Claims
- 1. An instrument for sensing a sample, comprising:
a sensor for sensing a parameter of the sample; a coarse stage causing relative motion between the sensor and the sample; a fine stage causing relative motion between the sensor and the sample; and at least one controller controlling the two stages so that either one or both of the two stages cause relative motion between the sensor and the sample when the sensor is sensing said parameter of the sample.
- 2. The instrument of claim 1, said fine stage having a resolution of one nanometer or better.
- 3. The instrument of claim 1, said coarse stage having a resolution of one micrometer or better.
- 4. The instrument of claim 1, wherein the two stages are such that the instrument has a range of at least 500 micrometers in at least one direction.
- 5. The instrument of claim 1, wherein said sensor is a height sensor that measures directly the height variation of a surface of the sample.
- 6. The instrument of claim 5, said sensor including:
a stylus arm having a stylus tip; and a capacitance gauge, a linear voltage differential transformer sensor or a light intensity proximity sensor.
- 7. The instrument of claim 1, wherein said sensor senses thermal variatons, or an electrostatic, a magnetic, a light reflectivity or a light transimission parameter of the sample, or the height variation of a surface of the sample.
- 8. The instrument of claim 1, wherein said sensor senses substantially simultaneously the height at one or more locations of a surface of the sample and at least another parameter of the sample at said one or more locations.
- 9. The instrument of claim 8, said sensor including a stylus tip that senses the height at one or more locations of a surface of the sample and a sensor element in the stylus tip or in the proximity of the stylus tip for sensing said at least another parameter.
- 10. The instrument of claim 1, wherein each of the two stages causes relative motion between the sensor and the sample in XYZ three dimensional space, the coarse stage comprising an XY portion for causing relative motion between the sensor and the sample in a direction substantially parallel to a surface of the sample and a Z portion for causing relative motion between the sensor and the sample in a direction substantially normal to the surface of the sample.
- 11. The instrument of claim 10, wherein the sensor is connected to the fine stage, and the fine stage is connected to the Z portion of the coarse stage, and wherein the XY portion of the coarse stage is adapted for moving the sample.
- 12. The instrument of claim 11, wherein the fine stage comprises at least one piezoelectric tube, and wherein the sensor is connected to the at least one piezoelectric tube.
- 13. The instrument of claim 11, wherein the fine stage comprises two piezoelectric tubes, said instrument further comprising a flexure hinge connecting the tubes to the sensor.
- 14. The instrument of claim 10, wherein the sensor is connected to the Z portion of the coarse stage, and the fine stage is connected to the XY portion of the coarse stage, said fine stage being adapted for supporting and moving the sample.
- 15. The instrument of claim 14, wherein the fine stage comprises three piezoelectric tubes.
- 16. The instrument of claim 14, wherein the Z and XY portions of the coarse stage are supported by and move the sensor and/or the sample relative to a fixed reference base.
- 17. The instrument of claim 10, wherein the fine stage comprises three piezoelectric tubes.
- 18. The instrument of claim 10, wherein the fine stage comprises piezoelectric stacks.
- 19. The instrument of claim 18, said fine stage further comprising a support frame, a moving frame and flexure hinges connecting the two frames, said piezoelectric stacks causing relative motion between the two frames.
- 20. The instrument of claim 1, wherein said sensor comprises a stylus arm having a stylus tip for sensing a surface parameter of the sample, and a thermocouple embedded in the stylus tip for sensing thermal variations.
- 21. The instrument of claim 1, wherein said sensor comprises:
an electrically conductive core; a conductive shield surrounding the core for sensing electrostatic charge variations; and an insulating layer separating the shield from the core.
- 22. The instrument of claim 21, wherein the sensor has a sharp tip for sensing a surface parameter of the sample, said tip being part of the insulating layer or shield.
- 23. The instrument of claim 1, wherein said sensor comprises a stylus arm having a stylus tip for sensing a surface parameter of the sample.
