Abstract: Systems and methods for processing phase maps acquired using interferometer wafer geometry tools are disclosed. More specifically, instead of performing phase unwrapping first and then analyze the unwrapped data in a height domain, systems and methods in accordance with the present disclosure operate in a curvature domain without having to perform any phase unwrapping.

Abstract: A semiconductor measuring tool has a folding mirror configuration that directs a light beam to pass the same space multiple times to reduce the size and footprint. Furthermore, the folding mirrors may reflect the light beam at less than forty-five degrees; thereby allowing for smaller folding mirrors as compared to the prior art.

Abstract: Interferometer systems and methods for providing improved defect detection and quantification are disclosed. The systems and methods in accordance with the present disclosure may detect surface defects on patterned or bare wafer surfaces and subsequently quantify them. In certain embodiments in accordance with the present disclosure, amplitude maps of the wafer surfaces are obtained and are utilized in addition/alternative to phase maps for wafer surface feature detection. Furthermore, local one-dimensional and/or two-dimensional unwrapping techniques are also disclosed and are utilized in certain embodiments in accordance with the present disclosure to provide height and depth information of the detected defects, further improving the detection capabilities of the measurement systems.

Abstract: A semiconductor measuring tool has a folding mirror configuration that directs a light beam to pass the same space multiple times to reduce the size and footprint. Furthermore, the folding mirrors may reflect the light beam at less than forty-five degrees; thereby allowing for smaller folding mirrors as compared to the prior art.

Abstract: A semiconductor measuring tool has a folding mirror configuration that directs a light beam to pass the same space multiple times to reduce the size and footprint. Furthermore, the folding mirrors may reflect the light beam at less than forty-five degrees; thereby allowing for smaller folding mirrors as compared to the prior art.

Abstract: A calibration wafer and a method for calibrating an interferometer system are disclosed. The calibration method includes: determining locations of the holes defined in the calibration wafer based on two opposite intensity frame; comparing the locations of the holes against the locations measured utilizing an external measurement device; adjusting a first optical magnification or a second optical magnification at least partially based on the comparison result; defining a distortion map for each of the first and second intensity frames based on the comparison of the locations of the holes; generating an extended distortion map for each of the first and second intensity frames by map fitting the distortion map; and utilizing the extended distortion map for each of the first and second intensity frames to reduce at least one of: a registration error or an optical distortion in a subsequent measurement process.

Abstract: Methods and systems for reducing wafer shape and thickness measurement errors resulted from cavity shape changes are disclosed. Cavity calibration process is performed immediately before the wafer measurement. Calibrating the cavity characteristics every time the method is executed reduces wafer shape and thickness measurement errors resulted from cavity shape changes. Additionally or alternatively, a polynomial fitting process utilizing a polynomial of at least a second order is utilized for cavity tilt estimation. High order cavity shape information generated using high order polynomials takes into consideration cavity shape changes due to temperature variations, stress or the like, effectively increases accuracy of the wafer shape and thickness information computed.

Abstract: A calibration wafer and a method for calibrating an interferometer system are disclosed. The calibration method includes: determining locations of the holes defined in the calibration wafer based on two opposite intensity frame; comparing the locations of the holes against the locations measured utilizing an external measurement device; adjusting a first optical magnification or a second optical magnification at least partially based on the comparison result; defining a first distortion map for each of the first and second intensity frames based on the comparison of the locations of the holes; generating an extended distortion map for each of the first and second intensity frames by map fitting the first distortion map; and utilizing the extended distortion map for each of the first and second intensity frames to reduce at least one of: a registration error or an optical distortion in a subsequent measurement process.

Abstract: The present disclosure is directed to a system for measuring a thickness variation and a shape of a wafer. The system includes a first reference flat and a second reference flat. The first reference flat and the second reference flat are spaced apart to form a cavity. The cavity is configured to receive the wafer. The system also includes a plate. The plate may be inserted into the cavity with the wafer. The system also includes a first interferometer located on a first side of the cavity and a second interferometer located on a second side of the cavity. The system also includes a processor which may be in communication with the first interferometer and the second interferometer. The processor is configured to determine the thickness variation and the shape of the wafer based on at least the readings of the first interferometer and the second interferometer.

Abstract: An interferometer system is disclosed. The interferometer system includes two spaced apart reference flats having corresponding reference surfaces forming a cavity therebetween for placement of a polished opaque plate. The surfaces of the plate are approximately 2.5 millimeters or less from the corresponding reference surfaces when the plate is placed in the cavity. The interferometer system also includes two interferometer devices located on diametrically opposite sides of the cavity to map the surfaces of the plate. A light source is optically coupled to the interferometer devices. The light source includes an illuminator configured for producing light of multiple wavelengths and an optical amplitude modulator configured for stabilizing power of the light produced by the illuminator. The interferometer system further includes two interferogram detectors, and at least one computer coupled to receive the outputs of the interferogram detectors for determining thickness variations of the plate.

