Credence Systems Corporation

Dcg Systems Gmbh

Nptest, Inc.

Mark Alan Thompson

Theodore R Lundquist

Erwan Le Roy

William B Thompson

Patricia Le Coupanec

Lokesh Johri

Ketan Shah

Catherine Kardach

Tamayasu Anayama

An improved method, apparatus, and control/guiding software for localizing, characterizing, and correcting defects in integrated circuits, particularly open or resistive contact/via defects and metal bridging defects, using FIB technology. An apparatus for identifying an abnormal discontinuity in a contact/via in an integrated circuit comprising a focused ion beam system to scan the ion beam over the contact/via to do remove or deposit via material, a detector to collect a secondary particle signal from the contact/via material that gets removed, a sub-system for storing the secondary particle signal from the contact/via in time as well as x-y scan position, a sub-system for correlating secondary particle signals and identifying discontinuities in the correlated secondary particle signals, a sub-system for optimizing the display of the abnormal discontinuity; and a computer to implement software aspects of the system.

FIB based open via analysis and repair

The backside navigation method of the present invention includes milling a fiducial opening through the substrate of an integrated circuit. The milling process is stopped when the fiducial opening reaches the bottom of a trench isolation structure. The trench isolation structure delineated by the fiducial opening may be imaged and registered to a computer aided design layout image to achieve sub-micron navigation resolution.

Method and system for integrated circuit backside navigation

A method for utilizing interference fringe patterns generated when milling a trench through a semiconductor substrate by a method such as FIB milling, to determine and optimize the thickness uniformity of the trench bottom. The interference fringes may be mapped and the mapping used to direct the FIB milling to those regions which are thicker to correct observed non-uniformities in the trench floor thickness by varying the pixel dwell time across the milled area. The interference fringe mapping may be used to develop computerized contour lines to automate the pixel dwell time variations as described above, for correcting non-uniformities in the trench floor thickness. The method may be applied to applications other than trench formation for backside editing, such as monitoring progress in forming a milled object.

Method and apparatus for addressing thickness variations of a trench floor formed in a semiconductor substrate

Apparatus and method for exposing a selected feature of an integrated circuit device such as a selected portion of the metallization layer, from the backside of the integrated circuit substrate without disturbing adjacent features of the device such as the active semiconductor regions. This is performed using an FIB (focused ion beam) etching process in conjunction with observation by an optical microscope to form a trench through the substrate. The floor of the trench is formed so as to be as smooth and planar as possible, thereby preventing undesirable exposure of the underlying active regions through any unknown or undesired cavity caused by scratches or pits or a deeper than desired sidewall. The smoothness and planarity of the floor of the trench is established by, prior to forming the trench, removing any surface defect initially present by using an FIB etching without use of assist gas to eliminate most scratches or impurities on the surface of the silicon, followed by removal of implanted ions using a gas-injected assisted FIB etch. Then the actual trench is formed using an assisted etch using a more aggressive injected gas.

Method and apparatus for forming a cavity in a semiconductor substrate using a charged particle beam

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Austin, TX, United States of America

Mark Alan Thompson