MEASUREMENT CONTROL CIRCUIT DEVICE FOR MEASURING SURFACE SHAPE OF SAMPLE BY STYLUS TYPE STEP PROFILER

摘要

PROBLEM TO BE SOLVED: To provide a compact, low-cost measurement control circuit device capable of minimizing jumping of a needle of a stylus type step profiler.;SOLUTION: The measurement control circuit device for measuring a surface shape of a sample by the stylus type step profiler provided with a probe movable not only vertically to a surface of a measurement object sample, but relatively along the surface of the measurement object sample, a needle pressure application means for exerting to the probe a needle pressure vertically applied to the surface of the measurement object sample, a differential transformer detecting a vertical displacement of the probe, and a control means for increasing/decreasing the needle pressure of the probe by detecting the jumping of the probe based on an output signal of the differential transformer and controlling the needle pressure application means according to detection of the jumping of the probe; includes a digital signal processor forming a reference signal by phase adjustment of a signal having the same frequency as a primary voltage to be applied to the primary side of the differential transformer, multiplying this reference signal by a signal detected from the secondary side of the differential transformer detecting a vertical displacement of the probe, and generating a signal indicating a vertical displacement value of the probe; and a circuit generating a control signal which controls a current value of a force generating coil of the needle pressure application means.;COPYRIGHT: (C)2011,JPO&INPIT