Sourcing doped SiC wafers from China

Duty on doped silicon carbide wafers

Heading 3818 covers chemical elements doped for electronics in discs, wafers or similar forms, and chemical compounds doped for electronics. Doped silicon carbide is a compound rather than elemental silicon. The relevant line in the supplied tariff facts is 3818 00 90 00, described as other.

Read from the UK Trade Tariff on 19 October 2026, the relevant line carried 0% duty for goods from China. The supplied facts list no anti-dumping or countervailing duty, suspension or attached import control for this line. Only this line is relevant to the focused table.

Give your broker the composition, doping details, intended electronic use and processing state to confirm the commodity code. See the silicon wafers guide for the wider heading and UK import duty and VAT for the calculation method.

Specify the crystal and electrical properties

Specify crystal structure, dopant identity, conductivity type, resistivity range and measurement method. Agree diameter, thickness, thickness variation, bow, warp, crystal orientation, offcut and identification notch or flat. State whether you want bare substrates or wafers with an epitaxial layer, and which face must be polished.

Set acceptance criteria for micropipes, dislocations, scratches, edge chips and surface contamination. Request wafer identification and lot-linked electrical, dimensional and defect maps. If an epitaxial layer is ordered, specify its thickness, doping and uniformity separately from the substrate.

UK REACH generally applies to individual chemical substances on their own, in mixtures or in articles. Before importing or selling in Great Britain, assess the supplied wafer's status and your obligations using its composition, form and intended use. Treat this assessment separately from the tariff classification.

Worked duty example

Illustrative example, not a quote: Illustrative order of 200 doped silicon carbide wafers under 3818 00 90 00, invoiced at £30,000 free on board, with £2,500 of freight and insurance to the UK. The customs value is £32,500. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £32,500, so it is £6,500. With no duty, the only import tax is the VAT, which a VAT-registered importer can usually reclaim. The import duty and VAT guide explains each step.

Inspection checklist

Identity: match wafer and carrier identifiers to the order, crystal structure, dopant and lot reports.

Geometry: compare measured thickness, variation, bow, warp and orientation with the agreed specification and measurement method.

Electrical and defects: compare resistivity and defect maps with the agreed limits; check that reports identify the supplied lot.

Surface and packing: inspect for cracks, chips, scratches and contamination; check secure individual separation and record transit damage before unpacking the lot.

What goes wrong

A wafer can match the ordered diameter while having the wrong crystal orientation, resistivity or surface finish. Lot averages can conceal local electrical variation or concentrated defects. Agree whether acceptance uses wafer maps, individual results or lot sampling before production.

Edge damage and contamination can arise during handling and transit. Generic reports make it difficult to connect a defect to a supplied wafer. Keep identifiers and packaging photographs, and hold disputed material apart while the supplier investigates.

Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification. For repeat volumes, see container programmes.