Abstract: An automated, non-invasive method for classifying, detecting, and counting micropipes contained within silicon wafers, and generally any assortment of transparent wafers. Classifying, detecting, and counting micropipes takes place through the use of a data processing algorithm that incorporates information regarding: defect size; pit signature; area of pit signature when comparing a topography, specular, or scatter images; and detecting a tail within the standard pit signature. The method of the present invention teaches the development of a topography defect map, specular defect map, and scatter defect map for a complete analysis of the surface of a particular transparent wafer. Conventional detection, classification, and counting of micropipes involve characterization of micropipes in a manual fashion and rely upon an extremely invasive form of sample preparation.

Abstract: A process which addresses the problem of transient defects comprises first processing one or more test chips on a substrate to reveal one or more potential transient defects during subsequent processing of all of the chips on the substrate; identifying the exact locations of such potential transient defects on one or more chips of a silicon substrate; forming a file containing the coordinates of each potential transient defect on the chip; converting the file into a CAD image layer capable of displaying such potential transient defects; and displaying such potential transient defects superimposed over a CAD image of the actual circuit to permit visual inspection of the compound CAD image and to permit optional action to be taken in view of such potential transient defects.

Abstract: Disclosed are techniques for efficiently inspecting defects on voltage contrast test. In one embodiment, methodologies and test structures allow inspection to occur entirely within a charged particle system. In a specific embodiment, a method of localizing and imaging defects in a semiconductor test structure suitable for voltage contrast inspection is disclosed. A charged particle beam based tool is used to determine whether there are any defects present within a voltage contrast test structure. The same charged particle beam based tool is then used to locate defects determined to be present within the voltage contrast test structure. Far each localized defect, the same charged particle beam based tool may then be used to generate a high resolution image of the localized defect whereby the high resolution image can later be used to classify the each defect. In one embodiment, the defect's presence and location are determined without rotating the test structure relative to the charged particle beam.

Abstract: An inspection tool embodiment includes an illumination source for directing a light beam onto a workpiece to generate scattered light that includes the ordinary scattering pattern of the workpiece as well as light scattered from defects of the workpiece. The embodiment includes a programmable light selection array that receives light scattered from the workpiece and selectively directs the light scattered from defects onto a photosensor which detects the defect signal. Processing circuitry receives the defect signal and conducts surface analysis of the workpiece that can include the characterizing of defects of the workpiece. The programmable light selection arrays can include, but are not limited to, reflector arrays and filter arrays. The invention also includes associated surface inspection methods.

Abstract: A method for measuring a characteristic of a substrate, including directing an incident beam at an inspection grid of points on the substrate, receiving the reflected beam with a position sensitive detector, measuring the displacement of the reflected beam from its expected location, compiling a database of the displacement measurements, examining the database for effects of a pattern induced anomaly in the displacement measurements, producing an adjusted database, and deriving the characteristic of the substrate from the adjusted database. Thus, pattern induced errors from the displacement measurements are corrected. In this manner, problems with interpreting the reflection angles of a beam in substrate stress analysis equipment are overcome where distortions in the reflection angles are caused by deposition patterns on the substrates.

Abstract: A method of determining the actual properties of a film stack. An incident beam of light is directed towards the film stack, such that the incident beam of light is reflected from the film stack as a reflected beam of light. The actual properties of the reflected beam of light are measured, and properties of the film stack are estimated. A mathematical model of the film stack is solved with the estimated properties of the film stack to yield theoretical properties of the reflected beam of light. The theoretical properties of the reflected beam of light are compared to the actual properties of the reflected beam of light to yield a cost function. The estimated properties of the film stack are iteratively adjusted and the mathematical model is iteratively solved until the cost function is within a desired tolerance. The estimated properties of the film stack are reported as the actual properties of the film stack.

Abstract: A double-sided optical inspection system is presented which may detect and classify particles, pits and scratches on thin film disks or wafers in a single scan of the surface. In one embodiment, the invention uses a pair of orthogonally oriented laser beams, one in the radial and one in the circumferential direction on both surfaces of the wafer or thin film disk. The scattered light from radial and circumferential beams is separated via their polarization or by the use of a dichroic mirror together with two different laser wavelengths.

Abstract: A system and method for reducing peak power of a laser pulse and reducing speckle contrast of a single pulse comprises a plurality of elements oriented to split and delay a pulse or pulses transmitted from a light emitting device. The design provides the ability to divide the pulse into multiple pulses by delaying the components relative to one another. Reduction of speckle contrast entails using the same or similar components to the power reduction design, reoriented to orient received energy wherein angles between the optical paths are altered such that the split or divided light energy components strike the target at different angles or different positions. An alternate embodiment for reducing speckle contrast is disclosed wherein a single pulse is passed in an angular orientation through a grating to create a delayed portion of the pulse relative to the leading edge of the pulse.

Abstract: Spatial filtering is disclosed that improves the signal to noise ration of a sample inspection system of the type having a detector and collection optics that receive radiation scattered from a point on a sample surface and direct the scattered radiation toward the detector. The spatial filtering may screen the detector from substantially all of the forward-scattered radiation from back-scattered radiation that is scattered in a at an elevation angle less than about 45° with respect to a normal to the surface. Forward scattered noise is screened from the detector while backscattered signal reaches the detector. Programmable spatial filters may be used to selectively block scattered noise due to surface roughness while transmitting scattered signal due to surface defects.

Abstract: One embodiment disclosed relates to an apparatus for inspecting or revieiwing a mask or reticle. The apparatus includes at least an optical system, a converter plate, and an electron system. The optical system projects an optical illumination onto the mask. The optical signal from the mask is received by the converter plate. The converter plate transforms the optical signal to a corresponding electron signal. The electron signal is imaged by the electron system.

