Patent ID: 9422637
Filing Date: 2016-08-23
CPC Classification: C30B,Y10T

Claim Text:
1. A system for controlling a diameter of a single crystal ingot, the system comprising: a diameter measuring sensor measuring a diameter of a single crystal ingot; a Low-Pass Filter (LPF) removing short period noise from measured data from the diameter measuring sensor, wherein the LPF is composed of a circuit including a resistor with a resistance value R and a capacitor with a capacitance value C, the LPF filtering an input voltage V an Automatic Diameter Control (ADC) sensor controlling the diameter of the single crystal ingot through controlling a pull speed by using data having the noise removed as current data, wherein the ADC sensor controls an average value AVE described by the formula AVE=((a multiple of an ingot rotation period+the rotation period/2)/a raw data measurement interval when controlling the pull speed).