- 24. The instrument of claim 23, said sensor further comprising a flexure hinge connected to the arm, a force coil and means for passing current into the coil and a magnet, the force coil or the, magnet being connected to the arm, wherein electromagnetic interactions between the current in the coil and the magnet move the arm towards or away from the sample.
- 25. The instrument of claim 24, further comprising a first member supporting the flexure hinge, and a second member connected to the arm for supporting the force coil, wherein the two members, the flexure hinge, and the arm are formed from a single sheet of material to form a planar body.
- 26. The instrument of claim 25, said force coil comprising a layer of electrically conductive material on the planar body, said magnet being attached to the first member.
- 27. The instrument of claim 25, said tip being integral with or attached to said planar body at an end of the arm, said tip being substantially perpendicular to a plane of the planar body.
- 28. The instrument of claim 24, further comprising a capacitance gauge, a linear voltage differential transformer sensor or a light intensity proximity sensor for measuring motion of the arm.
- 29. The instrument of claim 1, wherein said at least one controller controls the two stages so that both of the two stages substantially simultaneously cause relative motion between the sensor and the sample when the sensor is sensing said parameter of the sample.
- 30. The instrument of claim 1, wherein said sensor comprise:
a stylus arm having a stylus tip for sensing a surface parameter of the sample; a hinge supporting the stylus so that the stylus arm is rotatable about the hinge; and means for applying a force to the stylus arm.
- 31. The instrument of claim 30, said force applying means comprising a force coil and means for passing current into the coil and a magnet, the force coil or the magnet being connected to the arm, wherein electromagnetic interactions between the current in the coil and the magnet cause the stylus arm to rotate about the hinge towards or away from the sample.
- 32. The instrument of claim 30, said force applying means comprising a capacitance means and means for applying a voltage to the capacitance means.
- 33. The instrument of claim 30, said stylus arm having a dynamic range of at least about 500 micrometers when rotated about the hinge.
- 34. The instrument of claim 30, said sensor further comprising:
stylus displacement measuring means providing a position signal to indicate the position of the stylus tip; and feedback means controlling the force applied by the force applying means in response to the position signal to cause the stylus tip apply a desired force on the sample.
- 35. The instrument of claim 34, said feedback means being such that it controls the the force applied by the force applying means in response to the position signal to cause the stylus tip apply a constant desired force on the sample.
- 36. A method for sensing a sample employing a sensor for sensing the sample, comprising the steps of:
causing relative motion between the sensor and the sample by means of a coarse stage; causing relative motion between the sensor and the sample by means of a fine stage; sensing a parameter of the sample when the sensor is moved by each of the two stages.
- 37. The method of claim 36, wherein said sensing step senses the parameter at a sensing rate that is independent of the speed of motion of the sensor by the two stages.
- 38. The method of claim 36, wherein the two stages cause relative motion between the sensor and the sample in steps at one or more frequencies, and wherein the sensing rate is independent of the one or more frequencies.
- 39. The method of claim 38, wherein the sensing rate is asynchronous with respect to the one or more frequencies.
- 40. The method of claim 36, wherein the two stages cause relative motion between the sensor and the sample sequentially.
- 41. The method of claim 36, wherein the two stages cause relative motion between the sensor and the sample substantially simultaneously.
- 42. The method of claim 41, wherein said sensing step senses the parameter when the coarse stage causes relative motion between the sensor and the sample in a direction and the fine stage does not cause relative motion between the sensor and the sample in said direction.
- 43. The method of claim 41, wherein said sensing step senses the parameter when the fine stage causes relative motion between the sensor and the sample in a direction and the coarse stage does not cause relative motion between the sensor and the sample in said direction.
- 44. The method of claim 41, wherein the moving steps cause relative motion between the sensor and the sample in two orthogonal directions in steps at different rates.
