China Imposes 99% Anti-Dumping Deposit on Japanese Chip Chem

China’s Commerce Ministry unveiled preliminary anti-dumping measures on imports of dichlorosilane from Japan on September 7, requiring companies to provide cash deposits of up to 99.2% starting September 8. The action targets a chemical crucial for semiconductor production, adding another layer to the escalating diplomatic dispute between Beijing and Tokyo over Taiwan. The deposit rates affect all Japanese producers of the chemical used to process silicon wafers into chips, with Shin-Etsu Chemical Co facing the highest rate of 99.2%, while Denal Silane Co faces 80.8%.

The measures represent a fairly targeted move that nonetheless escalates tensions between the two Asian economic powers. Chief Cabinet Secretary Minoru Kihara stated that Tokyo will closely examine the measures, assess their impact and work with firms to prevent undue disruptions on businesses. The action comes ahead of Prime Minister Sanae Takaichi‘s expected visit to the United States in September and before Chinese leader Xi Jinping meets US President Donald Trump at the White House on September 24.

Dichlorosilane, abbreviated as DCS, carries the chemical formula SiH₂Cl₂ and functions as a silicon-containing gas used in chip manufacturing. Its main function supplies the silicon feedstock needed to form films on wafer surfaces, including epitaxial silicon, silicon nitride, silicon oxide, polysilicon, and other films under specific reaction conditions. These films form part of chip structures or insulating layers, meaning DCS may be used in logic, memory, and analog chips across the semiconductor industry.

Understanding the Chemical’s Strategic Importance

DCS operates as an electronic specialty gas and a consumable used in semiconductor manufacturing, where the challenge extends beyond merely synthesizing a compound. Suppliers must control impurities consistently, maintain batch-to-batch stability, and manage contamination risks associated with cylinders, filling, transportation, and gas delivery. Shin-Etsu‘s own product materials identify high-purity refining, strict quality control, and container delivery management as competitive strengths that differentiate Japanese suppliers in the global market.

Japanese suppliers’ advantages stem largely from their long record of stable supply and established customer relationships. A wafer fab must verify that changing materials will not affect film quality or production yield, creating substantial barriers even when domestic alternatives cost less. This explains why a relatively small materials market can still have high barriers to entry that protect incumbent suppliers from rapid displacement by new competitors.

Japan holds the position as the global leader in ultra-high purity dichlorosilane, though China has sought to expand upstream in the chip supply chain by nurturing research and development of key materials and tools. The technical demands of producing ultra-pure chemicals for semiconductor applications create natural advantages for established producers who have refined their processes over decades of continuous operation.

Origins and Trajectory of the Trade Investigation

China’s action first reflects a clear request from a domestic producer, as Tangshan Sunfar Electronic Materials Co., Ltd. filed an application on December 8, 2025, prompting the Ministry of Commerce to open the investigation on January 7, 2026. At initiation, the Ministry cited preliminary evidence showing that imports from Japan increased overall from 2022 to 2024, while prices fell by about 31% cumulatively and the domestic industry suffered injury.

Two details in the preliminary determination prove important for understanding the competitive landscape: Japanese products were still priced higher than domestic products in China, and their market share was declining. The Ministry’s ruling indicates that China’s concerns center not on absolute price levels but on the rate of price decline and its impact on domestic producers attempting to establish themselves in this specialized market.

Japan used to be China’s biggest supplier of dichlorosilane, until South Korea overtook it in 2025. In July 2026, imports from Japan were worth US$2.6 million, accounting for about 33% of China’s total dichlorosilane imports, according to customs data. For now, importers must pay security deposits to Chinese Customs, with the final duty rates to be determined in the final ruling following the completion of the investigation.

Diplomatic Context and Taiwan Tensions

Beijing and Tokyo have been embroiled in a feud since November 2025, when Prime Minister Sanae Takaichi suggested Tokyo could deploy its military if China attempts to seize Taiwan, a self-ruled democracy claimed by Beijing. Since then, China has responded with moves like warning travellers to avoid Japan and tightening some export controls on strategic materials and technologies.

The timing of the dichlorosilane measures adds economic pressure to an already tense diplomatic environment. The preliminary ruling represents part of a broader pattern where trade measures become instruments in geopolitical disputes, affecting supply chains that cross multiple borders and involve numerous stakeholders. The semiconductor industry, already facing disruptions from pandemic-era shortages and geopolitical realignments, now confronts another source of uncertainty in materials procurement.

Market Impact and Supply Chain Implications

The 99.2% deposit requirement effectively prices Japanese dichlorosilane out of competitiveness in the Chinese market, forcing importers and semiconductor manufacturers to seek alternative sources. Price alone proves insufficient to justify an immediate switch when changing materials requires extensive verification to ensure film quality and production yield remain unaffected. This creates a dilemma for Chinese chipmakers who must balance cost considerations against technical risk and production continuity.

China’s Commerce Ministry stated that dumping caused substantial harm to China’s domestic industry, providing the legal basis for the anti-dumping action under international trade rules. The deposit rates distinguish between specific Japanese producers, with Denal Silane Co receiving a somewhat lower rate of 80.8% compared to the 99.2% applied to Shin-Etsu Chemical and all other Japanese companies.

The measures accelerate a shift already underway in supply patterns, as South Korea’s rise to become China’s largest dichlorosilane supplier in 2025 demonstrates. Japanese producers face not only the immediate cash deposit burden but also the likelihood that Chinese customers will establish new relationships with alternative suppliers, making it difficult to regain market share even if the final ruling proves less restrictive than the preliminary measures.