Overlay measurement target
Granted: May 27, 2008
Patent Number:
7379184
In an overlay metrology method used during semiconductor device fabrication, an overlay alignment mark facilitates alignment and/or measurement of alignment error of two layers on a semiconductor wafer structure, or different exposures on the same layer. A target is small enough to be positioned within the active area of a semiconductor device combined with appropriate measurement methods, which result in improved measurement accuracy.
Seismic sensor with thermal stabilization
Granted: May 20, 2008
Patent Number:
7376049
A seismometer comprising a pressure sealed enclosure; an electrical component; an axis mechanics assembly having moving components, the axis mechanics assembly being in electrical communication with the electrical component; and a thermally insulating assembly mechanically supporting and surrounding the axis mechanics assembly for minimizing heat flow from the pressure sealed enclosure to the axis mechanics assembly and for enabling transmission of a seismic signal to the axis mechanics…
Spectrometer measurement of diffracting structures
Granted: May 13, 2008
Patent Number:
7372565
A normal incidence reflectometer includes a rotatable analyzer/polarizer for measurement of a diffracting structure. Relative rotation of the analyzer/polarizer with respect to the diffracting structure permits analysis of the diffracted radiation at multiple polarity orientations. A spectograph detects the intensity of the spectral components at different polarity orientations. Because the normal incidence reflectometer uses normally incident radiation and an analyzer/polarizer that…
Characterizing residue on a sample
Granted: April 22, 2008
Patent Number:
7362448
A residue detection system collects at least one of the spectrum and image from a measurement region on a sample. Spectral analysis is performed on the collected spectrum to determine whether residue is present and if so the thickness of the residue. The spectral analysis uses a calibration metric that correlates a monitoring parameter to the thickness of the residue. The monitoring parameter is at least one of the reflectance value at one or more of the local minima and maxima in the…
Transferring, buffering and measuring a substrate in a metrology system
Granted: November 27, 2007
Patent Number:
7301623
A chuck that clamps a substrate to the top surface using, e.g., a vacuum, electrostatic force, or other appropriate means, includes a plurality of lift pins that can raise the substrate off the top surface of the chuck. The chuck may be used with a metrology device that measures the substrate using a first type of measurement, e.g., film thickness measurement, while the substrate is held flat, and measures the substrate using a second type of measurement, e.g., radius of curvature…
Metrology/inspection positioning system
Granted: November 13, 2007
Patent Number:
7295314
A metrology/inspection system moves the imaging and/or measuring equipment of the system relative to a wafer. Accordingly, measurement or inspection of the wafer does not require that the wafer be mounted on a precision stage. This allows the wafer to be at rest on any structure native in a processing apparatus when the system measures or inspects the wafer. Accordingly, measurement does not require removing the wafer from the processing apparatus and does not delay processing since the…
Image control in a metrology/inspection positioning system
Granted: October 30, 2007
Patent Number:
7289215
A metrology system includes a positioning system that produces linear and rotational motion between an imaging system and the wafer. The imaging system produces signals representing the image of the wafer in the field of view of the imaging system. A control system receives and processes the image signals, and generates corrected signals that compensate for rotational movement between the imaging system and the wafer. In response to the corrected signals, a monitor displays an image with…
Method and device for determining a characteristic of a semiconductor sample
Granted: September 4, 2007
Patent Number:
7265571
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…
Alignment target to be measured with multiple polarization states
Granted: June 26, 2007
Patent Number:
7236244
An alignment target includes periodic patterns on two elements. The periodic patterns are aligned when the two elements are properly aligned. By measuring the two periodic patterns at multiple polarization states and comparing the resulting intensities of the polarization states, it can be determined if the two elements are aligned. A reference measurement location may be used that includes third periodic pattern on the first element and a fourth periodic pattern on the second element,…
Alignment target with designed in offset
Granted: June 12, 2007
Patent Number:
7230705
An alignment target includes periodic patterns on two elements. The alignment target includes two locations, at least one of which has a designed in offset. In one embodiment, both measurement locations have a designed in offset of the same magnitude but opposite directions. For example, two separate overlay patterns that are mirror images of each other may be used. Alternatively, the magnitudes and/or directions may vary between the measurement locations. The radiation that interacts…
Modeling a sample with an underlying complicated structure
Granted: April 10, 2007
Patent Number:
7202958
