Hseb Dresden Gmbh

Aoti Operating Company, Inc

Accent Optical Technologies Nanometrics, Inc.

Unity Semiconductor Corporation

Bernd Srocka

Ralf Langhans

Marko Döring

Benno Orschel

Stanislas Flon

Christine Schmidt

Hagen Raue

Jan Helm

Arman Siahkali

A method and assembly for determining the thickness of layers of a sample stack influencing the intensity of reflected light from a light source. The thickness is determined from the intensity detected by an array detector with a plurality of detector elements in lines and columns. The detector comprises a plurality of sections in the form of parallel stripes, the stripes detecting the light reflected by the sample stack of layers simultaneously. Light of one selected wavelength range only is detected by each of the plurality of sections of the detector. The image of the sample stack on the detector or of the parallel stripes is moved in a direction perpendicular to the longitudinal direction of the parallel stripes such that each point of the sample stack is detected at least once in each of the different wavelength ranges.

Method and assembly for determining the thickness of a layer in a sample stack

A method for optically measuring height profiles of surfaces, in which an image of the height profile is recorded using an optical recording system, is characterized in that the image is a differential interference contrast image and height gradients within the height profile are represented by intensity gradients, which are quantitatively or qualitatively evaluatable. The surfaces can have structures having a defined profile, in which intensity gradients in the differential interference contrast image, which assume, within a specified tolerance and within a specified range, a value which deviates from a predetermined value or assume a selected value from within a specified tolerance and within a specified range, indicate a defect.

Measurement method for height profiles of surfaces using a differential interference contrast image

An apparatus for inspecting flat objects, in particular wafers, containing an object holder; a camera arrangement having a camera for recording an image of at least one part of the object; and a drive arrangement for producing a relative movement between the camera arrangement and the object from a first recording position to at least one further recording position; is characterized in that the camera arrangement has at least one further camera; the object areas imaged in different cameras are at least partially different, wherein all cameras together simultaneously record only part of the total inspection area of the object; and each object point of the entire inspection area can be imaged at least once in one of the cameras as a result of the relative movement between the camera arrangement and the object, as produced with the drive arrangement.

Inspection apparatus

A method for determining the thickness of a layer in a sample stack of at least two layers with an assembly comprising a light source for illuminating a stack of layers and a detector for detecting light reflected by the stack of layers in a defined first wavelength range, the method comprises a first step of obtaining a calibration curve by the calibrating steps of providing two or more reference stacks of layers, where each layer of the reference stacks has a known thickness, the same material as the sample stack and the layers occur in the same order as in the sample stack; illuminating the reference stacks with light from the light source; and detecting the intensity of light reflected by the reference stacks with the detector in the first wavelength range. Further steps of the method comprise illuminating the sample stack of layers with light from the light source; detecting the intensity of the light reflected by the sample stack of layers with the detector in the first wavelength range; and determining the thickness of the layer comprised in the sample stack of layers from the intensity detected by the detector by means of the calibration curve. The method is characterized in that further calibration curves are obtained of reference stacks, where the thickness of another, different layer is known also, thereby providing a first series of calibration curves in the first wavelength range; a second plurality of calibration curves is obtained in the same way as the first series of calibration curves for a further wavelength range; and the thickness of the layer of the sample stack is determined from the intensity detected by the detector by means of the first and second series of calibration curves.

An arrangement for optically detecting buried layers of flat objects having a plurality of layers, in particular wafers, containing a radiation source for illuminating the surface of the object at an angle; a polarization filter arranged in the beam path; and a detector for detecting radiation reflected by the surface of the object or transmitted by the object; is characterized in that that layer of the object which is closest to the radiation source at least partially transmits the radiation from the radiation source; the polarization filter transmits only radiation which is polarized parallel to the plane of incidence; and the surface of the object is illuminated at the Brewster angle. The surface of the object is preferably illuminated with unpolarized radiation and the polarization filter is arranged in the beam path between the surface of the object and the detector.

Method for detecting buried layers

The invention relates to an arrangement for analyzing an at least partially reflective surface of a wafer or other objects, containing a holder for holding the object; an inspection arrangement arranged at a distance in the region in front of the surface to be analyzed; and a measurement arrangement for determining the distance and/or inclination of the surface for the inspection arrangement; characterized be a radiation source, the radiation of which is directed towards the surface to be analyzed at an angle; and a spatially resolving detector for receiving the radiation from the radiation source that is reflected from the surface to be analyzed, wherein the radiation source and the detector are arranged outside the region necessary for the inspection between the inspection arrangement and the surface to be analyzed.

Inspection arrangement

A method for inspecting wafers or other flat objects having an object surface, comprises the steps of: providing a camera assembly with a camera for recording images of said object surface or portions of said object surface during an exposure time which is limited by a shutter; generating a continuous relative movement of said camera assembly and said object without interruption, whereby a movement blur of said image during said exposure time is caused; continuously illuminating said object with an illuminance which is controlled to remain at the same value; and recording one or more images of at least one of said portions of said object surface with said camera; defining a movement blur which is acceptable for an analysis of said image wherein said exposure time is smaller than a time causing said acceptable movement blur; and performing said analysis of said image.

Inspection assembly

A Method for inspecting flat objects, especially wafers, with an object surface, comprises the steps of: scanning a digital image with a plurality of image points of said object surface with color- or grey values for each of said image points; detecting defects on said object surface by comparing said scanned digital image to a digital reference image; defining and selecting corresponding portions in said scanned digital image and in the digital reference image; determining a representative color- or grey value for each of said selected portions; calculating a compare value from said representative color- or grey value of said scanned digital image of a portion and a representative color- or grey value of said digital reference image of the same portion; and correcting each image point of said scanned digital image with a correction value determined from said compare value of step (e).

Inspection method with color correction

An inspection system for flat objects, especially wafers and dies, including: a handling system for loading objects into the inspection system; a sensor assembly for receiving images or measuring values of the object surface or parts of the object surface; a driving assembly for generating a relative movement between the objects and the sensor assembly, where a movement is effected between objects relative to the sensor assembly along a first trajectory; wherein at least one further sensor assembly is provided, and the driving assembly is adapted to generate a further relative movement, where a movement of different objects relative to the sensor assembly can be generated on at least a second trajectory in order to allow at least two objects to be treated simultaneously.

Inspection system

The invention relates to a method for determining a characteristic of a semiconductor sample forming a surface. The method comprises the steps: simultaneously illuminating an area on the surface of a semiconductor sample with superimposed exciting light beams with a plurality of wavelengths, modulating the light beam of the different wavelengths with the same frequency, but different phases, selecting a modulation function and its phases in such a way, that the sum of the photon fluxes of all light beams at all times lies within a tolerance range, the tolerance range being considerably smaller than the sum of all photon fluxes, simultaneously phase-dependent measuring of the components of the surface photo voltage caused by the different light beams and determining the characteristic of the semiconductor sample from the relationships between the components and the respective wavelengths. Furthermore a device for carrying out such a method is described.

Method and device for determining a characteristic of a semiconductor sample

For determining the dependence of a first measuring quantity (Y) on a second measuring quantity (P) the second measuring quantity (P) is periodically modified with a frequency (f ). The first measuring quantity (Y) changing accordingly is measured. From the obtained measuring signal of the first measuring quantity (Y) the components of the first measuring quantity (Y) are determined with at least a plurality of frequencies. From the components thus determined the first measuring quantity (Y) is reconstructed for at least a plurality of values of the second measuring quantity (P) by signal processing.

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Berlin, Germany

Bernd Srocka