Kla Tencor Corporation

Kla-tencor Technologies Corporation

Tencor Instruments

Hewlett-packard Company

Brian C Leslie

Akella V S Satya

Gustavo A Pinto

Robert Thomas Long

Keith B Wells

David Lewis Adler

Mehrdad Nikoonahad

David J Walker

Bin-Ming Benjamin Tsai

Armand P Neukermans

Ashok V Kulkarni

George J Kren

Kenneth P Gross

Ralph C Wolf

Neil W Richardson

Jiri Pecen

John L Vaught

Ralph T Johnson

Richard E Huff

Lee K Galbraith

Padma A Satya, Legal Representative

Hung Nguyen

Various methods, carrier media, and systems for detecting defects on a specimen using a combination of bright field channel data and dark field channel data are provided. One computer-implemented method includes combining pixel-level data acquired for the specimen by a bright field channel and a dark field channel of an inspection system. The method also includes detecting defects on the specimen by applying a two-dimensional threshold to the combined data. The two-dimensional threshold is defined as a function of a threshold for the data acquired by the bright field channel and a threshold for the data acquired by the dark field channel.

Methods and systems for detecting defects on a specimen using a combination of bright field channel data and dark field channel data

Disclosed is a method of inspecting a sample. The sample is scanned in a first direction with at least one particle beam. The sample is scanned in a second direction with at least one particle beam. The second direction is at an angle to the first direction. The number of defects per an area of the sample are found as a result of the first scan, and the position of one or more of the found defects is determined from the second scan. In a specific embodiment, the sample includes a test structure having a plurality of test elements thereon. A first portion of the test elements is exposed to the beam during the first scan to identify test elements having defects, and a second portion of the test elements is exposed during the second scan to isolate and characterize the defect.

Multiple directional scans of test structures on semiconductor integrated circuits

In an optical scanning system for detecting particles and pattern defects on a sample surface, a light beam is focused to an illuminated spot on the surface and the spot is scanned across the surface along a scan line. A detector is positioned adjacent to the surface to collect scattered light from the spot where the detector includes a one- or two-dimensional array of sensors. Light scattered from the illuminated spot at each of a plurality of positions along the scan line is focused onto a corresponding sensor in the array. A plurality of detectors symmetrically placed with respect to the illuminating beam detect laterally and forward scattered light from the spot. The spot is scanned over arrays of scan line segments shorter than the dimensions of the surface. A bright field channel enables the adjustment of the height of the sample surface to correct for errors caused by height variations of the surface. Different defect maps provided by the output of the detectors can be compared to identify and classify the defects. The imaging function of the array of sensors combines the advantages of a scanning system and an imaging system while improving signal/background ratio of the system.

Optical scanning system for surface inspection

A sample is inspected. The sample is scanned in a first direction with at least one particle beam. The sample is scanned in a second direction with at least one particle beam. The second direction is at an angle to the first direction. The number of defects per an area of the sample are found as a result of the first scan, and the position of one or more of the found defects is determined from the second scan. In a specific embodiment, the sample includes a test structure having a plurality of test elements thereon. A first portion of the test elements is exposed to the beam during the first scan to identify test elements having defects, and a second portion of the test elements is exposed during the second scan to isolate and characterize the defect.

Disclosed is a method of inspecting a sample. The sample is illuminated with an incident beam, thereby causing voltage contrast within structures present on the sample. Voltage contrast is detected within the structures. Information from the detected voltage contrast is stored, and position data concerning the location of features corresponding to at least a portion of the stored voltage contrast information is also stored. In a specific embodiment, the features represent electrical defects present on the sample. In another embodiment, the stored position data is in the form of a two dimensional map. In another aspect, the sample is re-inspected and the stored position data is used in analyzing data resulting from the re-inspection.

Methods and apparatus for generating spatially resolved voltage contrast maps of semiconductor test structures

Disclosed is a method of inspecting a sample. At least a portion of the sample is illuminated. Signals received from the illuminated portion are detected, and the detected signals are processed to find defects present on the sample. The processing of the detected signals is optimized, at least in part, based upon results obtained from voltage contrast testing. In one implementation, the illumination is an optical illumination. In another embodiment, the processing comprises automated defect classification, and setup of the automated classification is optimized using the results obtained from voltage contrast testing. In another implementation, the results relate to a probability that a feature present on the sample represents an electrical defect.

Methods and apparatus for optimizing semiconductor inspection tools

A method of locating particle and defect features on a periodically patterned surface uses multiple threshold intensity levels to identify features in the data stream produced by scanning the surface with a light beam and detecting the light scattered from the surface. High thresholds are assigned to regions of the surface with high background scatter, while low thresholds are assigned to regions of the surface with low background scatter. The scattered light is detected with a wide dynamic range detector producing high resolution 12-bit pixel data capable of resolving the smallest particles and defects of interest in low scatter regions, while avoiding saturation in high scatter regions. Periodic pattern features are removed from the data by mapping features from a plurality of periodically repeating die on the surface to a single die map and looking for overlapping features. Unique, nonoverlapping features are determined to correspond to particles and defects. In one embodiment, only a portion of all the die on the surface are mapped at one time to reduce the possibility of accidental overlap of particle and defect features.

Process for inspecting patterned wafers

An inspection apparatus for a light diffracting surface employs a planar array of individually addressable light valves for use as a spatial filter in an imaged Fourier plane of a diffraction pattern, with valves having a stripe geometry corresponding to positions of members of the diffraction pattern, blocking light from those members. The remaining valve stripes, i.e. those not blocking light from diffraction order members, are open for transmission of light. Light directed onto the surface, such as a semiconductor wafer, forms elongated curved diffraction orders from repetitive patterns of circuit features. The curved diffraction orders are transformed to linear orders by a Fourier transform lens. The linear diffraction orders from repetitive patterns of circuit features are blocked, while light from non-repetitive features, such as dirt particles or defects is allowed to pass through the light valves to a detector. Patterns of stripes can be recorded corresponding to the repetitive features of different integrated circuits. Different filters may be rapidly switched electronically in synchronization with a beam scanning a patterned surface inspecting different light diffracting patterns in different positions, allowing scattered or diffracted light from non-repetitive features to pass through the filter to a detector. A logical AND combination of two filters may be used so that two regions may be inspected in a single scan of the beam.

Adaptive spatial filter for surface inspection

A particle imager and method for imaging particles on surfaces of substrates. A surface is raster scanned by a collimated light beam and particles on the surface are detected by the scattered light caused by the particles. During a scan path the intensity of the scattered light is measured forming intensity traces and location addresses for the detected particles. Data from each scan path is stored in memory. The imager is pre-calibrated with a test wafer having light scattering marker points spaced at known positions thereon. Scanning the test wafer, a clock measures time elapsed from a start position to each marker point. The corresponding elapsed times and known address locations are stored in memory for reference during data collection.

Position location in surface scanning using interval timing between scan

Disclosed is a test probe [10] for testing a test device [not shown], also known as a device under test, while precisely controlling the force exerted by the test probe [10] on the test device. Included is a translation ring [18] as well as a carrier [12] formed to have at least a first side and a second side. The support means [12] is coupled to the translation ring [18]. Also included is at least one flexure pivot [14] for delivering a force to a test device; the flexure pivot [14] is coupled to the first side of the carrier. A membrane [16] is coupled to the second side of the carrier. Finally, at least one signal contact bump [24] is mounted on the membrane [16] for communicating an electric current between the test probe [10] and the test device [not shown].

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Cupertino, CA, United States of America

Brian C Leslie