A model of a sample with one or more films that overlie a complicated structure can be produced using a first portion that models the physical characteristics of the film(s) and a second portion that does not attempt to model the physical characteristics of the underlying structure, but instead models the affect of the underlying structure on incident light. By way of example, the second portion of the model may use a one-dimensional periodic pattern to model a complicated…
Eddy current sensor with concentric confocal distance sensor
Granted: February 6, 2007
Patent Number:
7173417
A metrology instrument includes an eddy current sensor that is mounted to and concentric with a confocal distance sensor. By measuring the precise vertical placement of the eddy current probe with respect to the surface of the sample using the confocal distance sensor, the accuracy and precision of the eddy current measurement is improved. Because the confocal distance sensor and the eddy current sensor are confocal, there is no need to move the relative lateral positions between the…
Apparatus and method for the measurement of diffracting structures
Granted: October 3, 2006
Patent Number:
7115858
A normal incidence reflectometer includes a rotatable analyzer/polarizer, which permits measurement of a diffracting structure. Relative rotation of the analyzer/polarizer with respect to the diffracting structure permits analysis of the diffracted radiation at multiple polarity orientations. A spectograph detects the intensity of the spectral components at different polarity orientations. Because the normal incidence reflectometer uses normally incident radiation and an…
Pulsed spectroscopy with spatially variable polarization modulation element
Granted: June 20, 2006
Patent Number:
7064828
A metrology device, such as an ellipsometer, includes a light source that produces a pulsed electromagnetic beam, such as a flash bulb or pulsed laser, and a spatially dependent polarizing element that introduces a spatially dependent retardation in the light beam. The use of a pulsed light source is advantageous over a continuous light source, as a pulsed light source generates less heat, is stronger, lasts longer, and does not need the use of a mechanical shutter. The use of a…
Polarizing beam splitter and dual detector calibration of metrology device having a spatial phase modulation
Granted: June 13, 2006
Patent Number:
7061613
An ellipsometer with a variable retarder, which introduces a spatial dependence in the beam, includes a polarizing beam splitter to produce two beams with orthogonal polarization states. The beam splitter may be, e.g., a polarizing displacer or polarizing beam splitter. The intensities of the two beams are measured, e.g., using separate detectors or separate detector elements in an array. The intensity from the two beams may be summed and used as a reference to normalize intensity of the…
Spectroscopically measured overlay target
Granted: June 13, 2006
Patent Number:
7061615
An overlay target for spectroscopic measurement includes at least two diffraction gratings, one grating overlying the other. The diffraction gratings may include an asymmetry relative to each other in order to improve resolution of the presence as well as the direction of any mis-registration. For example, the asymmetry between the two diffraction gratings may be a phase offset, a difference in pitch, line width, etc. The overlay target may be spectroscopically measuring, for example,…
Positioning two elements using an alignment target with a designed offset
Granted: May 16, 2006
Patent Number:
7046361
An alignment system for aligning two elements includes an alignment target with periodic patterns on each element. The alignment target includes two locations, at least one of which has a designed in offset. If desired, both locations may have designed in offsets of the same magnitude but in opposite directions. The diffraction patterns produced at the two locations are compared. If the difference between the patterns is at a minimum, the elements are properly aligned. When an alignment…
Edge grip chuck
Granted: April 25, 2006
Patent Number:
7032287
An actuated edge grip chuck includes tabs with raised portions that press against the side of a substrate as opposed clamping on the top or bottom surfaces. The edge grip chuck includes a solid-state actuator to move a moveable tab into an open position. The solid-state actuator may be, e.g., a piezoelectric actuator or a shape memory alloy. The tab may be biased into the closed position such that when a substrate is held by the edge by the moveable tab and one or more fixed tabs. If…
Method and apparatus for inspecting defects on polishing pads to be used with chemical mechanical polishing apparatus
Granted: April 11, 2006
Patent Number:
7027640
The present invention provides an apparatus and method for detecting or inspecting defects on a polishing pad for use in performing chemical mechanical polishing of a wafer. The apparatus for detecting the defects on the pad comprises a pad driving device for loading the pad thereon and moving the pad, at least one camera installed to face the pad for converting an image of the pad into an electrical signal and outputting the converted electrical signal, a digital image data acquisition…
Accurate thickness measurement of thin conductive film
Granted: February 28, 2006
Patent Number:
7005306
The thickness of a thin conductive film is accurately measured without direct knowledge of the temperature of the sample. A coulometer measurement during deposition of the conductive film on a substrate, along with other data such as the plated surface area, the electrochemical reaction, the molar volume of the deposited metal and the coulombic efficiency, is used to determine the average thickness of the film. Eddy current measurements yield the sheet resistance of the film at a…
