Semiconductor equipment series - photolithography machine is the "crown" in the semiconductor industry.
1. Principle
Photolithography refers to the chemical change of photoresist under the action of special wavelength light or electron beam. Through subsequent exposure, development, etching and other processes, A fine processing technology that transfers graphics designed on the mask to the substrate. The laser is used as a light source to emit a beam. After the optical path is adjusted, the beam penetrates the mask and the lens. The optical error is compensated by the objective lens, and the pattern is exposed on the silicon wafer with photoresist, and then developed on the silicon wafer.
2. Development history
The development of lithography machines has gone through five generations of product iterations. Before 1985, the light source of the first-generation lithography machine was mainly the 436nm g-line mercury lamp source, which was only suitable for processes above 5 μm. Later, the second-generation lithography machine with the 365nm i-line mercury lamp source appeared. The process accuracy has reached 350-500nm. The third generation is a scanning projection lithography machine. The light source is improved to a 248nm KrF krypton fluoride excimer deep ultraviolet light source, achieving leapfrog development and advancing the minimum process to 150-250nm.
The fourth generation is a step-type projection lithography machine, which uses a 193nm wavelength ArF argon fluoride excimer laser light source to advance the process to 65-130nm. The fifth generation is the EUV lithography machine, which has chosen a new solution to further provide shorter wavelength light sources.
3. Market
Currently, the global lithography machine market is monopolized by ASML of the Netherlands and Canon and Nikon of Japan. Therefore, statistics of the three companies can represent the entire industry. Currently, China also has its own lithography machines, but the technical level is far behind that of foreign leaders. Shanghai Microelectronics Equipment Co., Ltd. (SMEE) has achieved mass production of 90nm node lithography machines through active research and development. Using ArF light source, it can meet the needs of 90nm and above processes. Domestic lithography machines are seeking breakthroughs at the next technology node.
4. Industrial chain
The lithography machine industry chain mainly includes three major links: upstream core components and supporting equipment, midstream lithography machine production, and downstream lithography machine application. Lithography machine technology is extremely complex and has the highest technical content among all semiconductor manufacturing equipment.
5. Localization of lithography machines
After Huawei was restricted by US chips, the localization of lithography machines became a hot topic. However, the localization of lithography machines is not a task that can be completed overnight. The lithography machine is a very complex system and a collection of multiple precision technologies. Almost every segment requires the cooperation of top industry suppliers to complete it. It is impossible to complete the research and development of photolithography machines by just one or two companies working behind closed doors.
A number of outstanding domestic companies have emerged in the core components and supporting facilities of lithography machines, including dual workbench manufacturer Huazhuo Precision Technology, light source system manufacturer Fujing Technology, photoresist manufacturer Nanda Optoelectronics and Large photosensitivity, etc. Although there is a "long road ahead" and many parts and raw materials of photolithography machines are stuck; however, "the road is coming". By continuously cultivating talents and improving the industrial chain, I believe that one day we can achieve a breakthrough!