Patents Assigned to Digital Instruments, Inc.
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Patent number: 6032518Abstract: A scanned-stylus atomic force microscope (AFM) employing the optical lever technique, and method of operating the same. The AFM of the invention includes a light source and a scanned optical assembly which guides light emitted from the light source onto point on a cantilever during scanning thereof. A moving light beam is thus created which will automatically track the movement of the cantilever during scanning. The invention also allows the light beam to be used to measure, calibrate or correct the motion of the scanning mechanism, and further allows viewing of the sample and cantilever using an optical microscope.Type: GrantFiled: July 20, 1998Date of Patent: March 7, 2000Assignee: Digital Instruments, Inc.Inventors: Craig B. Prater, James Massie, David A. Grigg, Virgil B. Elings, Paul K. Hansma, Barney Drake
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Patent number: 5898106Abstract: A probe-based surface characterization or metrology instrument such as a scanning probe microscope (SPM) or a profilometer is controlled to account for errors in the vertical positioning of its probe and errors in detecting the vertical position of its probe while scanning over relatively large lateral distances. Accounting for these errors significantly improves the measurement of vertical dimensions. These errors are accounted for by subtracting reference scan data acquired from the scanned sample from measurement scan data. The measurement scan data is obtained from an area that includes the feature of interest as well as a portion of a reference area which is preferably located near to the feature of interest and which is preferably featureless. The reference scan data is obtained from an area that includes the reference area and that preferably excludes the features of interest.Type: GrantFiled: September 25, 1997Date of Patent: April 27, 1999Assignee: Digital Instruments, Inc.Inventors: Kenneth L. Babcock, Virgil B. Elings, John A. Gurley, Kevin Kjoller
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Patent number: 5714682Abstract: A scanned-stylus atomic force microscope (AFM) employing the optical lever technique, and method of operating the same. The AFM of the invention includes a light source and a scanned optical assembly which quides light emitted from the light source onto a point on a cantilever during scanning thereof. A moving light beam is thus created which will automatically track the movement of the cantilever during scanning. The invention also allows the light beam to be used to measure, calibrate or correct the motion of the scanning mechanism, and further allows viewing of the sample and cantilever using an optical microscope.Type: GrantFiled: July 11, 1996Date of Patent: February 3, 1998Assignees: Digital Instruments, Inc., The Regents of the University of CaliforniaInventors: Craig B. Prater, James Massie, David A. Grigg, Virgil B. Elings, Paul K. Hansma, Barney Drake
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Patent number: 5705814Abstract: A scanning probe microscope and method having automated exchange and precise alignment of probes, wherein one or more additional stored probes for installation onto a probe mount are stored in a storage cassette or a wafer, a selected probe is aligned to a detection system, and the aligned probe is then clamped against the probe mount. Clamping is performed using a clamp which is disabled when removing a replacement probe from the storage cassette, enabled when installing the probe on the probe mount and disabled when releasing the probe at a later time for subsequent probe exchange. Probe alignment is automated using signals from the probe detection system or by forming an optical image of the probe using a camera or similar technique and determining probe positioning using pattern recognition processing of the probe image to allow probe removal and exchange without operator intervention. Techniques for error checking are employed to ensure proper probe installation and operation.Type: GrantFiled: August 30, 1995Date of Patent: January 6, 1998Assignee: Digital Instruments, Inc.Inventors: James M. Young, Craig B. Prater, David A. Grigg, Charles R. Meyer, William H. Hertzog, John A. Gurley, Virgil B. Elings
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Patent number: 5673038Abstract: This invention relates to the field of process variable measuring and display devices and portable power supplies for process variable display devices. This invention can be used to measure and display any process variable, including pressure, temperature, volume, and flow rate. Specifically, this invention relates to an electronic process variable measuring device electronically coupled to a battery powered process variable display device which displays both a bar graph trend indication of the process variable and a digital display of the process variable. In a preferred embodiment, the process variable display device is totally self-contained, including the battery operated power supply.Type: GrantFiled: July 9, 1993Date of Patent: September 30, 1997Assignee: Houston Digital Instruments, Inc.Inventors: Richard Colgate McLatchy, Jon Douglas de Silva
