1 Exhibit 23.3 May 4, 2000 Axcelis Technologies, Inc. (formerly known as Eaton Semiconductor Equipment Inc.) 55 Cherry Hill Drive Beverly, Massachusetts 01915 Dear Sir or Madam: In conformity with Regulation Section 230.438 of the Securities Act of 1933, I hereby consent to be named a director of Axcelis Technologies, Inc. (formerly known as Eaton Semiconductor Equipment Inc.) in its registration statement on Form S-1 and related documents. I understand and consent to the filing of these documents with the United States Securities and Exchange Commission. Sincerely, /s/ Mary G. Puma - --------------------------------------- Name: Mary G. Puma ---------------------------------- Title: Officer and Nominee for Director --------------------------------- Date: 5/4/2000 ----------------------------------