Apparatus for and method of real-time nanometer-scale position measurement of the sensor of a scanning tunneling microscope or other sensor scanning atomic or other undulating surfaces

摘要

A method of and apparatus for producing improved real-time continual nanometer scale positioning data of the location of sensing probe used with one of a scanning tunneling microscope, an atomic force microscope, or a capacitive or magnetic field-sensing system, for measuring the probe distance and the position relative to an atomic surface or other periodically undulating surface such as a grating or the like moving relatively with respect to the probe, and between which and the surface there exists a sensing field, through rapid oscillating of the probe under the control of sinusoidal voltages, and comparison of the phase and/or amplitude of the output sinusoidal voltages produced by current in the sensing field to provide positional signals indicative of the direction and distance off the apex of the nearest atom or undulation of the surface; and, where desired, feeding back such positional signals to control the relative movement of the probe and surface; and wherein improved operation is achieved through one or all of eliminating error caused by phase delays between the sinusoidal voltage driving the probe and its actual oscillation position, particularly when near the probe natural frequency, thereby providing for increased speed, frequency response and reliability; preventing the possible crashing of the probe into the surface and other probe-to- surface gap control problems; providing for absolute positioning; and providing for improved single and multi-probe micromachined probe design particularly of monolithic crystal wafer construction.