MAR-2-85:OT:RR:NC:N2:209
George Tuttle, III
Tuttle Law Offices
3950 Civic Center Drive, Suite 310
San Rafael, CA 94901
RE: The country of origin of a silicon wafer
Dear Mr. Tuttle:
In your letter dated September 29, 2022, you requested a country of origin ruling on behalf of your client, Silicon Materials Inc.
The items concerned are silicon wafers of various sizes, ranging in diameter from 2” to 8”; incorporating dopants B, P, Sb and As; having both 100 and 111 orientations; an oxygen content of 10-20 ppm; a carbon content 0.5-1.0 ppmA; and having various resistivity ranges, mechanical properties and surface qualities.
The semiconductor wafers, which are to be sliced and polished in Belarus, are produced from
monocrystalline silicon ingots, or boules, which are “pulled” or produced in the Ukraine from U.S. originating electronic-grade polysilicon.
The U.S. originating electronic-grade polysilicon is substantially transformed into monocrystalline silicon ingots in the Ukraine, with physical and electrical properties that are
distinct and different from the U.S. originating polysilicon, making it useful for integrated circuit
production.
Silicon Materials Inc. (SMI) purchases the U.S. origin electronic-grade polysilicon and exports it to the Ukraine, to produce monocrystalline silicon ingots.
The most common method to grow a single crystal ingot is the Czochralski method
which is used to produce the crystalline silicon wafers in question.
The ingot production process that takes place in the Ukraine consists of the following:
Preparing the electronic-grade polysilicon for ingot formation – The removal of surface impurities using chemical treatments. The electronic-grade polysilicon is placed in cascading acid baths of nitric acid (HNO3) and hydrofluoric acid (HF), which act to etch and remove the outside surface of the EGS to a depth of about 300 - 400um. The acids are removed by rinsing the EGS in deionized water. The electronic-grade polysilicon crystals are dried in air-free furnaces and packed into polyethylene bags to await further processing.
Preparation of High Purity Polysilicon - The electronic-grade polysilicon crystals are placed into a quartz crucible for heating. The crucible is heated until the polysilicon crystals are molten (at 1425° C) in the presence of an inert gas, such as argon, which prevents the reintroduction of contaminants. The creation of a wafer with a positive or negative current imparts the essential character of a semiconductor wafer. These positive or negative currents are made by doping, which is the intentional introduction of contaminants. P-doping creates a positive current. The opposite occurs in N-doping, which creates a negative current.
Growing or “Pulling” the Ingot - To provide the lattice structure desired for a monocrystalline semiconductor, a seed crystal is created in the laboratory at Prolog, Ukraine. A seed crystal is a small piece of single crystal material from which a larger desired crystal of identical structure is to be grown. The specifically designed seed crystal (undoped, B, P or other doping agent) is precisely oriented on a rod and dipped into the saturated molten solution. The seed crystal that is attached to the rod is dipped to just below the surface of the molten silicon. The rod is then drawn or “pulled” upwards very slowly, at a rate of 30 - 40mm per hour and simultaneously rotated as the crucible rotates in the opposite direction. By controlling the temperature gradient, rate of pulling, and speed of rotations, it is possible to extract a large, single crystal. The molten semiconductor material will slowly solidify into a crystal based on the lattice structure of the seed, resulting in a rod of single or monocrystalline semiconductor material. The ingot, or “boule”, can vary in size from 2 inches (50.8mm) to 8 inches (200mm) in diameter and up to a meter long.
Testing the Semiconductor Ingot - Prior to export from Ukraine to Belarus, test wafers/disks are cut using a water cooled saw from the semiconductor ingot. The disks are then tested to determine and evaluate their physical and electrical properties. Each wafer is then measured for specific electromechanical parameters. In order to eliminate the resistivity influence of thermal donors, the ingots are annealed in a special furnace, ranging from 100°C to 740°C.
Mechanical Treatment of Ingots - After all the necessary measurements and annealing is completed, the silicon ingot is subjected to mechanical processing to give it the required geometric parameters, such as diameter, length, and primary and secondary flat.
Packing the Ingots for Transport - After mechanical treatment, the ingots are packed into carton or wooden boxes for shipment to Belarus for further processing.
