TOKYO OHKA KOGYO CO., LTD. (TOK) provides chemical products, such as photoresist, and equipment for semiconductors and displays.

HOME CSR Environmental ActivitiesCreating New Environment Value through Business Activities

Environmental Activities

Corporate Social Responsibility

Promotion of recycling, managing chemical substances,
and approaches toward energy saving.

Creating New Environment Value through Business Activities

To contribute to decarbonization through business, TOK focuses on the development and stable supply of EUV/ArF photoresists to achieve further miniaturization and power consumption reductions for semiconductors, as well as KrF excimer laser photoresists for 3D-NAND, and i-Line photoresists for power semiconductors, plasma ashing systems, and wafer handling systems.
  To lead technological innovation, TOK accelerated the development of materials for next-generation Ga2O3 (gallium oxide) / SiC (silicon carbide) / GaN (gallium nitride) power semiconductors that substantially improve power efficiency, as well as materials
for 6G (next-generation communication standard), which will consume only 1/100 power of 5G systems.
  In particular, TOK will create shared value for decarbonization on a long-running basis by further developing the relationship of trust built over more than 20 to 30 years with many customers, particularly in the power semiconductors-related industry

Develop new technology that contributes to decarbonization

Develop in-house recycling ecosystem based on “chemical looping”

As a new initiative, we strive to develop an in-house recycling ecosystem based on chemical looping.

Collect super-high-concentration CO2 without using air for reaction

TOK discharges organic solvent effluents generated in the manufacturing process after partial recycling, combustion, and detoxification. Usually, the separation and recovery of CO2 through the normal combustion of effluents in the air takes considerable
energy because the CO2 in the exhaust gas is only approximately 13%* due to the large shares of atmospheric O2 and N2 that are not used for combustion. In addition, atmospheric N2 is oxidized through combustion. In general, a thermal power plant is considered to emit 30 to 100 ppm of thermal NOx after denitration treatment.
  In contrast, TOK is developing a system based on chemical looping, where atmospheric oxygen is not used in the reaction, and high-concentration CO2 can be selectively collected by controlling and optimizing reactive conditions. This system can also
minimize thermal NOx because the reaction temperature is lower than for normal combustion. Investigations using present experimental equipment have indicated a CO2 conversion efficiency of 95% or higher and a NOx level of approximately 1 to
10 ppm (lower measurement limit at present), demonstrating the superiority of this system. Currently, joint research with universities and other research institutions is in progress toward in-house practical application of this system. Subsequently, we will also pursue energy recycling and CO2 conversion linked to this system.
  The system still has many problems to clarify, we will persistently continue with long-running development as our characteristic as part of our contribution to decarbonization.
* Calculated values

Black Resist

Color filters are essential to the operation of color LCDs. The filter has four colors: red, green, blue and a black matrix. Chrome is normally used to form the black matrix. However, we have eliminated chrome, which is a source of pollution, by replacing it with a black resist.

We have positioned the black resist as one of our strategic products and continue to work on developing black resist products.

Structure of a color filter

*The black matrix is the black border of the lattice containing red, green and blue squares. This black matrix is used to produce an image with greater contrast.

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