Applied Materials, Inc.

Schlumberger Technologies, Inc.

Chiwoei Wayne Lo

Christopher G Talbot

Xinrong Jiang

Kenichi Kanai

William K Lo

Li Wang

Daniel N Bui

Pierre Perez

Harry S Gallarda

Luis Camilo Orjuela

Adam Rhoads

Mariel Stoops

A multi-charged particle beam tool for semiconductor wafer inspection or lithography includes an array of electron beam columns, each having its own electron or ion source. The objective lenses of the various electron beam columns, while each has its own pole piece, share a common single magnetic coil which generates a uniform magnetic field surrounding the entire array of electron beam columns. This advantageously improves the spacing between the beams while providing the superior optical properties of a strong magnetic objective lens. When used as an inspection tool, each column also has its own associated detector to detect secondary and back-scattered electrons from the wafer under inspection. In one version the gun lenses similarly have individual pole pieces for each column and share a common magnetic coil.

Method and apparatus for multiple charged particle beams

A method of detecting defects in a patterned substrate includes positioning a charged-particle-beam optical column relative to a patterned substrate, the charged-particle-beam optical column having a field of view (FOV) with a substantially uniform resolution over the FOV; operating the charged-particle-beam optical column to acquire images of a region of the patterned substrate lying within the FOV by scanning the charged-particle beam over the patterned substrate; and comparing the acquired images to a reference to identify defects in the patterned substrate.

Detection of defects in patterned substrates

One embodiment of the present invention is a method of detecting defects in a patterned substrate, including: (a) positioning a charged-particle-beam optical column relative to a patterned substrate, the charged-particle-beam optical column having a field of view (FOV) with a substantially uniform resolution over the FOV; (b) operating the charged-particle-beam optical column to acquire images of a region of the patterned substrate lying within the FOV by scanning the charged-particle beam over the patterned substrate; and (c) comparing the acquired images to a reference to identify defects in the patterned substrate.

Defects in a patterned substrate are detected by inspection with a charged particle beam inspection tool which generates an image of a portion of the patterned substrate and compares the image with a reference in order to identify any defects in the patterned substrate. Parameters of the tool are optimized to improve image uniformity and contrast, particularly voltage contrast. Prior to imaging an area of the substrate, the tool charges an area surrounding the image area to eliminate or reduce the effects caused by asymmetrical charging in the surrounding area. The tool alternates between charging the surrounding area and imaging the image area to produce a plurality of images of the image area, which are then averaged. The result is a highly uniform image with improved contrast for accurate defect detection.

Voltage contrast method and apparatus for semiconductor inspection using low voltage particle beam

Methods and apparatus are provided for inspecting a patterned substrate, comprising: preparing a reference image and a test image, extracting features from the reference image and extracting features from the test image, matching features of the reference image and features of the test image; and comparing features of the reference image and of the test image to identify defects. Embodiments include apparatus for inspecting patterned substrates, computer-readable media containing instructions for controlling a system having a processor for inspecting patterned substrates, and computer program products comprising a computer usable media having computer-readable program code embodied therein for controlling a system for inspecting patterned substrates. The images can be electron-beam voltage-contrast images.

Feature-based defect detection

Defects in a patterned substrate are detected by positioning a charged-particle-beam optical column relative to a patterned substrate, the charged-particle imaging system having a field of view (FOV) with a substantially uniform resolution over the FOV; operating the charged-particle-beam optical column to acquire images over multiple subareas of the patterned substrate lying within the FOV by scanning a charged-particle beam over the patterned substrate while maintaining the charged-particle-beam optical column fixed relative to the patterned substrate; and comparing the acquired images to a reference to identify defects in the patterned substrate. The use of a large-FOV imaging system with substantially uniform resolution over the FOV allows acquisition of images over a wide area of the patterned substrate without requiring mechanical stage moves, thereby reducing the time overhead associated with mechanical stage moves. Multiple columns can be ganged together to further improve throughput.

Apparatus for detecting defects in patterned substrates

A method of testing a semiconductor structure such as a finished or part-finished semiconductor wafer, a die on such a wafer, part of such a die, or even one functional element (e.g. a transistor or memory cell) of such a die. The method includes the steps of charging at least a part of the semiconductor structure; applying an electric field perpendicular to a surface of the structure while charging so as to determine charging potential and polarity (i.e. charging either positively or negatively); interrogating the structure including the charged part with a charged particle beam, such as an electron beam, so as to obtain voltage contrast data for the structure; and analyzing the data to determine the functionality of the element. Apparatus according to the invention for testing semiconductor structures, includes: a system for applying charge to at least part of the semiconductor structure, such as an electron beam, flood gun or mechanical probe; an electric field generator, typically an electrode spaced from the surface of the structure, which applies an electric field perpendicular to a surface of the structure so as to determine the potential and polarity of the charge applied to the element (i.e. positive or negative charge); a charged particle beam device such as an electron beam for interrogating the charged element; and a detector such as a secondary electron detector which obtains voltage contrast data from the structure on interrogation with the charged particle beam.

