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:
Apr. 10, 2001
Filed:
Nov. 20, 1997
R. Michael Greig, Austin, TX (US);
Robert Stone, Austin, TX (US);
Mark K. Shackelford, Round Rock, TX (US);
Advanced Micro Devices, Sunnyvale, CA (US);
Abstract
A real-time hotspot detection system is disclosed. In a preferred embodiment, the real-time hotspot detection system of the present invention comprises a photolithography stepper that has been modified to output z-height focus data for each cell to a fault detection module of the present invention. After the entire wafer has been exposed by the stepper, the fault detection module computes the mean and standard deviation and/or other statistical data for the wafer data and compares the computed standard deviation with a predetermined limits for “normal” standard deviation, representative of a completely flat wafer having no hotspots thereon. If the computed standard deviation is outside the limits for the normal standard deviation, the fault detection module provides control signals to the stepper for halting the operation thereof and for generating an indication to the stepper operator, via a pole light associated with the stepper, that a failure has occurred. In addition, a wafer map showing the z-height data of the wafer that caused the failure may be displayed on a display associated with the module to enable a visual inspection to be performed and the cause of the hotspot to be more easily located.