Development Trends of Electronic Chemicals in China     

By Zheng Jinhong, Beijing Kehua Microelectronic Materials Co., Ltd.
Hou Hongsen, Tsinghua University International Technology Transfer Center

The annual growth of the electronic chemicals business in China exceeded 20% during the Tenth Five-year Plan period (2001-2005). The market volume of electronic chemicals in China is expected to exceed RMB20 billion in 2010.
"Electronic chemicals" refers to fine chemical products used in the electronic industry. Major products include photoresist, high-purity reagents, special gases, encapsulating materials and silicon chip grinding/polishing materials for integrated circuits; base plate resins, anticorrosive dry films and cleaning agents for printed circuit boards; and liquid crystals, polaroids and fluorescent powders for flat panel displays.
    The average annual net growth of electronic chemicals worldwide was around 9% from 1999 to 2005. The global market volume of electronic chemicals is expected to be over US$35.0 billion in 2007. The average annual growth of electronic chemicals in China was more than 20% from 2001 to 2005. The value of China's electronic chemical output in 2007 is expected be over RMB20.0 billion, making it one of the fastest growing and most vigorous sectors in China's chemical industry. The Chinese government pays great attention to research, development and production of electronic chemicals, but with the industry still lags considerably behind advanced countries, technologically. Most varieties produced in China are medium- and low-grade products, falling far short of the demand, especially the demand for medium and high-grade electronic chemicals. Shortage is still the mode of the market today.

1. Development status of electronic chemicals from 2001 to 2005

1.1 Electronic chemicals for integrated circuits

    1.1.1 Photoetching glue
Photoetching glues (photoresists) are mainly used for micro processing integrated circuits and semiconductor discrete devices. They also have extensive applications in the manufacturing of flat panel displays, LED, inverted encapsulation, magnetic heads and precision sensors. As photoetching glues have photochemical sensitivity, they can be used to conduct chemical reactions. Photoetching glue is coated onto semiconductors, conductors and insulators. The portion that is retained after exposure can protect the bottom layer. Then an etching agent is used to transfer the micro pattern from the mask plate to the substrate to be processed. Photoetching glues are therefore key chemical materials in micro processing technology. As integrated circuits developed, the photo-etching technology has evolved from G line (436 nm) to I line (365 nm) and today, to deep ultraviolet - 248 nm to 192 nm. Photoetching glue responding to exposure to selected wave lengths of light has also been developed. With the change of exposure wave lengths, the composition and structure of photoetching glue are also making constant changes.
   Depending on the exposure source, phenolic resin - diazo anthraquinone positive photoetching glues are classified into G line positive varieties and I line positive varieties. I line photoetching glues still have the most extensive applications and are in highest demand.

Table 1  Major Photoetching Glues Used in the Manufacture
of Integrated Circuits

Photoresist group
    Film-forming resin    Photosensitizer

Cyclized rubber - double trinitride negative varieties
    cyclized rubber        trinitride compounds
Phenolic resin - diazo anthraquinone positive varieties
    phenolic resin      diazo anthraquinone compounds
248 nm varieties
    poly(p-hydroxyphenylethylene)
     photo-acid generating agents and derivatives
193 nm varieties
    polyester cyclic acrylate and copolymers    photo-acid generating agents
Electron beam varieties
    polybasic copolymers    photo-acid generating agents
Source: CNCIC


   Research in photoetching glues in China started in the 1970s. The domestic technical level was not much different from the international level in the initial stage. There is now a considerable gap of around three generations today however. China owns technologies for researching 193 nm photoetching glues and the lab test of electron beam photoetching glues for the 0.13-0.10 micron process. No large-scale production has been built up, and there are no commercialized products.
   Major units engaged in the research, development and production of photoetching glue in China include Beijing Research Institute of Chemical Reagents, Suzhou Ruihong Electronic Chemicals Co., Ltd. and Wuxi Research and Design Institute of Chemical Industry. BN-series ultraviolet negative photoetching glues that satisfy the requirements of the >2 micron process can be produced at around 20 t/a at the Beijing Research Institute of Chemical Reagents (now called Beijing Kehua Microelectronic Materials Co., Ltd.). The company has also reached the international level of the early 1990s for various application features and technical levels of these particular glues. A capacity of 5 t/a has been built up and the needs of the >0.5 micron process can be satisfied. Suzhou Ruihong Electronic Materials Co., Ltd. has developed the capacity to make around 20 t/a ultraviolet negative photoetching glues, and their actual output of these glues is around 20 tons a year. Wuxi Research Institute of Chemical Industry can make small amounts of electron beam photoetching glue.

    1.1.2 High-purity reagents
High-purity reagents are also called wet chemicals or process chemicals. They are key materials in the manufacture of semiconductors. They are mainly used in cleaning and etching chips. The consumption proportion of high-purity reagents in the semiconductor sector is roughly 4% - 8% for ammonium hydroxide, 3% - 6% for hydrochloric acid, 27% - 33% for sulfuric acid, 10% - 20% for other acids, 8% - 22% for hydrogen peroxide, 12% - 20% for etching agents and 10% - 15% for organic solvents.
   As processing dimensions of integrated circuits have become submicron and deep submicron, more stringent requirements have been set for high-purity reagents. The content of particles and impurities needs to be reduced significantly.
    Globally, leading companies engaged in the research, development and production of high-purity reagents include E-Merck of Germany, Ashland, Arch and Mallinckradt Baker of the United States, Wako and Sumitomo of Japan, Taiwan Merck, Chang Chun Petrochemical of Taiwan province. In terms of technology, the United States, Germany, Korea and Taiwan province produce large quantities of high-purity reagents for the 0.2 - 0.6 micron process. The production scale of major varieties such as hydrogen peroxide, sulfuric acid and isopropanol is 5 000 - 10 000 t/a. High-purity reagents for the 0.09 - 0.2 micron process have completed process research and started large-scale production. For high-purity reagents for the <90 nm process China has completed technical research and built up considerable production capacity.
    Major organizations engaged in the research, development and production of high-purity reagents in China include Beijing Research Institute of Chemical Reagents, Suzhou Ruihong Electronic Chemicals Co., Ltd., Jiangyin Jianghua Microelectronic Materials Co., Ltd. and also Shanghai Huayi