SkyWater Technology Inc., the biggest maker of computer chips in Minnesota, said Tuesday the addition of a third clean room to its factory in Bloomington was ahead of schedule, with manufacturing equipment already being moved in.

The company announced the addition in October and said it was being paid for in part by the Pentagon, which for decades has been one of the largest end customers of chips made at the facility.

SkyWater is a contract manufacturer, building chips that are designed by other companies. Its new clean room, which is about the size of a football field and is four stories tall with two stories underground, will allow SkyWater to make chips that meet a military specification called "rad-hard," or hardened against the effects of radiation.

Such chips can be used for computers and other devices that operate in more difficult environments, including military settings, medical devices and in space.

Tom Sonderman, chief executive of SkyWater, said in an interview Monday that the earlier-than-expected completion of the construction of the clean room gives the company more breathing room for the installation, testing and ramping up of manufacturing equipment.

"By getting the facility done quicker, we're giving ourselves a bigger window to qualify the back-end portion of the process," he said.

SkyWater aims to begin producing chips from the new clean room by the end of 2021. By announcing that construction has ended, the company signals to customers that engineering and design work they put in for chips that will be built at SkyWater can begin sooner than anticipated.

"People can start designing on our program later this year," Sonderman said, referring to the mix of equipment and processes that will be available to build chips in the new clean room. "That allows the cycles of learning to begin sooner."

SkyWater received permission to begin occupying the new clean room about a week ago and began to move in chipmaking equipment. In mid-September, the ventilation system will be turned on to start to filter the air until the room is much cleaner than an operating room, aiming for a standard of a single micron-sized particle per cubic foot.

The addition is the first physical expansion of the factory since 1995, when a second clean room doubled the size of the plant, originally owned by Control Data Corp.

SkyWater, formed in 2017 by the Minneapolis investment firm Oxbow Industries LLC, bought the plant from Cypress Semiconductor, which remains a key customer of chips produced there.

Separately, Sonderman said production remained steady through the pandemic for SkyWater's two existing clean rooms as well as a new nanotube manufacturing process. The company notched contracts for chips that are used in several new medical devices used to combat COVID-19.

"Pretty true with a lot of semiconductor companies not tied to the smartphone, we've seen robust growth throughout this time frame," he said.