X0306 4 2021-11-17 0001102934 CMC Materials, Inc. CCMP 0001752950 Thorp Eleanor Kate C/O CMC MATERIALS, INC. 870 N. COMMONS DRIVE AURORA IL 60504 1 VP, Human Resources Common Stock 2021-11-17 4 A 0 895 0 A 5625.664 D Represents settlement of performance share units ("PSUs") in shares of common stock for the three-year performance period beginning October 1, 2018 and ending September 30, 2021, granted under the CMC Materials, Inc. 2012 Omnibus Incentive Plan, which are exempt from liability under Section 16(b) of the Securities Exchange Act pursuant to Rule 16b-3(d). /s/ H. Carol Bernstein (Power of Attorney) 2021-11-17