Taiwanese firm GlobalWafers Co. has finalized its acquisition of SunEdison Semiconductor, the O’Fallon, Mo.-based maker of silicon wafers for the electronics industry.

GlobalWafers and SunEdison Semiconductor announced the $683 million sale, including the Missouri company’s debt, in August.

GlobalWafers said the deal would give the company more reach into the markets of South Korea and the European Union.

“Our enterprise footprint of 17 operation sites located in 10 countries is strategically positioned in all regions to support our customers more effectively,” said Doris Hsu, chairperson and CEO of GlobalWafers.

SunEdison Semiconductor grew out of a Monsanto affiliate founded in 1959. The company still uses the plant Monsanto built in St. Charles County almost 60 years ago to make some of the first silicon wafers that are the building blocks of computers, cellphones and other electronics.