The tariff classification of a dynamic gas lock membrane device from the Netherlands

N361571May 29, 2026CLA-2:OT:RR:NC:N1:104
CATEGORY: Classification
TARIFF NO.: 8486.90.0000
Edward Juliano, Jr.Edward F. Juliano, Jr. - Attorney at Law303 Wyman Street, Suite 300Waltham, MA 02451RE: The tariff classification of a dynamic gas lock membrane device from the NetherlandsDear Mr. Juliano:In your letter dated
May 15, 2026
, you requested a tariff classification ruling on behalf of your client, ASMLUS, LLC.The product in question is a dynamic gas lock membrane device (DGLM), designed solely for use withinASML’s extreme ultraviolet (EUV) semiconductor lithography system. The DGLM is installed within thewafer stage region as a specialized membrane assembly positioned directly above the semiconductor waferduring lithographic processing. EUV light reflects off the lithography machine’s reticle, then six mirrors, andthen passes through the DGLM membrane before exposing the semiconductor pattern on the wafer.You state that the primary function of the DGLM is to act as a physical barrier to prevent carbon particlesand contaminants from degrading the semiconductor wafers and optical components within the EUV system.The secondary function of the DGLM is to block certain (non-EUV) wavelengths of light from reaching thewafer. The DGLM contains channels that allow hydrogen gas to flow above the device and holds themembrane that blocks light of certain wavelengths from reaching the wafer to be exposed. The DGLMconsists mostly of aluminum with components of stainless steel, synthetic rubber, and plastics.The DGLM will be shipped as a replacement or upgrade for the EUV system’s existing contaminationprotection methods. Because the DGLM membrane becomes contaminated and damaged on a molecularlevel over time, it must be periodically removed and cleaned or replaced.You suggest that the DGLM is properly classifiable in subheading 8486.90.0000, Harmonized TariffSchedule of the United States (HTSUS), as a part of a semiconductor lithography machine. We agree. Anarticle is a “part” if it is dedicated solely for use with another article and is not a separate and distinctcommercial entity. See United States v. Pompeo, 43 C.C.P.A. 9, 14 (1955). The DGLM is solely used withthe EUV lithography system, performing a vital role in preventing contaminants from reaching and degrading
the semiconductor wafer, as well as blocking non-EUV light from damaging the wafer or otherwisenegatively affecting image performance. It is specially shaped to fit into the lithography machine and has noother function or use.The applicable subheading for the dynamic gas lock membrane device will be 8486.90.0000, HTSUS, whichprovides for “Machines and apparatus of a kind used solely or principally for the manufacture ofsemiconductor boules or wafers, semiconductor devices, electronic integrated circuits or flat panel displays;machines and apparatus specified in note 11(C) to this chapter: parts and accessories: Parts and accessories.”The general rate of duty will be free.The duties cited above are current as of this ruling’s issuance. Duty rates are provided for your convenienceand are subject to change. The text of the most recent HTSUS and the accompanying duty rates are providedat https://hts.usitc.gov/.This ruling does not address the applicability of any additional duties, taxes, fees, exactions and/or othercharges, which may apply to the goods discussed herein. This includes, but is not limited to, tariffs and otherduties as provided for in Subchapter III to Chapter 99, HTSUS. Thus, for example, in addition to theclassification stated above, the merchandise covered by this ruling may also need to be reported with eitherthe Chapter 99 provision under which an additional tariff applies or one of the Chapter 99 provisionscovering exceptions to such tariffs.For further information to assist with the importation process, please refer to the frequently updated CargoSystems Messaging Service (CSMS) messages at https://www.cbp.gov/trade/automated/cargo-systems-messaging-service and the Trade Remedies page at https://www.cbp.gov/trade/programs-administration/trade-remedies.The holding set forth above applies only to the specific factual situation and merchandise description asidentified 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 theinformation furnished in the ruling letter, whether directly, by reference, or by implication, is accurate andcomplete in every material respect. In the event that the facts are modified in any way, or if the goods do notconform to these facts at time of importation, you should bring this to the attention of U.S. Customs andBorder 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 periodicverification by CBP.This ruling is being issued under the provisions of Part 177 of the Customs and Border ProtectionRegulations (19 C.F.R. 177).A copy of the ruling or the control number indicated above should be provided with the entry documentsfiled at the time this merchandise is imported. If you have any questions regarding the ruling, please contactNational Import Specialist Arthur Purcell at [email protected].
Sincerely,
(for)James P. ForkanDirectorNational Commodity Specialist Division