We are substantially dependent on sales of our products and services to customers outside the United States. International sales, including export sales from our U.S. manufacturing facilities to non-U.S. customers and sales by our non-U.S. subsidiaries, accounted for 84.1% of total revenue in 2023. Customers based in Asia dominate our international sales. Ion implanter system shipments to customers in Asia represented 74.2% of total system revenue in 2023. We anticipate that international sales will continue to account for a significant portion of our revenue. In particular, we expect that sales to Chinese customers (both global and domestic Chinese chip manufacturers) will continue to represent a significant portion of our total sales, creating both risk and opportunity.
U.S. export controls on shipments to Chinese customers have been notably increasing since 2020. Since the placement of SMIC on the U.S. Entity List in 2020, we are required to obtain export control licenses to ship to mature process SMIC fabs, which to date, we have been able to obtain. Other chipmakers have been placed on the Entity List, without a similar policy allowing licensed shipments. A new export controls regulatory framework issued by the U.S. in October 2022 and supplemented in October 2023, prohibits all semiconductor equipment shipments to Chinese customers (other than certain multi-nationals) who are producing or developing logic, DRAM and NAND chips meeting specific advanced parameters. While these regulations have further excluded exports to certain Chinese customers, we currently are able to continue to ship to the majority of our Chinese customers. In general, however, continuing revenue from Chinese customers is at higher risk than continuing revenue form customers in some other international locations because of trade tensions between the United States government and the Chinese government, and other challenges reflecting China's stage of development and rapid growth.
Increased U.S. export controls and other political and trade tensions exacerbate the risk that Chinese customers will change suppliers to non-U.S. vendors, such as Advanced Ion Beam Technology, Inc., Nissin Ion Equipment Co., Ltd. and Sumitomo Heavy Industries Ion Technology Co., Ltd. In addition, a Chinese entity, known as CETC Electronics Equipment Group Co., Ltd., is developing ion implanters for the Chinese domestic market. The loss of a significant customer or any reduction or delays in our ability to ship to any significant customer will adversely affect us.
We source a substantial portion of our materials from outside of the United States. Because of our dependence upon international sales and our global supply chain, our results and prospects may be adversely affected by a number of factors, including:
- changes in laws or regulations resulting in more burdensome governmental controls, tariffs, restrictions, embargoes or export license requirements;- volatility in currency exchange rates;- political and economic instability;- global health emergencies, such as pandemics, which have the potential to disrupt our manufacturing operations and those of our supply chain, as well as cause our customers to delay or cancel shipments;- difficulties in accounts receivable collections;- extended payment terms beyond those customarily offered in the United States;- difficulties in managing suppliers, service providers or representatives outside of the United States;- difficulties in staffing and managing foreign subsidiary operations; and - potential adverse tax consequences.