- 45. The method of claim 41, said moving step by means of the fine stage causes relative motion between the sensor and the sample along a zigzag path so that the sensor oscillates relative to the sample about a line and at a frequency higher than that of the moving step by means of the coarse stage.
- 46. The method of claim 45, said moving step by means of the fine stage causes the sensor to oscillate about the line at a substantially constant amplitude, so that the zigzag path covers a substantially rectangular area.
- 47. The method of claim 36, wherein one of or both the moving steps cause relative motion between the sensor and the sample until the sensor is in a predetermined position relative to a surface of the sample, wherein said predetermined position is an initial imaging position, and then the moving steps cause relative motion between the sensor and the sample in an initial direction substantially parallel to the surface of the sample to scan the surface.
- 48. The method of claim 47, wherein one of or both the moving steps cause relative motion between the sensor and the sample until the sensor is in contact with the surface of the sample, so that the predetermined position is one in contact with the surface of the sample.
- 49. The method of claim 47, wherein one of or both the moving steps cause the sensor to move in a plane containing the initial imaging position of the sensor and substantially parallel to the surface of the sample in a constant height mode.
- 50. The method of claim 47, wherein the sensing step senses a parameter of the sample, said parameter being a thermal variaton, electrostatic, magnetic, light reflectivity, or light transimission parameter or height variation of a surface of the sample.
- 51. The method of claim 47, said sensor including a stylus tip for contacting a surface of the sample, wherein said sensing step provides an output signal, said method further comprising applying a force on the stylus in response to said output signal so that the stylus tip exerts a substantially constant force on the surface of the sample in a constant force mode when the surface is scanned.
- 52. The method of claim 47, said sensor including a stylus tip, wherein one of or both the moving steps cause the stylus tip and the sample to move towards each other after the stylus tip and the sample are in conatct, said sensing step measuring changes in position of the stylus tip to measure the compliance of the surface.
- 53. The method of claim 36, wherein the sensing step senses substantially simultaneously the height at one or more locations of a surface of the sample and another parameter of the sample at said one or more locations.
- 54. An instrument for sensing a sample, comprising:
a sensor for sensing a parameter of the sample, said sensor including:
(a) a stylus arm having a stylus tip for sensing a surface parameter of the sample; (b) a hinge supporting the stylus so that the stylus arm is rotatable about the hinge; and (c) electromagnetic or capacitive means for applying a force to the stylus arm; and a fine stage causing relative motion between the sensor and the sample, said fine stage having a resolution of 1 nanometer or better.
- 55. The instrument of claim 54; further comprising a controller controlling the fine stage so that the fine stage causes relative motion between the sensor and the sample when the sensor is sensing said parameter of the sample.
- 56. The instrument of claim 54, said force applying means comprising a force coil and means for passing current into the coil and a magnet, the force coil or the magnet being connected to the arm, wherein electromagnetic interactions between the current in the coil and the magnet cause the stylus arm to rotate about the hinge towards or away from the sample.
- 57. The instrument of claim 54, said sensor further comprising:
stylus displacement measuring means providing a position signal to indicate the position of the stylus tip; and feedback means controlling the force applied by the electromagnetic or capacitive force applying means in response to the position signal to cause the stylus tip apply a desired force on the sample.
- 58. The instrument of claim 57, said feedback means being such that it controls the the force applied by the electromagnetic or capacitive force applying means in response to the position signal to cause the stylus tip apply a constant desired force on the sample.
- 59. The instrument of claim 54, said stylus arm having a dynamic range of at least about 500 micrometers when rotated about the hinge.
- 60. A method for measuring one or more features of a surface, comprising the steps of:
(a) scanning a first probe tip of a profilometer or scanning probe microscope along a first scan path over the surface and sensing a first feature to provide first data on the first feature; and (b) scanning a second probe tip of a profilometer or scanning probe microscope or the first probe tip along at least a second scan path over the surface and sensing at least one second feature to provide second data on the at least one second feature, said second path being shorter than the first scan path, wherein the resolution of the sensing during the second scanning step is higher than that during the first scanning step.
