Taiwan Semiconductor Manufacturing Company Limited (TSMC) is a semiconductor foundry. The Company is engaged in the manufacturing, selling, packaging, testing and computer-aided design of integrated circuits and other semiconductor devices and the manufacturing of masks. It operates through foundry segment. The foundry segment is engaged in manufacturing, selling, packaging, testing and computer-aided design of integrated circuits (IC) and other semiconductor devices and the manufacturing of masks. It operates three 12-inch wafer fabs, four eight-inch wafer fabs, one six-inch wafer fab (fab 2) and two backend fabs (advanced backend fab 1 and 2). It also manages two eight-inch fabs at its subsidiaries, WaferTech, LLC in the United States and TSMC China Company Limited. Its exploratory work focuses on transistors and technologies, such as three dimensional (3D) structures, strained-layer complementary metal-oxide semiconductor (CMOS), high-mobility materials and 3D IC devices.