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. 14, 1987
Filed:
Oct. 18, 1984
Simon C Garth, Cambridge, GB;
William C Nixon, Cambridge, GB;
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
Electron detector apparatus and method for detecting secondary electrons released from a body, of particular utility in testing integrated circuits in an operational state. The apparatus utilizes a magnetic lens having an axis of symmetry, for producing a magnetic field that progressively weakens along the axis, so that the secondary electrons travel through the magnetic lens in progressively elongated helical paths and approach an electron retarding means, for example a planar grid, at approach angles to the direction of the axis such that their approach speeds along the axis are substantially equal to their actual speeds. The secondary electrons are collected after passage through the retarding means. Alternatively, the secondary electrons may be directed through a magnetic lens having an axis of symmetry to focus them at a small region at one end of the lens on which a part spherical electron retarding electrode is centered, such that the focussed secondary electrons proceed along radial paths to the retarding electrode, such that their approach speeds are substantially equal to their actual speeds.