By Wen-Yee Lee

TAIPEI (Reuters) -Taiwanese silicon wafer manufacturer GlobalWafers (6488.TWO) said on Friday it would invest an additional $4 billion in the United States to meet growing customer demand there, as it officially opened its new $3.5 billion wafer facility in Texas.

"Our U.S. customers appear to have a very strong demand for U.S.-based production capacity,” Doris Hsu, Chairperson of GlobalWafers, a TSMC (TSM) supplier, told reporters.

"Although tariffs (on semiconductors) have not been finalized…(U.S.) customers are hoping to secure local supply to reduce the potential uncertainties that tariffs may bring."

The plant, GlobalWafers' most advanced fully integrated 300mm (12 inch) silicon wafer facility, is the first of its kind built in the U.S. in more than two decades and is currently the only advanced wafer manufacturing site in the country.

Silicon wafers are critical components in chip manufacturing and larger wafers are widely used in advanced chip production as they allow for more chips to be produced per each wafer, increasing cost savings.

At the opening ceremony held in Sherman, Texas, on Thursday, the company said it intends to add two more phases to the site to boost production capacity. It currently has one phase completed for production and a second phase is planned for construction in the 142-acre campus that is designed to accommodate up to six phases.

Hsu said there is no set timeline for the additional two phases, but several conditions must be met before moving forward.

“Phases one and two must be profitable, and we need to secure customers... who show strong interest in local production and are willing to sign long-term contracts,” Hsu said.

“We also need reasonable pricing, prepayments, and government support. If these conditions are met, we’ll move ahead.”

The plant is part of the Biden administration-era CHIPS for America program and the company is set to receive $406 million in U.S. government grants for its projects in Texas and Missouri.

Hsu said it has not yet received the U.S. funding but has reached key milestones and submitted the required documentation. Hsu expected the funds to be disbursed in the first half of this year.

Reuters reported in February the Trump administration is seeking to renegotiate U.S. CHIPS and Science Act awards and has signalled delays to some upcoming semiconductor disbursements.

U.S. President Donald Trump has repeatedly criticized the CHIPS Act and said in March U.S. lawmakers should get rid of it and instead use the proceeds to pay debt.