- 61. The method of claim 1, further comprising correlating the first and second data to correlate the first and the at least one second feature.
- 62. The method of claim 61, said first and second paths intersecting at a point or being in the vicinity of each other, wherein said correlating step correlates data relative to heights of the two paths.
- 63. The method of claim 61, said scanning step (b) scans two or more second paths at different locations of the surface, said correlating step correlating the data provided during at least one of the second paths relative to the data provided during the remaining second paths by reference to the first data.
- 64. The method of claim 63, said second paths intersecting at one or more points or being in the vicinity of the first path, wherein said correlating step correlates data relative to heights of the two or more second paths.
- 65. The method of claim 64, said sensing step in step (b) sensing the heights of protrusions or depths of holes of the surface, wherein said correlating step correlates the heights of protrusions or depths of holes of the surface sensed during step (b).
- 66. The method of claim 60, wherein said sensing step (a) has a resolution in a range of about 5 to 10 nm in a direction parallel to the surface and and in a range of about 1 to 5 nm in a direction normal to the surface, and said sensing step (b) has a resolution of about than about 1 nm.
- 67. The method of claim 60, wherein said first scan path has a length in a range of about 100 microns to about 50 mm, and said second scan path has one or more scan line segments less than 100 microns long.
- 68. The method of claim 60, wherein said sensing steps in (a), (b) sense a profile or other geometric parameter, or electrical, magnetic, optical, thermal, frictional, or van de Waals force parameter.
- 69. The method of claim 60, wherein said sensing steps (a), (b) sense different parameters.
- 70. The method of claim 60, wherein each of said first and second scan paths comprises two or more scan line segments substantially parallel to one another, a spiral scan line segment or serpentine scan line segments.
- 71. The method of claim 60, wherein said scanning steps being in a contact, non-contact or intermitent contact mode.
- 72. The method of claim 60, further comprising, prior to step (b):
(a1) determining a target area and searching the surface by means of the probe tip within said target area to provide an indication of a feature of interest by detecting such feature; and (a2) selecting said second scan path as a function of said indication.
- 73. The method of claim 72, said searching step comprising scanning the probe tip along a first search line segment in a scan; and a step (a3) of, when the feature of interest is not sensed in any prior scan, moving the probe tip by an offset from the immediately preceding search line segment and scanning the probe tip along a scan line segment substantially parallel to the first scan line segment; wherein step (a3) is repeated where necessary until the feature of interest is sensed.
- 74. The method of claim 73, further comprising a step (a4), performed after the feature has been detected by means of the probe tip, of scanning said tip along a second search line segment transverse to the first search line segment in a second scan to locate the feature of interest.
- 75. The method of claim 72, said scanning and sensing step (b) being peformed to scan and sense a plurality of second features along a plurality of second scan paths, wherein said steps (a1), (a2) are performed to select some but not all of the plurality of second scan paths.
- 76. The method of claim 60, said scanning and sensing step (b) being peformed to scan and sense a plurality of second features along a plurality of second scan paths prior to step (a), wherein the first scan path intersects or is in the vicinity of said plurality of second scan paths.
- 77. The method of claim 76, further comprising, prior to step (a), selecting said first scan path based on a least square fit calculation.
- 78. The method of claim 60, said scanning and sensing step (a) being peformed to scan and sense a first feature along a predetermined first path from a first point to a second point on or over the surface, wherein said scanning and sensing step (b) is peformed to scan and sense one or more second features along paths through the first and second points.
- 79. The method of claim 78, wherein said scanning and sensing step (b) is peformed to scan and sense a second feature along a path through the first point prior to step (a), and is peformed to scan and sense a second feature along a path through the second point after step (a).
