The Chinese side has targeted Japan's advantageous chip material, silicon dichloride. Japanese media are quite sensitive to this and interpret it as China using economic and trade means to 'pressure' Japan. At the same time, Japan's once powerful 'card' in the Chinese market no longer holds its former prominence.
On September 8th, the Japanese government responded to China's latest measures. Japanese Minister of State Kihara Minor stated that Japan would maintain close communication with relevant Japanese companies, carefully study the situation and impacts of China's investigations, and take appropriate measures to prevent Japanese companies' business activities from being "undesiredly affected."
The previous day, the Chinese Ministry of Commerce announced preliminary rulings in the anti-dumping investigation against imports of dichlorodihydrosilane originating from Japan. It was determined that the related products were dumped, and the domestic industry in China suffered substantial damage. There was a causal relationship between dumping and the substantial damage. Starting from September 8th, import operators must provide bonds to Chinese customs at a ratio of 80.8% to 99.2% when importing related Japanese products.
Jiangsu Nantong: Workers are rushing to produce orders for semiconductor micro-nano devices. IC Photo
Dichlorosilicon is mainly used for thin-film deposition in the chip manufacturing process. It can be used to produce logic chips, storage chips, and analog chips, among others.
According to the initial Chinese evaluation, the Japanese chemical giant Shin-Etsu Chemical Industry Co., Ltd. and other Japanese companies are subject to a deposit ratio of 99.2%, while Denka Silane Co., Ltd. is subject to an 80.8% deposit ratio. All interested parties can submit written comments within 10 days from the date of the announcement.
The Japan Times quickly followed up, stating that this move is considered part of Beijing's "pressure actions" against Japan. The Japanese media specifically mentioned that shortly before China initiated an anti-dumping investigation into dichlorosilane in January this year, it had already strengthened controls on the export of dual-use items to Japan. These measures are closely linked to the remarks made by Japanese Prime Minister Masayoshi Motegi regarding Taiwan.
Bloomberg also reported on the 8th that China's adoption of anti-dumping measures is an attempt to 'increase pressure on Japan' in the diplomatic disputes surrounding the Taiwan issue, and this measure is included among a series of recent counter-measures taken by China against Japan.
In fact, similar claims appeared at the beginning of the investigation. In January this year, Japanese semiconductor industry media TECH+ stated that while China has increased export controls on certain products to Japan, it is also investigating the import of Japanese semiconductor materials into China. This shift from verbal warnings to actual actions is seen as a deliberate attempt to set an example, akin to “killing a chicken to scare off others.”
These media attempts to find motives in Sino-Japanese relations. The reasons given by the Chinese side for the investigation are as follows. The Ministry of Commerce stated that this investigation was initiated officially on January 7th of this year, at the request of domestic industries. After the case was filed, the investigation was carried out strictly in accordance with Chinese laws and regulations, as well as WTO-related rules.
The Ministry of Commerce reported in January this year that preliminary evidence shows that the quantity of dichlorosilicon imported from Japan has been on an upward trend from 2022 to 2024. The price of dichlorosilicon decreased by 31% over this period. The applicant believes that the related dumped imported products have caused damage to the production and operation of domestic industries in China.
After the investigation began, the stock price of Shinetsu Chemical fell nearly 4% during trading on January 8. Following the initial ruling measures, Shinetsu Chemical stated that it is studying related measures. According to a statement from the company's spokesperson cited by AFP, dichlorosilicon accounts for only a "very small portion" of the company's business, and it is expected to have no significant impact on the overall business.
However, Japan does have an advantage in this field. Bloomberg describes Japan as a global leader in ultra-high purity dichlorosilicon. The Japanese semiconductor industry media TECH+ also reported that Japanese-produced dichlorosilicon is highly regarded globally due to its ultra-high purity. Major suppliers include Showa Denko, Daioch Chemical, Sumitomo Chemical, and Japan Air Liquide.
A document on the semiconductor supply chain released by the European Commission this year indicates that semiconductor manufacturing is highly dependent on ultra-pure process gases and precursors, including chlorosilane-based precursors related to dichlorosilane. These materials have strict requirements regarding purity, impurity content, packaging, and supply stability. Changing the supplier often requires re-certification, and it may also lead to risks related to yield and reliability.
But in the Chinese market, another change has taken place.
Bloomberg cited Chinese customs data, stating that Japan used to be China's largest source of dichlorodimethylsilane imports, but this position was overtaken by South Korea in 2025. In July of this year, China imported about $2.6 million worth of dichlorodimethylsilane from Japan, which accounted for approximately 33% of the total imports of this product that month.
The report also noted that China has been continuously promoting the research and development of key semiconductor materials and equipment in recent years, advancing towards the upstream of the semiconductor industry chain. Japan still possesses technical and supply advantages in high-purity dichlorosilane, but with the entry of other overseas suppliers and the development of domestic Chinese companies, the environment in which Japan operates in the Chinese market is no longer the same as it was in the past.
The Japanese chemical industry has also begun to consider this change. The Chemical & Engineering News, an publication of the American Chemical Society, interviewed people from the Japanese chemical industry after launching an investigation in China. The report mentioned that Japanese companies still place great importance on the Chinese market, but they are also paying attention to the uncertainties in Sino-Japanese economic and trade relations.
In the eyes of Japanese media, the impact of this "stimulation" on Japanese companies remains to be seen. However, with Japan losing its position as China's largest source of imports, and China accelerating its efforts in self-developed semiconductor materials, this business that once had a clear advantage for Japan is beginning to change its market landscape.
The Ministry of Commerce emphasized on the 7th that China has always used trade relief measures cautiously and restraintfully, and firmly upholds fairness and free trade. In the next step, investigations will continue in accordance with the law, and the rights of all interested parties will be fully protected.