Abstract: The invention provides a new dual-sided Moiré wafer analysis system that integrates wafer flatness measurement capability with wafer surface defect detection capability. The invention may be, but is not necessarily, embodied in methods and systems for simultaneously applying phase shifting reflective Moiré wafer analysis to the front and back sides of a silicon wafer and comparing or combining the front and back side height maps. This allows wafer surface height for each side of the wafer, thickness variation map, surface nanotopography, shape, flatness, and edge map to be determined with a dual-sided fringe acquisition process. The invention also improves the dynamic range of wafer analysis to measure wafers with large bows and extends the measurement area closer to the wafer edge.

Abstract: Disclosed herein is a method and apparatus for reducing measurement error resulting from temperature variations across a wafer, without measuring the wafer temperature, the temperature gradient in the surrounding air, or the distribution of the index of refraction of the air.

Abstract: Interferometer systems and methods for measurement of shapes as well as their derivatives and thickness variations of wafers are disclosed. More specifically, shearing interferometry techniques are utilized in such measurement systems. The output of the measurement systems can be utilized to determine at least one of: a surface slope, a surface curvature, a surface height, a shape, and a thickness variation of the wafers.

Abstract: A semiconductor measuring tool has a folding mirror configuration that directs a light beam to pass the same space multiple times to reduce the size and footprint. Furthermore, the folding mirrors may reflect the light beam at less than forty-five degrees; thereby allowing for smaller folding mirrors as compared to the prior art.

Abstract: A method for enabling more accurate measurements of localized features on wafers is disclosed. The method includes: a) performing high order surface fitting to more effectively remove the low frequency shape components and also to reduce possible signal attenuations commonly observed from SEMI standard high pass, such as Gaussian and Double Gaussian filtering; b) constructing and applying a proper two dimensional LFM window to the residual image from the surface fitting processing stage to effectively reduce the residual artifacts at the region boundaries; c) calculating the metrics of the region using the artifact-reduced image to obtain more accurate and reliable measurements; and d) using site-based metrics obtained from front and back surface data to quantify the features of interest. Additional steps may also include: filtering data from measurements of localized features on wafers and adjusting the filtering behavior according to the statistics of extreme data samples.

Abstract: Disclosed herein is a method and system for providing environmental control for a vibration sensitive system such as an interferometric measurement system, while minimizing acoustic noise during data acquisition.

Abstract: A method and system is disclosed for utilizing two single-shot phase shift interferometers to simultaneously measure wafer shape and thickness variation of two sides of a wafer. This system is able to extract the front height, the back height, and the thickness variation of a wafer in a single data acquisition. This system, when utilized with a fast shutter speed, decreases the insensitivity to vibration. Algorithms are introduced that extract the true thickness variation of a wafer even when the wafer is vibrating. The effects of air turbulence can be reduced by a phase averaging technique.

Abstract: The invention provides a new dual-sided Moiré wafer analysis system that integrates wafer flatness measurement capability with wafer surface defect detection capability. The invention may be, but is not necessarily, embodied in methods and systems for simultaneously applying phase shifting reflective Moiré wafer analysis to the front and back sides of a silicon wafer and comparing or combining the front and back side height maps. This allows wafer surface height for each side of the wafer, thickness variation map, surface nanotopography, shape, flatness, and edge map to be determined with a dual-sided fringe acquisition process. The invention also improves the dynamic range of wafer analysis to measure wafers with large bows and extends the measurement area closer to the wafer edge.

Abstract: A method for enabling more accurate measurements of localized features on wafers is disclosed. The method includes: a) performing high order surface fitting to more effectively remove the low frequency shape components and also to reduce possible signal attenuations commonly observed from filtering; b) constructing and applying a proper two dimensional LFM window to the residual image from the surface fitting processing stage to effectively reduce the residual artifacts at the region boundaries; c) calculating the metrics of the region using the artifact-reduced image to obtain more accurate and reliable measurements; and d) using site-based metrics obtained from front and back surface data to quantify the features of interest. A method for filtering data from measurements of localized features on wafers is disclosed. This method includes an algorithm designed to adjust the filtering behavior according to the statistics of extreme data samples.

Abstract: Disclosed herein is a method and system for providing environmental control for a vibration sensitive system such as an interferometric measurement system, while minimizing acoustic noise during data acquisition.