Taiwan Semiconductor Manufacturing reported that the US last year approved 99 percent of its patent applications, which placed the tech giant among the top patent holders in the US.

In its Corporate Social Responsibility Report, TSMC said it last year secured about 3,600 patents worldwide, including more than 2,300 in the US.

As of the end of last year, TSMC owned more than 39,000 patents, the report said.

The company last year filed almost 6,500 patent applications worldwide and ranked among the top 10 patent applicants in the US. In Taiwan, it was the largest patent applicant for the fourth consecutive year.

As of the end of last year, TSMC had filed more than 55,000 patent applications worldwide.

The chipmaker, which has a more than 50 percent share of the world’s pure wafer foundry business, said that to protect its intellectual property, maintain a lead over its peers and boost its competitive edge, it is determined to strengthen its intellectual property portfolio.

Also in the report, TSMC said it last year spent US$2.96 billion on research and development (R&D), a new high in the company’s history.

Last year’s R&D spending rose 4 percent from a year earlier, with its R&D workforce growing 5 percent to 6,534.

The expenses amounted to about 8.5 percent of TSMC’s total sales last year.

The company has said it expects its R&D spending would equal 8.5 percent of its annual revenue until 2030.

TSMC reported record-high sales last year of NT$1.07 trillion, and forecast that sales this year would grow 14 to 19 percent, so its R&D spending is expected to reach another high, ranging between US$3.37 billion and US$3.52 billion.

Analysts said that TSMC’s R&D spending is the reason the chipmaker over the past few years has been able to serve as the sole processor provider to Apple Inc for iPhone production.

Through its R&D efforts, TSMC has also secured large orders from HiSilicon Technologies Co — an integrated circuit design unit of Chinese telecom equipment supplier Huawei Technologies Co — and US clients such as Advanced Micro Devices Inc, Nvidia Corp and Qualcomm Inc, as well as Taiwanese IC designer MediaTek Inc, analysts said.

Analysts also said that TSMC not only leads South Korean rival Samsung Electronics Co, but has also left its Chinese competitor Semiconductor Manufacturing International Corp about two generations behind.