Xi'an University of Electronic Science and Technology (XUEST) Professor Hao Yue and his scientific research team on wide bandwidth semiconductor technology, relying on the State Key Laboratory of Wide Bandwidth Semiconductor Technology (WBST), carries out applied basic research on wide bandwidth semiconductor materials and devices, and the laboratory has become an important base for domestic and international scientific research on wide bandwidth semiconductor materials and devices, training of personnel, academic exchanges, and the transformation of results. Xi'an University of Electronic Science and Technology microelectronics and solid state electronics national key disciplines, "211 project" key construction disciplines and national integrated circuit talent training base of the important support.
Sharp insight into the frontiers of microelectronics
In the last century, information science and technology flourished, and microelectronics, an integrated circuit that serves as the technological foundation of the information age, became a big hit. At that time, Hao Yue, who had already made a name for himself in the field of microelectronics, was keenly aware that traditional microelectronics research had already encountered problems.
Silicon as the semiconductor material for the basic research of integrated circuit technology has become the center of attention. On the one hand, with the integration of integrated circuits doubled every 18 months, so that the semiconductor devices and materials basic research is highly dependent on the process conditions, the advantages of the university is slowly lost; 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 business, universities and even research institutes are difficult to become the dominant force.
Looking for a new direction is an intrinsic requirement that academic leader Hao Yue intuited. He turned his attention to compound semiconductors, and ultimately focused on the international just started wide-band semiconductor materials - gallium nitride, silicon carbide. He saw that wide-band semiconductor materials research can be closely integrated with electronics and optics, and will inevitably have simple electronics or optics does not have the advantage, but also has a high academic and application value, easy to form a first-mover advantage.
Before and after 2000, Hao Yue went to the United States for academic exchanges, and he paid attention to the latest developments in related research in the United States, and found that their nitride wide-band semiconductor materials research is still in its infancy. This strengthened his determination. After returning to China, he resolutely announced that he would shift to a new research direction, broadband semiconductor materials and devices.
Ma Peijun, a young teacher in the lab, recalled that this was like a heavy bomb, which caused a lot of shock in the college, and many people could not understand. As a doctoral student of Mr. Hao Yue at that time, Ma Peijun also felt very sudden and surprised. Wide-band semiconductor is a new thing, no one can predict its development prospects. With no research foundation and no financial support, Ma Peijun thought that this new and unknown field was full of risks.
Despite the controversy, Hao Yue was very determined. There is no funding to raise funds, there are no conditions to create the conditions, to put up all their efforts. Colleagues and students have exclaimed that Mr. Hao is bold and decisive in his decision-making, and he will never drag his feet on what he sees as right.
Shortly a few years time has proved, when Hao Yue led his team to climb this mountain is a treasure. Gallium nitride, silicon carbide compound semiconductor materials, also known as wide-band semiconductor materials, soon defined as the "third generation" semiconductor electronic materials, which opened the world microelectronics disciplines and microelectronics industry a new page.
Independently build innovation platform
Starting the research on gallium nitride, a broadband semiconductor material, the biggest problem in front of Hao Yue is that there is no material growth equipment. The introduction of a set of equipment, then need 7 million to 8 million yuan. However, due to the lack of research basis, can not apply for state funding support.
What to do? Hao Yue decided not to wait and build a set of equipment by himself. He squeezed out part of the project funds from the hands of the funds, and their own advances, scraping together, and finally came up with 2 million yuan, which began the independent research and development and build a materials development platform of the hard course.
With the 2 million yuan to buy parts, team members to design and build their own equipment. Everything is difficult at the beginning, Hao encouraged everyone, the most painful time, but also the most hopeful time, when the days are better, we have to have a sense of crisis.
In 2002, under the leadership and guidance of Hao Yue, the first generation of MOCVD (chemical vapor deposition of organic compounds) equipment was successfully developed. Zhang Jincheng, a young teacher who graduated and stayed in school at that time and was directly involved in the research and development of the equipment, recalled that period of time when he "led the students to start from welding boards", and felt more of a sense of accomplishment. This set of equipment, which was later laughingly called "workshop" by Zhang Jincheng, met the most basic research needs such as material growth, characterization, testing, etc., and soon grew GaN (Gallium Nitride)-based epitaxial materials with international advanced level. The team has successfully taken the first step of critical significance.
Meanwhile, worldwide, the era of wide-band semiconductors was fast approaching. Academia and industry are gradually recognizing that GaN electronics is an ideal material for manufacturing high-power microwave millimeter-wave devices, and has significant application prospects in next-generation wireless communications, radar and navigation measurement and control, and other aerospace and aviation platform equipment. Just GaN material defect density is relatively high, which is the bottleneck of the long-term constraints on the development of GaN electronic devices.
