In August 2025, an employee secret theft case was exposed at TSMC's 15A factory. A Singaporean man surnamed Lei, who was once the deputy manager of the advanced process integration department of the factory, was sentenced for stealing confidential information before leaving his job.
Since September 2013, Lei Nan has been responsible for the integration of customers' high-performance products in the 28nm process. Before resigning in August 2016, he used his off-duty time to copy 50 pages of the company’s “Security C” confidential information three times, including 6 pages of protective layer test data, 42 pages of indicator data, and 2 pages of process data. Less than a month after leaving his job, he joined SMIC North, a subsidiary of SMIC that competes with TSMC, as director of the production technology engineering center.
During the court hearing, Lei Nan admitted to copying materials, but denied premeditating the transfer of technology to China. He argued that copying materials was to prepare for an internal promotion at TSMC, and that the new position did not involve process research and development. The judge determined that the material he copied was a high-value trade secret that affected TSMC's competitiveness, and was sentenced to one year in prison for "the crime of reproducing trade secrets beyond the scope of authorization."
Because Lei Nan had no criminal record and was willing to reflect, the court sentenced him to three years of probation and ordered him to pay 500,000 yuan to the public treasury. Regarding the charge of "intending to use secrets in the mainland" charged by the prosecutor, because the two parties did not have a non-compete agreement and the prosecutor did not prove his involvement in SMIC's process technology, he was ultimately acquitted due to insufficient evidence.