Semitool Inc. confirmed this week that it is laying off about 100 workers – including 37 in Libby.

With about 800 workers at the Semitool plants in Kalispell and Libby, the layoffs will affect under 13 percent of its Montana work force. Workers were told to consider the layoffs permanent.

Semitool, the third-largest employer in Flathead County, is a leading manufacturer of wafer processing equipment for the semiconductor industry. Its global headquarters are in Kalispell.

Human resources manager Vicki Billmayer said she and two Semitool executives, chief operating officer Larry Murphy and vice president of operations Jim Wright, delivered the news on Monday and Tuesday.

“It really was across the board,” Billmayer said.

Neither specific departments nor seniority levels were targeted, she said. “We always work on performance-based” criteria when making layoff decisions.

The local job cuts are part of the company’s plans to lay off about 170 workers worldwide out of its total work force of 1,300. Semitool has locations in Taiwan, Korea, China, Japan, Singapore, England and Austria and employs about 100 outside sales professionals in California, Arizona, Texas, Minnesota and on the East Coast.

Semitool designs, manufactures and supports highly engineered chemical processing equipment used in the fabrication of semiconductor devices.

“The worldwide economic downturn has impacted Semitool just like it has everybody else, and unfortunately we’ve had to do some reduction in force,” the company announced in a prepared statement Monday morning.

Semitool was founded in 1979 in Kalispell by Ray Thompson. Today, Thompson is chief executive officer and chairman of the board for Semitool.

(Nancy Kimball is a reporter for the Daily Inter Lake in Kalispell).