Methods and apparatus for testing semiconductor and integrated circuit structures

Voltage contrast method for semiconductor inspection using low voltage particle beam

Defects in a patterned substrate are detected by positioning a charged-particle-beam optical column relative to a patterned substrate, the charged-particle imaging system having a field of view (FOV) with a substantially uniform resolution over the FOV; operating the charged-particle-beam optical column to acquire images over multiple subareas of the patterned substrate lying within the FOV by scanning a charged-particle beam over the patterned substrate while maintaining the charged-particle-beam optical column fixed relative to the patterned substrate; and comparing the acquired images to a reference to identify defects in the patterned substrate. The use of a large- FOV imaging system with substantially uniform resolution over the FOV allows acquisition of images over a wide area of the patterned substrate without requiring mechanical stage moves, thereby reducing the time overhead associated with mechanical stage moves. Multiple columns can be ganged together to further improve throughput.

Method of detecting defects in patterned substrates

A stage assembly for holding a work-piece in a charged particle microscopy system includes a magnetic motor (e.g., brushless linear servo motor) for driving an X-platform riding on a base along the X axis, a non-magnetic linear motor (e.g., piezoelectric motor) for driving a Y-platform riding on the X-platform along the Y axis, and a non-magnetic rotary motor (e.g., piezoelectric motor) for rotating a rotary platform over the Y-platform, wherein the duty cycle of the magnetic motor is substantially greater than the duty cycle of the non-magnetic linear and rotary motors. This along with the particular arrangement of the motors and the platforms yields a compact, durable, and vacuum compatible stage which has minimal mechanical vibrations, minimal interference with the charged particle microscope, minimal particle generation, and high speed area coverage.

Stage for charged particle microscopy system

Methods of inspecting a microstructure comprise: applying charged particles to the wafer to negatively charge up the wafer over a region having contact or via holes, scanning a charged-particle beam over the region while detecting secondary particles so as to produce a detector signal, determining from the detector signal an apparent dimension of a contact hole, and comparing the apparent dimension of the contact hole with reference information to identify a defect. The reference information can be a conventional voltage-contrast image or can be design data indicating expected physical size of the contact hole and expected electrical connectivity of material within or beneath the contact hole. The wafer can be charged up by directing a flood of electrons toward a surface of the wafer and/or by controlling potential of an energy filter so as to direct secondary electrons back to the wafer while directing a charged-particle beam at the wafer. Other methods of inspecting a microstructure comprise charging up a microstructure, interrogating the microstructure with a charged-particle beam to obtain apparent dimensional information for a feature of the microstructure, and comparing the apparent dimensional information with reference information about the microstructure to identify a defect. Apparatus for inspecting semiconductor wafers and other microstructures are also disclosed, as are computer program products comprising a computer usable media having computer-readable program code embodied therein for controlling a charged-particle-beam system for inspecting a microstructure.

Microstructure defect detection

A method for detecting electrical defects in a semiconductor wafer, includes the steps of: a) applying charge to the wafer such that electrically isolated structures are raised to a voltage relative to electrically grounded structures; b) obtaining voltage contrast data for at least a portion of the wafer containing such structures using an electron beam; and c) analyzing the voltage contrast data to detect structures at voltages different from predetermined voltages for such structures. Voltage contrast data can take one of a number of forms. In a simple form, data for a number of positions on a line scan of an electron beam can be taken and displayed or stored as a series of voltage levels and scan positions. Alternatively, the data from a series of scans can be displayed as a voltage contrast image. Analysis can be achieved by comparison of one set of voltage contrast data, for example voltage contrast data from one die on a wafer, with one or more other such sets, for example voltage contrast data for corresponding structures on one or more preceding dice, so as to determine differences therebetween.

Method and apparatus for detecting defects in wafers

An optical system for a particle beam device such as an electron microscope, e-beam device or FIB device, including a particle beam column having an optical axis along which a beam of particles is projected and an apertured plate positioned in the column having an aperture which is coaxial with the optical axis, the plate being moveable in a direction which is parallel to the optical axis.

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Campbell, CA, United States of America

Chiwoei Wayne Lo