials, that is, wide band gap semiconductor materials, were quickly defined as "third generation" semiconductor electronic materials, which opened a new page in the world microelectronics discipline and microelectronics industry.
Build an innovation platform independently
At the beginning of studying wide band gap semiconductor material gallium nitride, the biggest problem that Hao Yue faced was the lack of material growth equipment. It took 7 million to 8 million to introduce a set of equipment. However, due to the lack of research foundation, it is impossible to apply for state funding support.
What shall we do? Hao Yue decided to make a set of equipment by himself. He squeezed out some funds from the project funds in his hand, paid by himself, and finally got enough 2 million, thus starting the arduous course of independent research and development and building a material development platform.
With this 2 million yuan to buy parts, team members design and manufacture their own equipment. The hardest part is actually in the beginning Hao Yue encouraged everyone to say that the most painful time is also the most hopeful time. When the days are good, we will have a sense of crisis.
In 2002, under the leadership and guidance of Hao Yue, the first generation of MOCVD equipment was successfully developed. Zhang Jincheng, a young teacher who directly participated in equipment research and development after graduation, recalled the past of "starting with welding boards with students" and felt more fulfilled. This set of equipment, which was later called "workshop" by Zhang Jincheng, met the most basic research needs of material growth, characterization and testing, and soon grew GaN-based epitaxial materials with international advanced level. The success of the team has taken a crucial first step.
At the same time, worldwide, the era of wide band gap semiconductors is coming. Academics and industry have gradually realized that GaN electronic devices are ideal materials for manufacturing high-power microwave and millimeter-wave devices, and have great application prospects in the new generation of aerospace platform equipment such as wireless communication, radar, navigation measurement and control. However, the defect density of GaN materials is relatively high, which has long been a bottleneck restricting the development of GaN electronic devices.
Hao Yue led the team to systematically study and reveal the physical mechanism of defects in the growth of GaN electronic materials, and creatively put forward the pulse time-sharing transport method and the crown growth method of alternating three-dimensional island growth and two-dimensional plane growth, which significantly suppressed the defects.
Based on the curing integration of this innovative growth method, the team successfully established the first-generation self-made MOCVD system and low-defect material growth process, and quickly updated them to the second and third generations in 2005 and 2007, which solved the international problem of high-performance GaN electronic material growth and promoted the application of GaN material growth technology and core equipment. The MOCVD system and key technologies independently developed by the team have been successfully industrialized and applied to the manufacturing enterprises of GaN semiconductor microwave devices and photoelectric devices, with an accumulated output value of 2 1 10,000 yuan. Since 2003, their self-made high-performance GaN electronic materials have been applied to many domestic research institutes and universities in batches, as well as some research institutions in Japan, Singapore and other countries, and have been evaluated by international users as "the characteristics have reached the international frontier level". It seems that in the morning and evening, Professor Hao Yue and his team produced a batch of demonstrative achievements, which shook the whole microelectronics field.
The transformation of achievements highlights value.
In 2002, GaN high brightness blue LED devices were successfully produced in Hao Yue Laboratory. This new process has incomparable advantages in energy saving compared with traditional light emitting devices. Hao Yue foresees the huge market potential of this achievement, and vigorously promotes technology transfer and achievement transformation.
However, things didn't go well at first. Obviously, the value of this new thing has not been recognized by the market and has not attracted enough attention. Hao Yue believes that no matter how good an achievement is, it can't be regarded as the final success if it doesn't realize its due value. Hao Yue decided to rely mainly on the team's own strength to transform this mature technology as soon as possible.
In 2005, the team transferred this achievement with a small amount of technical shares, and established Xi Anzhongwei Optoelectronic Technology Co., Ltd. with the technical support of the laboratory, which successfully realized the industrialization of blue-green and ultraviolet LEDs.
In addition, the domestic GaN microwave and millimeter wave power devices independently established by them filled the domestic blank, broke the technical blockade and embargo of developed countries, and were tried in several national key projects of radar and measurement and control, which promoted the leap-forward development and application of broadband semiconductor electronic devices in China.
Provide high-quality GaN and SiC epitaxial wafers to enterprises and scientific research institutes in batches. Microwave power devices have been used in national key projects; Gan's LED achievements have become the core technology of semiconductor lighting in Shaanxi Province. The reliability technology of micro-nano devices has played an important role in promoting the development of high-reliability integrated circuits in China ... With the application of many achievements in national and national defense key projects, the research work led by Hao Yue has been widely concerned at home and abroad, and the scientific research level and academic status have been continuously improved.
In solving the major strategic needs of the country, the team noticed that the reliability of semiconductor devices has always been a prominent weak link in aerospace, aviation and other systems. The Ariane rocket in the United States has experienced 8 failures during the multiple launches of 100, 7 of which were caused by individual equipment failures. With the increasing complexity of electronic systems, the reliability of devices is becoming more and more prominent, especially in China.
Hao Yue has been paying attention to this technical problem for many years. Since the end of last century, under his leadership, the team has systematically studied the degradation and failure mechanisms of various semiconductor devices, proposed and established corresponding models, and systematically revealed the physical essence of semiconductor device degradation and failure. This achievement won the third prize of National Science and Technology Progress Award from 65438 to 0998.
As early as 200 1, the team first proposed and established a high-reliability self-aligned trench gate semiconductor device structure and manufacturing process, which improved the reliability of the device by nearly two orders of magnitude, and was evaluated as "trench gate device is a promising structure, which can improve the hot carrier effect and thus improve the reliability of the device". This achievement has been successfully applied to the mass production of high reliability integrated circuits by SMIC, a famous integrated circuit manufacturer. This achievement also won the second prize of National Science and Technology Progress Award in 2008.
"Microelectronics are not small" is a phrase that Hao Yue often talks about. Microelectronics technology is the embodiment of a country's core competitiveness and the symbol of its comprehensive national strength. He said that as researchers, we should undertake our own mission.
Facing the future, Hao Yue, on the one hand, pays attention to the frontier hotspots of the discipline, on the other hand, reflects on some problems in the team's sustainable development: the mathematical foundation needs to be further consolidated and strengthened, the innovative thinking needs to be further cultivated, and the scientific spirit, passion and vitality need to be further stimulated ... He always seems to have a sense of urgency that waits for no time.
On a beautiful lawn in xidian university South Campus, a huge stone stands tall, and the four characters of "Four Seas and One Heart" are heroic and vigorous, as if telling the persistence and struggle, dreams and pursuits of Xidian Microelectronics.