Sensor devices with internal packaged coolers
Granted: May 15, 1990
Patent Number:
4926227
Heat sensitive sensors, such as charge coupled devices which must be cooled to reduce dark current leakage, are packaged in a chip carrier and in contact with the cold surface of an electrothermal cooler the warm opposite surface of which contacts the floor of the carrier to heat the carrier body and the window of the chip carrier to prevent fogging of the cover glass while the sensor remains cold.
Method for normalizing the detection signals of magnified images of fluorescing materials
Granted: December 5, 1989
Patent Number:
4884890
A feedback method, or automatic gain control circuit, for an image photosensor at the focal plane of an optical system for very narrow linewidth measurements of images having varying intensities such as fluorescing photoresist coated lines. The feedback method includes the steps of measuring the instantaneous intensities of the entire optical beam of radiation with a photodetector and applying the output therefrom to the photosensor to thus normalize its output signal.
Thickness measurements of thin conductive films
Granted: July 18, 1989
Patent Number:
4849694
Either resistivity or thickness of conductive thin films may be measured if the other one of the properties is known. The system employs eddy current apparatus including an alternating frequency driving coil, a detector coil mounted in a housing adjacent one surface of the thin film, and circuitry for measuring the signal across the detector coil which senses the field after it is subjected to the eddy currents generated within the conductive film. Precise adjustment of a fixed distance…
Thin dielectric film measuring system
Granted: May 2, 1989
Patent Number:
4826321
A system for the precise measurement of thin dielectric films on a substrate by directing a plane polarized laser light beam to the film at the Brewster angle of the substrate and by measuring the intensity changes between a measurement from the substrate alone and from the film coated substrate. Accurate thin film measurements in the range of from about 10 to 1,500 Angstroms are possible.
Secondary electron emission control in electron microscopes
Granted: May 10, 1988
Patent Number:
4743757
In a scanning electron microscope, a co-planar, split grid is interposed between an electron bombarded specimen and scintillator. A first positive potential is applied to one element of the split grid and a positive potential, variable with respect to the first potential, is applied to the other grid element for selectively controlling the collection of secondary emission electrons to thereby eliminate uneven secondary electron distribution that may result from various topographical…
Method for electron gun alignment in electron microscopes
Granted: May 5, 1987
Patent Number:
4663525
In an electron microscope employing a multi-element electrostatic lens and a position adjustable electron emission gun, the gun tip must be in precise alignment with the very small apertures in the lens elements for high resolution imaging. If the tip is precisely aligned, there will be no variations in displacement of an image if the lens element potentials are varied; if there is misalignment, the image displacement will vary with voltage variations. Thus, proper alignment of the gun…
Microscope stage assembly and control system
Granted: December 2, 1986
Patent Number:
4627009
A computerized stage assembly for a Scanning Electron Microscope including a support frame, a tilt frame pivotally coupled to the support frame, an X carriage engaged with the tilt frame for movement in an X direction, a Y carriage engaged with the X carriage for movement in a Y direction, and a pedestal carried by the Y carriage and capable of rotation around an axis substantially normal to both the X and Y directions. The tilt frame, X and Y carriages, and pedestal are moved by…
Integrated circuit wafer handling system
Granted: August 5, 1986
Patent Number:
4604020
A system for transfering discs, such as integrated circuit wafers during manufacture, from a location at atmospheric pressure into a vacuum chamber of an electron microscope or the like with a minimum of vacuum loss to the chamber. A wafer is placed on a moveable holder in a small sealable chamber having a sealable top door and which is mounted to the outer surface of the vacuum chamber at the position of a small gate through the chamber wall. The wafer holder carries a magnet that is…
Method and apparatus for automatic optical focusing on an optically discernible feature on an object
Granted: July 15, 1986
Patent Number:
4600832
A method for the automatic fine focusing of an image scanning densitometer, micrometer, or television camera or the like, after an initial manual focus has been made on the edge of a discernible feature on the surface of an object of interest. A plurality of at least three, and preferably five, scans are made across the image of the feature at a corresponding plurality of focus positions, and the variations in light intensities are noted at each of a plurality of locations in each scan…
Three-stage secondary emission electron detection in electron microscopes
Granted: June 24, 1986
Patent Number:
4596929
In scanning electron microscopes the field established between the focusing lens housing at ground potential and the secondary emission electron detector at a positive potential attracts and carries the secondary electrons to the detector. This field is often displaced from the secondary emission source so that much of the emission is attracted to other areas of the microscope and is lost to the detector. To greatly improve detection efficiency, an electron attracting grid at a potential…
Linewidth measuring with linearity calibration of the T.V. camera tube
Granted: June 4, 1985
Patent Number:
4521686
In making precision measurements with a television camera tube, the inherent scan non-linearity and magnification variations are readily calibrated by painting a grid of known dimensions on the tube face.
Integrated circuit wafer transport mechanism
Granted: January 24, 1984
Patent Number:
4427332
A manually operable mechanism for attachment to the adjustable stage of an inspection microscope for lifting a selected printed circuit wafer from its slot in a conventional disc holder and positioning it under the microscope lens for inspection. After inspection the mechanism is operated to lift the wafer from its inspection position, to transport it back into the disc holder, and carefully lower it into its correct slot. There is no manual handling of the wafers and therefore the…
Computerized micromeasuring system and method therefor
Granted: February 15, 1983
Patent Number:
4373817
Very narrow lines, such as integrated circuit conductors, are accurately measured with consistent accuracy using a microscope that projects the image of the narrow object against a slit behind which is a photomultiplier tube. The photomultiplier tube and slit are moved in very small steps under the control of a microcomputer that measures the photomultiplier tube amplitude at each step, eliminates background error due to illumination irregularities, etc., and provides a printout of the…
Method for the precise determination of photoresist exposure time
Granted: December 29, 1981
Patent Number:
4308586
A method for determining the precise exposure for a photoresist coating by measuring the coating thickness with a microspectrophotometer that provides data for plotting a nearly sinusoidal curve of percent reflectivity versus wavelength. The nominal exposure derived from the thickness measurement is then corrected to a precise value by extrapolation and normalization of the curve at the photosensitive wavelength of the photoresist.
