The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 27, 2005
Filed:
Oct. 22, 2003
Edward P. Maciejewski, Wappingers Falls, NY (US);
Phung T. Nguyen, Pleasant Valley, NY (US);
Edward J. Nowak, Essex Junction, VT (US);
Edward P. Maciejewski, Wappingers Falls, NY (US);
Phung T. Nguyen, Pleasant Valley, NY (US);
Edward J. Nowak, Essex Junction, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Disclosed is an on-chip test device for testing the thickness of gate oxides in transistors. A ring oscillator provides a ring oscillator output and an inverter receives the ring oscillator output as an input. The inverter is coupled to a gate oxide and the inverter receives different voltages as power supplies. The difference between the voltages provides a measurement of capacitance of the gate oxide. The difference between the voltages is less than or equal to approximately one-third of the difference between a second set of voltages provided to the ring oscillator. The capacitance of the gate oxide comprises the inverse of the frequency of the ring oscillator output multiplied by the difference between the voltages, less a capacitance constant for the test device. This capacitance constant is for the test device alone, and does not include any part of the capacitance of the gate oxide. The measurement of capacitance of the gate oxide is used to determine the thickness of the gate oxide.