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Patent number: 5560244Abstract: A scanned-stylus atomic force microscope (AFM) employing the optical lever technique, and method of operating the same. The AFM of the invention includes a light source and a scanned optical assembly which guides a light beam emitted from the laser source onto a point on said cantilever during scanning thereof. A moving laser beam is thus created which will automatically track the movement of the cantilever during scanning. The invention also allows the laser beam to be used to measure, calibrate or correct the motion of the scanning mechanism, and further allows viewing of the sample and cantilever using an optical microscope.Type: GrantFiled: April 4, 1995Date of Patent: October 1, 1996Assignees: Digital Instruments, Inc., The Regents of the University of CaliforniaInventors: Craig B. Prater, James Massie, David A. Grigg, Virgil B. Elings, Paul K. Hansma, Barney Drake
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Patent number: 5557156Abstract: A method of controlling a scanner, particularly a scanner for use in scanning probe microscopes such as an atomic force microscope, including the steps of generating a scan voltage which varies as a parametric function of time, applying the scan voltage to the scanner, sensing plural positions of the scanner upon application of the scan voltage, fitting a parametric function to the sensed scanner positions, and controlling at least one parameter of the scan voltage function based on the parametric function fitted to the sensed scanner positions in the fitting step. In a preferred embodiment, the scan voltage is a polynomial parametric function of time and the order of terms of the polynomial is set in relation to the size of the scan being controlled, with small scans having at least one order term and relatively larger scans having plural order terms.Type: GrantFiled: December 2, 1994Date of Patent: September 17, 1996Assignee: Digital Instruments, Inc.Inventor: Virgil Elings
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Patent number: 5553487Abstract: A method of operating an atomic force microscope having a probe tip attached to a free end of a lever which is fixed at its other, wherein the probe tip is scanned in forward and reverse directions in a common scanline across the surface of a sample and either the deflection of the lever or the height of the sample is detected during the forward and reverse scans. The difference between the deflection of the lever or the sample height in the forward and reverse scans is determined as a relative measure of friction. A signal relating to the normal force applied to the sample, can be determined and based thereon, a coefficient of friction of the sample is determined. The signal relating to normal force is derived either from a force curve, or by scanning the probe at different force setpoints. To enhance accuracy of topographical data, the scanning angle is varied in order to minimize differences between the probe deflection (or sample height) during scanning in the forward and reverse directions.Type: GrantFiled: July 14, 1995Date of Patent: September 10, 1996Assignee: Digital Instruments, Inc.Inventor: Virgil B. Elings
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Patent number: 5463897Abstract: A scanned-stylus atomic force microscope (AFM) employing the optical lever technique, and method of operating the same. The AFM of the invention includes a light source and a scanned optical assembly which guides a light beam emitted from the laser source onto a point on said cantilever during scanning thereof. A moving laser beam is thus created which will automatically track the movement of the cantilever during scanning. The invention also allows the laser beam to be used to measure, calibrate or correct the motion of the scanning mechanism, and further allows viewing of the sample and cantilever using an optical microscope.Type: GrantFiled: August 17, 1993Date of Patent: November 7, 1995Assignees: Digital Instruments, Inc., The Regents of the University of CaliforniaInventors: Craig B. Prater, James Massie, David A. Grigg, Virgil B. Elings, Paul K. Hansma, Barney Drake
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Patent number: 5418363Abstract: An apparatus and method for scanning a probe over a surface to either produce a measurement of the surface representative of a parameter other than the topography of the surface or to perform a task on the surface. The scanning operation is divided into two parts and with a first scan to obtain and store topographical information and with a second scan to measure the parameter of the surface other than topography or to perform the task while the probe height is controlled using the stored topographic information.Type: GrantFiled: February 25, 1994Date of Patent: May 23, 1995Assignee: Digital Instruments, Inc.Inventors: Virgil B. Elings, John A. Gurley