Hao Yue led his team to systematically study and reveal the physical mechanism of defect formation in the growth of GaN electronic materials, ingeniously proposed a pulsed time-dependent transport method, three-dimensional island growth and two-dimensional planar growth alternating with the crown growth method, which significantly inhibited the defects.
It is based on the solidification and integration of this innovative growth method, the team successfully established the first generation of independent localized MOCVD system and low-defect material growth process, and rapidly updated to the second and third generation in 2005 and 2007, solving the international problems of high-performance GaN electronic material growth, and promoting 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 GaN semiconductor microwave devices and optoelectronic devices manufacturing enterprises, and have achieved a total output value of 210 million yuan. Their independent preparation of high-performance GaN electronic materials since 2003 batch applied to a number of domestic research institutes and universities, as well as Japan, Singapore and other countries, some scientific research institutions, by the international user evaluation as "the characteristics of the international frontier level". Seemingly overnight, Prof. Hao Yue and his team came up with a batch of results with a degree of display, shaking the entire field of microelectronics.
Results of the transformation of the value
In 2002, GaN high-brightness blue LED devices in Hao Yue's laboratory was successfully launched. This new process has a traditional light-emitting devices incomparable energy saving and other advantages. Hao Yue predicted that the results of the huge market potential, efforts to promote technology transfer and transformation of results.
However, things did not go very well at first, apparently the value of this new thing is not recognized by the market, did not attract enough attention. Hao Yue believes that even the best results, if "in the boudoir people do not know", did not realize its due value, can not be considered the final success. Without waiting, Hao decided to rely mainly on the team's own strength, the mature technology as soon as possible.
In 2005, the team to a small amount of technology shares to transfer the results of the laboratory for the technology, the establishment of the Xi'an Zhongwei Optoelectronics Technology Co., Ltd. successfully realized the industrialization of blue-green, ultraviolet LED.
In addition, their independent establishment of localized GaN microwave millimeter-wave power devices to fill the gaps in the country, breaking the technological blockade and embargo of the developed countries, has begun to trial in a number of radar and measurement and control of the national key projects, to promote China's broad-band semiconductor electronic devices across the development and application.
High-quality GaN (Gallium Nitride) and SiC (Silicon Carbide) material epitaxial wafer batch to provide enterprises and research institutes to use; microwave power devices have begun to be used in national key projects; GaN LED results have become the core technology of semiconductor lighting in Shaanxi Province; micro and nano device reliability technology to promote the development of China's highly reliable integrated circuits plays an important role! ...... With a number of results applied to national and national defense key projects, the research work of the team led by Hao Yue has gained wide attention at home and abroad, and the scientific research level and academic status have been continuously improved.
In addressing major national strategic needs, the team noted that semiconductor device reliability has been a prominent weak link in aerospace, aviation and other systems. There have been 8 failures in more than 100 launches of U.S. Ariane rockets, 7 of which were caused by individual device failures. With the increasing complexity of electronic systems, device reliability issues are becoming more and more prominent, more so in China.
Hao Yue has been focusing on this technical challenge for many years. From the end of last century, the team under his leadership systematically studied the degradation and failure mechanism of a variety of semiconductor devices, proposed and established the corresponding model, systematically reveals the physical nature of the degradation and failure of semiconductor devices. The result won the third prize of the National Science and Technology Progress Award in 1998.
As early as 2001, the team proposed and established for the first time a highly reliable self-aligned slot-gate semiconductor device structure and fabrication process, which improved the reliability of the device by nearly two orders of magnitude, and was evaluated as "Slot-gate device is a promising structure to improve the hot-carrier effect, thus improving the reliability of the device". This achievement has been successfully utilized in the mass production of high-reliability integrated circuits by Semiconductor Manufacturing International Corporation (SMIC), a well-known IC manufacturer. The result also won the second prize of the 2008 National Science and Technology Progress Award.
"Microelectronics is not micro," is a phrase that Hao Yue often talks about. Microelectronics technology is the embodiment of a country's core competitiveness, is a symbol of the country's comprehensive national strength. He said that as a scientific researcher, he should take up his mission.
Facing the future, Hao Yue on the one hand, pay close attention to the discipline's frontiers of the ups and downs of the hot spots, on the one hand, reflecting on the team's continued development of some of their own problems: mathematical and scientific foundations to be further consolidated and strengthened, innovative thinking needs to be further cultivated, the spirit of science, the spirit, the passion and vitality of science needs to be further stimulated ...... him! There always seems to be a sense of urgency.
A beautiful lawn on the south campus of the Xi'an University of Electronic Science and Technology, a huge stone towering, the book "four seas with the core" four big words majestic pale, seems to tell the Xidian microelectronics people's perseverance and struggle, dreams and pursuits.