EXHIBIT 21.1 UNITED STATES SUBSIDIARIES
Name State or Other Jurisdiction of Incorporation - ---- -------------------------------------------- Tencor Instruments California International Sales & Business, Inc. California KLA-Tencor Building Corporation California KLA-Tencor Disc Corporation California KLA-Tencor International Corporation California KLA-Tencor Instruments Klinnik California Corporation KLA-Tencor Management Corporation California KLA-Tencor (Thailand Branch) Corporation California VLSI Standards, Inc. California INTERNATIONAL SUBSIDIARIES KLA-Tencor (Cayman) Limited I Cayman Islands KLA-Tencor (Cayman) Limited II Cayman Islands KLA-Tencor (Cayman) Limited III Cayman Islands KLA-Tencor (Israel) Corporation Israel KLA-Tencor Holding Corporation 1987 Limited Israel KLA-Tencor Corporation 1992 Limited Israel KLA-Tencor Italy S.R.L. Italy KLA-Tencor Japan, Ltd. Japan KLA Instruments Sales Corporation U.S. Virgin Islands Tencor Foreign Sales Corporation U.S. Virgin Islands KLA-Tencor GmbH Germany Tencor Instruments GmbH Germany
KLA-Tencor France SARL France KLA Instruments France S.A. France KLA-Tencor Korea, Inc. Korea KLA-Tencor Limited United Kingdom KLA-Tencor (Malaysia) Sdn Bhd Malaysia KLA-Tencor (Singapore) PTE, Ltd. Singapore Tencor Instruments (Service) Limited United Kingdom VLSI Standards, KK Japan