Patent ID: 6737980
Filing Date: 2004-05-18
Classification: H01L

Abstract:
A wafer lift speed monitoring apparatus of semiconductor fabricating equipment, comprising:a lift interface circuit that transmits a motor driving signal; a signal interface that receives the motor driving signal output from a command output terminal of the lift interface circuit and outputs a shaped waveform signal responsive thereto; a high frequency oscillator that generates a high frequency signal; a division circuit that divides the high frequency signal into a divided frequency signal; a cycle sampling unit that samples the shaped waveform signal by a cycle unit of the divided frequency signal to estimate a time value of the shaped waveform signal; a memory that stores a reference lift speed time value; a display unit; and a controller that controls display of a lift up/down speed time value by the display unit based on the time value output from the cycle sampling unit and outputs a warning signal if the lift up/down speed time value as compared with the reference lift speed time value stored in the memory are confirmed not to correspond.