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Patent number: 5415027Abstract: A microscope of the scanning probe variety. This device circumvents one of the serious problems of prior art scanning probe microscopes, i.e. that the probe is always near or on the surface of the object being scanned, creating the danger of damaging the probe on the surface especially on large scans or at high scan speeds. The microscope of this invention jumps the probe over the surface, causing the probe to be near or on the surface during only a very limited portion of the scan and therefore able to scan quickly over rough surfaces without undue damage to the probe or surface. Both scanning tunneling microscopes and atomic force microscopes employing the invention are disclosed. The scanning tunneling microscope is shown with both digital and analog control of the movement of the probe.Type: GrantFiled: November 5, 1993Date of Patent: May 16, 1995Assignee: Digital Instruments, Inc.Inventors: Virgil B. Elings, John A. Gurley
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Patent number: 5412980Abstract: An atomic force microscope in which a probe tip is oscillated at a resonant frequency and at amplitude setpoint and scanned across the surface of a sample in contact with the sample, so that the amplitude of oscillation of the probe is changed in relation to the topography of the surface of the sample. The setpoint amplitude of oscillation of the probe is greater than 10 nm to assure that the energy in the lever arm is much higher than that lost in each cycle by striking the sample surface, thereby to avoid sticking of the probe tip to the sample surface. Data is obtained based either on a control signal produced to maintain the established setpoint or directly as a function of changes in the amplitude of oscillation of the probe.Type: GrantFiled: August 7, 1992Date of Patent: May 9, 1995Assignee: Digital Instruments, Inc.Inventors: Virgil B. Elings, John A. Gurley
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Patent number: 5400647Abstract: A method of operating an atomic force microscope having a probe tip attached to a free end of a lever which is fixed at its other, wherein the probe tip is scanned in forward and reverse directions in a common scanline across the surface of a sample and either the deflection of the lever or the height of the sample is detected during the forward and reverse scans. The difference between the deflection of the lever or the sample height in the forward and reverse scans is determined as a relative measure of friction. A signal relating to the normal force applied to the sample, can be determined and based thereon, a coefficient of friction of the simple is determined. The signal relating to normal force is derived either from a force curve, or by scanning the probe at different force setpoints. To enhance accuracy of topographical data, the scanning angle is varied in order to minimize differences between the probe deflection (or sample height) during scanning in the forward and reverse directions.Type: GrantFiled: November 12, 1992Date of Patent: March 28, 1995Assignee: Digital Instruments, Inc.Inventor: Virgil B. Elings
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Patent number: 5329808Abstract: This invention is an atomic force microscope having a digitally calculated feedback system which can perform force spectroscopy on a sample in order to map out the local stiffness of the sample in addition to providing the topography of the sample. It consists of a three-dimensional piezoelectric scanner, scanning either the sample of a force sensor. The force sensor is a contact type with a tip mounted on a cantilever and a sensor to detect the deflection of the lever at the tip. The signal from the sensor goes to an A-D convertor and is then processed by high-speed digital electronics to control the vertical motion of the sample or sensor. In operation, the digital electronics raise and lower the piezoelectric scanner during the scan to increase and decrease the force of the tip on the sample and to use the sensor signal to indicate the change in height of the tip to measure the which is the spring constant of the sample. This constant can be determined with nanometer spatial resolution.Type: GrantFiled: July 2, 1993Date of Patent: July 19, 1994Assignee: Digital Instruments, Inc.Inventors: Virgil B. Elings, John A. Gurley
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Patent number: 5308974Abstract: An apparatus and method for scanning a probe over a surface to either produce a measurement of the surface representative of a parameter other than the topography of the surface or to perform a task on the surface. The scanning operation is divided into two parts and with a first scan to obtain and store topographical information and with a second scan to measure the parameter of the surface other than topography or to perform the task while the probe height is controlled using the stored topographic information.Type: GrantFiled: November 30, 1992Date of Patent: May 3, 1994Assignee: Digital Instruments, Inc.Inventors: Virgil B. Elings, John A. Gurley
