EXHIBIT 99.1 CERTIFICATION PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 (SUBSECTIONS (a) AND (b) OF SECTION 1350, CHAPTER 63 OF TITLE 18, UNITED STATES CODE) Pursuant to section 906 of the Sarbanes-Oxley Act of 2002 (subsections (a) and (b) of section 1350, chapter 63 of Title 18, United States Code), each of the undersigned officers of Zygo Corporation, a Delaware corporation (the "Company"), does hereby certify with respect to Amendment No. 1 to the Annual Report of the Company on Form 10-K/A for the year ended June 30, 2002 as filed with the Securities and Exchange Commission (the "10-K/A Report") that: (1) the 10-K/A Report fully complies with the requirements of section 13(a) and 15(d) of the Securities Exchange Act of 1934; and (2) the information contained in the 10-K/A Report fairly presents, in all material respects, the financial condition and results of operations of the Company as of and for the periods presented therein. Dated: July 14, 2003 /s/ J. Bruce Robinson - --------------------------------- J. Bruce Robinson Chairman, President, and Chief Executive Officer of Zygo Corporation Dated: July 14, 2003 /s/ Richard M. Dressler - --------------------------------- Richard M. Dressler Vice President, Finance, Chief Financial Officer of Zygo Corporation -1-