In the current complex international environment, independent innovation in science and technology has become a strategic choice for China to safeguard its national security and development interests. In various fields of scientific and technological innovation, semiconductor chips are undoubtedly the top priority. Recently, Chinese researchers have made a major breakthrough in the field of optical chip manufacturing technology and successfully developed a new method of mass production of low-cost and high-performance optical chips, which will undoubtedly further enhance the independent innovation strength of the mainland chip industry and help the independent and controllable development of the semiconductor industry.
Strong demand has led to technological innovation
The so-called optical chip refers to a new type of chip that uses optical signals instead of traditional electrical signals to transmit and process data information. Compared with traditional electronic chips, optical chips have unique advantages in signal transmission rate and anti-interference ability, and are regarded as the "next generation of chips" after electronic chips.
Due to the above advantages, optical chips have broad application prospects in many fields such as communication, computing, and remote sensing, and the market demand is strong. Taking the field of communication as an example, in the era of 5G and the future 6G, emerging applications such as video communication and ultra-high-definition image transmission have put forward higher requirements for network bandwidth, and optical fiber networks and optical interconnection technologies will become popular, thus giving rise to a huge demand for optical chips.
In the field of computing, with the development of emerging technologies such as artificial intelligence and big data, traditional electronic chips are also facing severe challenges in terms of computing speed and energy efficiency. In addition, high-performance optical chips also play an indispensable role in optical systems such as lidar and precision measurement.
However, it is regrettable that due to the constraints of relevant basic theories and manufacturing processes, optical chips have long been regarded as a "neck" technology, which restricts the overall development process of the mainland chip industry. In the face of urgent needs, Chinese researchers have overcome difficulties and innovated independently in the field of optical chips, and finally made this major technological breakthrough.
Lithium tantalate opens up a new path for photonic chips
The key to this new breakthrough in optical chip manufacturing technology is the use of a new photonic material called lithium tantalate (LiTaO3). Lithium tantalate is an inorganic nonlinear optical crystal material with excellent optical properties, thermal stability and electro-optical properties, and is widely used in optoelectronic devices, precision measuring instruments and other fields.
Theoretically, lithium tantalate can be a high-quality material for the manufacture of optical chips. However, the traditional process has very harsh requirements for the growth conditions of lithium tantalate crystals, resulting in the inability to achieve low-cost mass production. If lithium tantalate material is applied to optical chip manufacturing, it will completely solve the problem of high production costs.
After years of hard work, the Chinese scientific research team has finally broken through this bottleneck and developed a new lithium tantalate flat wafer technology. Different from the traditional crystal growth technology, this technology adopts a principle and process similar to silicon wafer drawing, which can manufacture lithium tantalate optical waveguide flat wafers in batches and at low cost, thus providing a solid material foundation for the production of optical chips.
At the same time, researchers have also innovatively combined lithium tantalate with silicon-based photonic integration technology to develop a new lithium tantalate-silicon photonic integrated chip. The chip not only has the excellent optical properties of lithium tantalate, but also can effectively connect with the existing silicon-based chip processes and devices, reducing the threshold of technology migration and industrialization, and realizing a high degree of integration of optoelectronic integration.
Industry experts said that this new optical chip technology route based on lithium tantalate can fundamentally solve the material and process obstacles of current large-scale production. It is foreseeable that in the future, integrated optical path chips based on lithium tantalate will play a role in the fields of ultra-high-speed optical interconnection networks, precision measurement, and photonic computing.
Improve the independent and controllable industrial chain
The breakthrough in optical chip manufacturing technology will greatly enhance the mainland's independent innovation capability in the field of photonic integrated circuits and chips, and add an important link to the construction of a complete independent and controllable semiconductor industry chain.
In fact, in recent years, China has shown a firm determination to be self-reliant and self-reliant in core technologies such as integrated circuits and semiconductors. In the chip manufacturing process, SMIC, YMTC and other domestic manufacturers continue to make breakthroughs in their advanced process capabilities; In terms of chip design, local companies such as Instrinsic and UNISOC have also made great progress; Although there are still shortcomings in the field of key materials and equipment in the upstream of the industrial chain, they have begun to move towards independent and controllable.
The major breakthrough in optical chip technology will enable the mainland to be more comprehensive and systematic in terms of independent and controllable high-end chips. Traditionally, photonic integrated circuits have been regarded as a new track in chip technology. Overcoming the "stuck neck" problem of mass production of optical chips has cleared the obstacles for the industrialization and large-scale application of this new track, and formed a good complement to the previous progress in the fields of memory chips and radio frequency chips.
For the entire chip industry chain, this breakthrough will undoubtedly have a chain effect. The large-scale production of upstream lithium tantalate flake materials will lead to the development of new lithium tantalate preparation equipment and processes; The midstream optoelectronic integrated manufacturing process needs to be integrated with the existing silicon-based production line, which puts forward new requirements for the original process and equipment; In terms of downstream terminal products, a large number of emerging application scenarios will also be derived.
It is worth noting that at the same time, China has also increased investment and deployment in other links such as photonic integrated circuit design tools, software, chip packaging and testing. Therefore, a photonic integrated circuit industry chain covering the whole process from materials, equipment, manufacturing to design, packaging and testing is taking shape. Compared with a single link, the interlocking complete industrial chain can better ensure product quality and supply, and avoid the risk of "stuck neck".
Further, the formation of the optical chip industry chain will also have a spillover effect on other semiconductor industry chains. First, the technological achievements of advanced manufacturing processes and equipment can be reused in other chip fields; Second, photonic integrated circuits complement current electronic chip products, helping to build more advanced and high-performance heterogeneous systems; Third, optoelectronic coupling products will give rise to new application scenarios and needs, and promote the in-depth development of the entire semiconductor industry.
Therefore, we can foresee that in the process of construction and improvement of the optical chip industry chain, the overall strength of China's semiconductor industry will continue to increase, the level of autonomy and controllability will continue to improve, and it is steadily moving towards the strategic goal of building a complete local ecosystem.
The potential for industrial application is promising
At present, the research and development of engineering products has become the key work of China's scientific and technological personnel, and optical chips are also entering a critical stage of transformation from principle breakthroughs to application product development. The core components of various photonic integrated circuits based on lithium tantalate materials are being developed and tested simultaneously, such as narrow linewidth waveguides, high-speed photodetectors, new silicon optocouplers, etc.
At the same time, the research and development of integrated chips for a series of cutting-edge application scenarios such as ultra-high-speed optical interconnection integrated chips for next-generation data centers and cloud computing, silicon-based light guide designs for advanced lidar, and radiation-resistant optical circuits for automotive-grade applications have also been in full swing.
These system-on-chip products will be widely used in 5G/6G communications, precision guidance, artificial intelligence chips and other fields in the future, and have huge market prospects. Taking 5G/6G communication scenarios as an example, optical fiber broadband access technology is becoming more and more mainstream, and the introduction of optical chips can not only provide extremely high transmission bandwidth, but also greatly reduce system power consumption. This will pave the way for gigabit and even 10 gigabit wireless broadband applications.
In the field of precision guidance, the low loss and ultra-wideband characteristics of lithium tantalate optical chips can be applied to new lidar systems to provide high-precision target detection and ranging capabilities for autonomous vehicles and airborne guidance. In terms of AI chips, the parallel computing advantages of photonic integrated circuits can help break the upper limit of computing power of traditional chips and release the potential of computing power. These will become the main application areas of optical chips in the future.