- 80. The method of claim 60, wherein the steps (a), (b) scan the tip of a scanning probe microscope comprising a coarse stage and a fine stage for causing relative motion between the surface and the probe tip, said step (a) being performed by means of the coarse stage and step (b) being performed by means of the fine stage.
- 81. The method of claim 60, said scanning steps scanning two different probe tips, said two probe tips having predetermined fixed positions relative to one another.
- 82. The method of claim 81, said two probe tips being the probe tip of a profilometer and that of a scanning probe microscope, said steps (a), (b) being performed by means of a coarse stage for causing relative motion between the two sensors and the sample; and a fine stage for causing relative motion between the two sensors and the sample, wherein each of the two stages causes relative motion between the sensors and the sample in XYZ three dimensional space, said coarse stage comprising an XY portion for causing relative motion between the sample and the sensors in a direction substantially parallel to a surface of the sample and a Z portion for causing relative motion between the two sensors and the sample in a direction normal to the surface of the sample, wherein the sensors are connected to the fine stage, and the fine stage is connected to the Z portion of the coarse stage, and wherein the XY portion of the coarse stage is adapted for moving the sample, wherein step (a) is performed by means of the XY portion of the coarse stage and either one of the two sensors, and step (b) is performed by means of the fine stage and either one of the two sensors.
- 83. The method of claim 81, said two probe tips being the probe tip of a profilometer and that of a scanning probe microscope, said steps (a), (b) being performed by means of a coarse stage for causing relative motion between the two sensors and the sample; and a fine stage for causing relative motion between the two sensors and the sample, wherein each of the two stages causes relative motion between the sensors and the sample in XYZ three dimensional space, said coarse stage comprising an XY portion for causing relative motion between the sample and the sensors in a direction substantially parallel to a surface of the sample and a Z portion for causing relative motion between the two sensors and the sample in a direction normal to the surface of the sample, wherein the fine stage connects the sensor suitable for use in a scanning probe microscope to the Z portion of the coarse stage, and the sensor suitable for use in a profilometer is connected to the Z portion of the coarse stage, wherein step (a) is performed by means of the XY portion of the coarse stage and the sensor suitable for use in a profilometer, and step (b) is performed by means of the fine stage and the sensor suitable for use in a scanning probe microscope.
- 84. An apparatus for measuring a sample, comprising:
two sensors, one suitable for use in a profilometer, and the other in a scanning probe microscope; a coarse stage for causing relative motion between the two sensors and the sample; and a fine stage for causing relative motion between the two sensors and the sample.
- 85. The apparatus of claim 84, wherein each of the two stages causes relative motion between the sensors and the sample in XYZ three dimensional space, said coarse stage comprising an XY portion for causing relative motion between the sample and the sensors in a direction substantially parallel to a surface of the sample and a Z portion for causing relative motion between the two sensors and the sample in a direction normal to the surface of the sample.
- 86. The apparatus of claim 85, wherein the sensors are connected to the fine stage, and the fine stage is connected to the Z portion of the coarse stage, and wherein the XY portion of the coarse stage is adapted for moving the sample.
- 87. The apparatus of claim 85, wherein the fine stage connects the sensor suitable for use in a scanning probe microscope to the Z portion of the coarse stage, and the sensor suitable for use in a profilometer is connected to the Z portion of the coarse stage.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application of Ser. No. 08/598,848, filed Feb. 9, 1996, entitled “A Dual Stage Instrument For Scanning A Specimen,” which is in turn a continuation-in-part application of Ser. No. 08/362,818, filed Dec. 22, 1994, entitled “Constant-Force Profilometer with Stylus-Stabilizing Sensor Assembly, Dual-View Optics, and Temperature Drift Compensation,” referred to hereinafter as the “parent application.” This application is filed on the same day as the application entitled “System for Locating a Feature of a Surface,” referred to hereinafter as the “companion application.”
Continuations (3)
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Continuation in Parts (2)
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