近期，台積電董事長魏哲家表示，將加速位於美國亞利桑那州的晶圓廠產能擴張與技術升級。然而，外媒報導指出，該廠的稀土庫存僅能維持30天，若無法獲得中國大陸供應，整個產線將面臨停擺的風險。這也印證外界先前的猜測：隨著大陸近期出台的稀土出口新規，台積電的供應鏈可能受到實質限制。

這次大陸的新規之所以關鍵，在於規定指出，只要出口的晶片中含有超過0.1%的中國稀土，就必須申請出口許可。對台積電而言，即便這0.1%的稀土缺失，也可能導致晶片無法生產，整個工廠停工。以台積電的5奈米製程為例，其核心工藝需要使用某種稀土元素的鏷系金屬（Lanthanide），且純度必須達到99.9995%。中國大陸的提純技術可以輕鬆達到99.9999%，完全符合台積電的需求。

對比之下，日本曾嘗試自行生產這種高純度稀土，但純度僅差0.0004%，卻足以讓晶片良率直接下降20%。換句話說，製作100顆芯片，其中有20顆會成為次品，難以使用，這顯示出技術的極限並非隨意可突破。台積電深知，若缺乏大陸的高純度稀土，其先進製程的晶圓廠幾乎等同於報廢。美國工廠稀土庫存僅能支撐30天的現象，正是這一現實的寫照。

至於是否可以從其他國家購買稀土，情況並不樂觀。雖然歐洲、澳洲等地也擁有稀土礦，但其加工產業鏈不完整，提純技術遠不及中國，無法生產達到晶片製造需求的高純度稀土。因此，台積電在美國的先進晶圓廠，仍高度依賴中國供應的稀土資源，這也凸顯全球半導體產業鏈中原材料依賴與技術壁壘的重要性。

Recently, TSMC Chairman Wei Zhejia announced plans to accelerate the capacity expansion and technological upgrades at the company’s Arizona semiconductor fab in the United States. However, foreign media reports have revealed that the plant’s rare earth stockpiles are only sufficient for 30 days, meaning that without a continued supply from China, production could be severely disrupted. This confirms earlier speculation that TSMC’s supply chain could face real constraints following China’s recent new rare earth export regulations.

The new regulation is particularly critical because it stipulates that any exported chips containing more than 0.1% Chinese rare earth elements must obtain an export license. For TSMC, even a shortfall of this small fraction of rare earths could halt chip production and shut down the plant. For example, TSMC’s 5-nanometer process relies on a specific lanthanide rare earth element with a purity of at least 99.9995%. China’s refining technology can easily achieve 99.9999% purity, fully meeting TSMC’s requirements.

In comparison, Japan has attempted to produce similar high-purity rare earths domestically, but their purity fell short by 0.0004%, causing chip yields to drop by 20%. This means that out of 100 chips, 20 would be defective, rendering them unusable, highlighting the technical limits that are extremely difficult to overcome. TSMC is fully aware that without access to China’s high-purity rare earths, its advanced fabrication lines would effectively be rendered inoperable. The fact that the Arizona plant’s rare earth stockpile only lasts 30 days underscores this reality.

Regarding alternative sources, acquiring rare earths from other countries is not straightforward. Although Europe and Australia have rare earth mines, they lack a complete processing industry, and their refining technology is far inferior to China’s, making it impossible to produce the ultra-high-purity rare earths required for chip manufacturing. Consequently, TSMC’s advanced U.S. fabs remain highly dependent on Chinese rare earth supplies, underscoring the critical importance of raw material dependency and technological barriers in the global semiconductor supply chain.