SMI processes the semiconductor ingots into wafers in Belarus. This process is consistent
with wafer preparation procedures regardless of where preformed, and consists of the following:
Grinding & Cropping - The outer circumference of the ingot is ground to a uniform diameter and the boule is cropped to a specific length.
Slicing & Beveling - Once shaped, the ingot is sliced using a diamond-etched saw to create wafers of ~1mm thickness, based on the required conductivity or resistivity. The outside edge of the wafer is beveled to an arc to enhance edge strength and to reduce chipping.
Measuring Initial Sample Thickness - This step is to ensure that each wafer has the required uniform dimensional thickness prior to lapping and polishing.
Bonding Wafers to a Substrate Prior to Lapping and Etching - After being measured, the wafer is bonded to a carrier disk or glass substrate. This allows the wafer to be handled throughout the lapping and polishing stages. The bonded substrate is mounted onto a jig for lapping and etching.
Lapping & Etching - The lapping process is undertaken so that the surface of the wafer is completely smooth and as flat as possible. Lapping is a mechanical process in which a pad with polishing liquid (a mixture of nitric, hydrochloric, and acetic acids) is used to remove excess silicon from a wafer substrate, thus creating a smooth even surface. Chemical etching removes any debris created during this process.
Final Inspection & Packaging of Wafers - A visual inspection of the wafer surface for defects is performed. The process ends when the wafers are packaged into moisture-proof shipping cases while still in the clean room, for eventual export.
A complete manufacturing process description and explanation has been provided.
The marking statute, Section 304, Tariff Act of 1930, as amended (19 U.S.C. 1304), provides that, unless excepted, every article of foreign origin (or its container) imported into the U.S. shall be marked in a conspicuous place as legibly, indelibly, and permanently as the nature of the article (or its container) will permit, in such a manner as to indicate to the ultimate purchaser in the U.S. the English name of the country of origin of the article.
The “country of origin” is defined in 19 CFR 134.1(b) as “the country of manufacture, production, or growth of any article of foreign origin entering the United States. Further work or material added to an article in another country must effect a substantial transformation in order to render such other country the 'country of origin' within the meaning of this part.”
For tariff purposes, the courts have held that a substantial transformation occurs when an article emerges from a process with a new name, character or use different from that possessed by the article prior to processing. United States v. Gibson-Thomsen Co., Inc., 27 CCPA 267, C.A.D. 98 (1940); National Hand Tool Corp. v. United States, 16 CIT 308 (1992), aff’d, 989 F. 2d 1201 (Fed. Cir. 1993); Anheuser Busch Brewing Association v. The United States, 207 U.S. 556 (1908) and Uniroyal Inc. v. United States, 542 F. Supp. 1026 (1982).
However, if the manufacturing or combining process is merely a minor one that leaves the identity of the article intact, a substantial transformation has not occurred. Uniroyal, Inc. v. United States, 3 CIT 220, 542 F. Supp. 1026, 1029 (1982), aff’d, 702 F.2d 1022 (Fed. Cir. 1983). Substantial transformation determinations are based on the totality of the evidence. See Headquarters Ruling (HQ) W968434, date January 17, 2007, citing Ferrostaal Metals Corp. v. United States, 11 CIT 470, 478, 664 F. Supp. 535, 541 (1987).
Based upon the facts presented, it is the opinion of this office that the manufacturing processes that take place within the Ukraine impart the essence to the product. The monocrystalline silicon ingots, or boules, (which incorporate the desired electrical qualities as a result of the doping and manufacturing processes) manufactured within the Ukraine do not undergo a substantial transformation as a result of the manufacturing process that takes place in Belarus. The slicing, grinding and polishing processes do not effect a substantial transformation of the product. The products retain their identity as semi-conductor medium with a predetermined end use. Therefore, since a substantial transformation does not occur as a result of the Belarus manufacturing process, the country of origin for marking purposes would be the Ukraine upon importation into the United States. The monocrystalline silicon wafers should be legibly, conspicuously, and permanently marked in accordance with the requirements of 19 U.S.C. 1304 to indicate that its country of origin is the Ukraine.
This ruling is being issued under the provisions of Part 177 of the Customs 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, contact National Import Specialist Steven Pollichino at [email protected].
Sincerely,
Steven A. Mack
Director
National Commodity Specialist Division