MEMC Electronic Materials Inc. laid off 90 employees this week from its O’Fallon, Mo., production site, a company spokesperson said Thursday. The company, which also has its headquarters in O’Fallon, said the cuts were necessary to better align employment with production experienced in the last year, the company said. Various positions were affected, from salaried staff to maintenance. The company now employs about 5,300 people worldwide, with about 915 in O’Fallon. MEMC makes silicon wafers used in electronic applications and solar batteries.