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Patent number: 5306919Abstract: A two dimensional piezoelectric positioning device of the type including a thin walled cylindrical shaped member of piezoelectric material. A plurality of substantially rectangular shaped members are positioned around one surface of the cylindrical shaped member to form opposite pairs of electrodes to control the two dimensional movement in accordance with voltages applied to the pairs of electrodes. Each rectangular shaped member is split into at least two electrode portions and with particular polarity voltages applied to the individual electrode portions to maintain a substantially constant length for the cylindrical shaped member during the two dimensional movement.Type: GrantFiled: September 21, 1992Date of Patent: April 26, 1994Assignee: Digital Instruments, Inc.Inventors: Virgil B. Elings, John A. Gurley
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Patent number: 5266801Abstract: A microscope of the scanning probe variety. This device circumvents one of the serious problems of prior art scanning probe microscopes, i.e. that the probe is always near or on the surface of the object being scanned, creating the danger of damaging the probe on the surface especially on large scans or at high scan speeds. The microscope of this invention jumps the probe over the surface, causing the probe to be near or on the surface during only a very limited portion of the scan and therefore able to scan quickly over rough surfaces without undue damage to the probe or surface. Both scanning tunneling microscopes and atomic force microscopes employing the invention are disclosed. The scanning tunneling microscope is shown with both digital and analog control of the movement of the probe.Type: GrantFiled: January 26, 1993Date of Patent: November 30, 1993Assignee: Digital Instruments, Inc.Inventors: Virgil B. Elings, John A. Gurley
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Patent number: 5253516Abstract: This invention is a dual mode atomic force microscope which has significant advantages for small samples. The major point of novelty of this device is the provision for mounting samples onto the deflection mechanism, thereby allowing the tip to be separately mounted. The invention therefore allows for increased flexibility in the design of the tip, which can improve the performance of the microscope. The main configuration and several tip designs and variations of the deflection mechanism and the sample holder are described. Also, methods for using a microscope of this type are presented. The invention primarily consists of an AFM where the sample is mounted on the cantilever arm, and the tip is mounted separately, not on the cantilever arm. The cantilever arm and sample are scanned relative to the sample either by moving the sample or by moving the tip.Type: GrantFiled: May 7, 1992Date of Patent: October 19, 1993Assignee: Digital Instruments, Inc.Inventors: Virgil B. Elings, John A. Gurley
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Patent number: 5237859Abstract: This invention is an atomic force microscope having a digitally calculated feedback system which can perform force spectroscopy on a sample in order to map out the local stiffness of the sample in addition to providing the topography of the sample. It consists of a three-dimensional piezoelectric scanner, scanning either the sample or a force sensor. The force sensor is a contact type with a tip mounted on a cantilever and a sensor to detect the deflection of the lever at the tip. The signal from the sensor goes to an A-D convertor and is then processed by high-speed digital electronics to control the vertical motion of the sample or sensor. In operation, the digital electronics raise and lower the piezoelectric scanner during the scan to increase and decrease the force of the tip on the sample and to use the sensor signal to indicate the change in height of the tip to measure the which is the spring constant of the sample. This constant can be determined with nanometer spatial resolution.Type: GrantFiled: May 30, 1991Date of Patent: August 24, 1993Assignee: Digital Instruments, Inc.Inventors: Virgil B. Elings, John A. Gurley, Peter Maivald
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Patent number: RE37203Abstract: A feedback control system for enhancing the feedback loop characteristics of a vertical axis control in a scanning tunneling microscope or the like, including a tip member for positioning relative to a surface for measuring the topography of the surface. A horizontal control coupled to the tip for providing a plurality of adjacent horizontal scans across the surface. A vertical control coupled to the tip for providing a vertical control of the tip during the plurality of adjacent horizontal scans. A local error signal produced in accordance with the vertical position of the tip relative to the surface in real time during the plurality of adjacent horizontal scans.Type: GrantFiled: March 4, 1998Date of Patent: June 5, 2001Assignee: Digital Instruments, Inc.Inventors: Virgil B. Elings, John A. Gurley