Abstract: A reduced size catadioptric objective and system is disclosed. The objective may be employed with light energy having a wavelength in the range of approximately 190 nanometers through the infrared light range. Elements are less than 100 mm in diameter. The objective comprises a focusing lens group configured to receive the light energy and comprising at least one focusing lens. The objective further comprises at least one field lens oriented to receive focused light energy from the focusing lens group and provide intermediate light energy. The objective also includes a Mangin mirror arrangement positioned to receive the intermediate light energy from the field lens and form controlled light energy for transmission to a specimen. The Mangin mirror arrangement imparts controlled light energy with a numerical aperture in excess of 0.65 and up to approximately 0.90, and the design may be employed in various environments.

Abstract: An inspection system for detecting anomalies on a substrate. The inspection system has a sensor array for generating image data. A first high speed network is coupled to the sensor array and receives and communicates the image data. An array of process nodes is coupled to the first high speed network, and receives and processes the image data to produce anomaly reports. Each process node has an interface card coupled to the first high speed network, that receives the image data from the first high speed network and formats the image data according to a high speed interface bus protocol. The interface card sets a register indicating whether a predetermined amount of image data has been stored in a memory, and the process node reads the register to determine whether the predetermined amount of image data has been stored in the memory, and initiates image processing when the register indicates that the predetermined amount of image data has been stored in the memory.

Abstract: An overlay mark for determining the relative position between two or more successive layers of a substrate or between two or more separately generated patterns on a single layer of a substrate is disclosed. The overlay mark includes a plurality of working zones, which are used to calculate alignment between a first and a second layer of the substrate or between a first and a second pattern on a single layer of the substrate. Each of the working zones is positioned within the perimeter of the mark. Each of the working zones represents a different area of the mark. The working zones are configured to substantially fill the perimeter of the mark such that the combined area of the working zones is substantially equal to the total area of the mark.

Abstract: A surface of an insulating substrate is charged to a target potential. In one embodiment, the surface is flooded with a higher-energy electron beam such that the electron yield is greater than one. Subsequently, the surface is flooded with a lower-energy electron beam such that the electron yield is less than one. In another embodiment, the substrate is provided with the surface in a state at an approximate initial potential above the target potential. The surface is then flooded with charged particle such that the charge yield of scattered particles is less than one, such that a steady state is reached at which the target potential is achieved. Another embodiment pertains to an apparatus for charging a surface of an insulating is substrate to a target potential.

Abstract: Before the diffraction from a diffracting structure on a semiconductor wafer is measured, where necessary, the film thickness and index of refraction of the films underneath the structure are first measured using spectroscopic reflectometry or spectroscopic ellipsometry. A rigorous model is then used to calculate intensity or ellipsometric signatures of the diffracting structure. The diffracting structure is then measured using a spectroscopic scatterometer using polarized and broadband radiation to obtain an intensity or ellipsometric signature of the diffracting structure. Such signature is then matched with the signatures in the database to determine the grating shape parameters of the structure.

Abstract: One embodiment disclosed relates to an automated process for focusing a charged-particle beam in an apparatus onto an area of a substrate. A focusing parameter of the apparatus is set to a value, and intensity data is acquired from the area. The foregoing setting and acquiring steps are repeated for a range of values for the focusing parameter. A focusing sharpness measure is computed for each value of the focusing parameter based on noise in the acquired intensity data, and an in-focus value is determined for the focusing parameter based on the computed focusing sharpness measures. The focusing parameter of the apparatus may be, for example, an objective lens current, or a substrate bias voltage. The computation of the noise-based focusing sharpness measure may involve generating shifted or interleaved signals and calculating correlations between these signals. The focusing may be advantageously performed on an area lacking substantial edge information.

Abstract: A reduced size catadioptric objective and system is disclosed. The objective may be employed with light energy having a wavelength in the range of approximately 190 nanometers through the infrared light range. Elements are less than 100 mm in diameter. The objective comprises a focusing lens group configured to receive the light energy and comprising at least one focusing lens. The objective further comprises at least one field lens oriented to receive focused light energy from the focusing lens group and provide intermediate light energy. The objective also includes a Mangin mirror arrangement positioned to receive the intermediate light energy from the field lens and form controlled light energy for transmission to a specimen. The Mangin mirror arrangement imparts controlled light energy with a numerical aperture in excess of 0.65 and up to approximately 0.90, and the design may be employed in various environments.

Abstract: A method and apparatus for inspection and review of defects is disclosed wherein data gathering is improved. In one embodiment, multiple or segmented detectors are used in a particle beam system.

Abstract: Faster and more accurate techniques for displaying images are described. The techniques can be applied in various applications that include semiconductor fabrication processes. The invention uses preprocessed images to generate a user-selected image in order to increase the speed of image processing. The invention displays the pixels forming an image using grayscale shading in order to improve the accuracy of displaying the patterns used in photolithography processes. The techniques of the present invention can be used to display images that represent lithography patterns stored within memory devices or to display images captured by inspection or metrology devices.

Abstract: An x-ray metrology system includes an e-beam generator to cause a test sample to emit x-rays, x-ray optics for focusing the x-rays, and an x-ray imager to generate an image of the test sample from the focused x-rays. Because the x-ray imager provides a direct representation of the x-ray emission characteristics of the test sample, the resolution of a measurement taken using such a sensor is limited only by the resolution of the sensor (and any focusing optics), rather than by the amount of e-beam spread in the thin film. The x-ray imaging can be performed for object planes at the test sample that are not parallel to the test sample, thereby allowing vertical dimension data to be accurately generated by the x-ray imaging system.