X0206 3 2019-10-25 0 0000704532 Onto Innovation Inc. ONTO 0001325550 Plisinski Michael P C/O ONTO INNOVATION INC. 16 JONSPIN ROAD WILMINGTON MA 01887 1 1 0 0 Chief Executive Officer No securities beneficially owned 0 D On October 25, 2019, the merger (the "Merger") of PV Equipment Inc., a subsidiary of the Issuer, with and into Rudolph Technologies Inc., pursuant to the Agreement and Plan of Merger, dated as of June 23, 2019, was completed. This report reflects the beneficial ownership of the Reporting Person at the time of completion of the Merger and does not include the securities of the Issuer acquired by the Reporting Person upon the completion of the Merger. The Reporting Person will file a Form 4 reflecting the Reporting Person's acquisition of securities of the Issuer in connection with the completion of the Merger. /s/ Robert A. Koch For: Michael P. Plisinski 2019-10-29