The country of origin of Silicon Wafers

N345524 February 12, 2025 OT:RR:NC:N2:209 CATEGORY: Origin George Tuttle, III Tuttle Law Offices 3950 Civic Center Drive, Suite 310San Rafael, CA 94903 RE:  The country of origin of Silicon Wafers Dear Mr. Tuttle, III: In your letter dated January 30, 2025, you requested a country of origin ruling on Silicon Wafers on behalf of your client Wafer Works Epitaxial Corporation. The items concerned are silicon wafers manufactured within Taiwan, which have an epitaxial growth layer added within China.   At the time of manufacture within Taiwan, the wafers are almost 100% silicon and are doped for use in electronics. The wafers are doped with either boron, phosphorus, or arsenic based on the customer’s request and design. Boron is used for P-type doping to provide an excess of positive charge carriers called “holes.” Phosphorus and arsenic are used for N-type doping to provide an excess of negative charge carriers. The silicon epitaxial layer is also doped, with the same chemical element that is used to dope the wafer. Boron doped silicon wafers from Taiwan undergo boron doped epitaxy in China (homoepitaxy). Similarly, phosphorus doped silicon wafers from Taiwan undergo phosphorus doped epitaxy in China, and arsenic doped silicon wafers from Taiwan undergo arsenic doped epitaxy in China. As the epitaxial layer is doped with the same chemical element as the base wafer, (i.e. boron doped wafer with epitaxial layer of boron doped silicon) there is no change in the electrical attributes of the wafer. Once the epitaxial layer is added, the wafer does not incorporate a positive/negative (p/n) junction. The positive/negative(p/n) junction is formed during downstream customer fabrication. The manufacturing steps performed within Taiwan: Ingot Formation: Crystal Growth End Cropping Ingot Inspection Section Cropping OD Grinding Wafer Manufacturing: Slicing the Silicon Ingot Measurement and Inspection Crude Edge Grinding Lapping of the Wafer Fine Edge Grinding Edge Profile and Geometry Measurement Double Side Grinding Measurement and Inspection Hard Laser Marking Caustic Etching and Cleaning Heat Treatment Double-Sided Polishing Edge Polish Chemical-Mechanical Polishing (CMP) Geometry and Flatness Measurements Appearance Inspection Final Cleaning Surface Scan Sorting RFID Writing Packaging and Shipment to China for epitaxial growth process The process that is to occur in China involves adding a silicon epitaxial layer to the wafer substrate. Autoepitaxy (or Homoepitaxy) is the extension of the substrate lattice by the overgrowth of a layer of identical material (e.g., Si in Si, or GaAs in GaAs) with no problem of compatibility or mismatch. The manufacturing steps performed within China: Epitaxy Process: Epitaxy refers to the growth of a single crystal layer on the substrate wafer. This is achieved by application of thin-film deposition. Visual Inspection Measurements for Thickness, Resistivity, and Flatness Final Cleaning Particle Measurement Packaging/ Shipping When determining the country of origin for purposes of applying current trade remedies under Section 301, the substantial transformation analysis is applicable. See, e.g., Headquarters Ruling Letter (“HQ”) H301619, dated November 6, 2018. The test for determining whether a substantial transformation will occur is whether an article emerges from a process with a new name, character, or use different from that possessed by the article prior to processing. See Texas Instruments Inc. v. United States, 681 F.2d 778 (C.C.P.A. 1982). This determination is based on the totality of the evidence. See National Hand Tool Corp. v. United States, 16 C.I.T. 308 (1992), aff’d, 989 F.2d 1201 (Fed. Cir. 1993). Based upon the facts presented, it is the opinion of this office that the processing that takes place within Taiwan is both meaningful and complex, resulting in the creation of doped silicon wafers (blank wafers). The character of these particular wafers is imparted by the material used to manufacture the wafer (silicon) and the type of dopant used to provide a particular electrical attribute (positive or negative).  The wafer would be considered the dominant component. The wafers do not undergo a substantial transformation as a result of the manufacturing process that takes place within China. The wafers retain their identity and predetermined end use. Their electrical attributes are not changed as a result of the Chinese processing, (i.e. no P/N junction is formed). Therefore, since a substantial transformation does not occur as a result of the Chinese manufacturing steps, the country of origin of the epitaxial (blank) wafers will be Taiwan for the purposes of applying current trade remedies under Section 301. The holding set forth above applies only to the specific factual situation and merchandise description as identified in the ruling request. This position is clearly set forth in Title 19, Code of Federal Regulations (CFR), Section 177.9(b)(1). This section states that a ruling letter is issued on the assumption that all of the information furnished in the ruling letter, whether directly, by reference, or by implication, is accurate and complete in every material respect. In the event that the facts are modified in any way, or if the goods do not conform to these facts at time of importation, you should bring this to the attention of U.S. Customs and Border Protection (CBP) and submit a request for a new ruling in accordance with 19 CFR 177.2. Additionally, we note that the material facts described in the foregoing ruling may be subject to periodic verification by CBP. This ruling is being issued under the provisions of Part 177 of the Customs and Border Protection Regulations (19 C.F.R. 177). A copy of the ruling or the control number indicated above should be provided with the entry documents filed at the time this merchandise is imported. If you have any questions regarding the ruling, please contact National Import Specialist Steven Pollichino at steven.pollichino@cbp.dhs.gov. Sincerely, Steven A. Mack Director National Commodity Specialist Division