Title :
Temperature distribution in semiconductor wafers heated in a vertical diffusion furnace
Author :
Hirasawa, S. ; Kieda, S. ; Watanabe, T. ; Torii, T. ; Takagaki, T. ; Uchino, T.
Author_Institution :
Hitachi Ltd., Ibaraki, Japan
Abstract :
The transient temperature distribution in a row of wafers heating in a vertical diffusion furnace was calculated as the heating power of the furnace was PID (proportional plus integral plus derivative) controlled. Radiative heat transfer was combined with axisymmetric unsteady conduction in wafers and the furnace. With feedforward control of the heating power (which means that when wafers are inserted into the furnace, the heater temperature is set higher than the desired heating temperature), the temperature of the wafers reached the heating temperature rapidly. The radiative properties of silicon wafers changed from semitransparent to opaque at 500°C, and the effect of this change on the temperature distribution in the wafers was calculated. Thermoplastic deformation of the wafers is more likely to occur during withdrawal than during insertion
Keywords :
electric furnaces; heat transfer; semiconductor process modelling; temperature distribution; thermal analysis; 500 degC; PID control; Si wafers; analytical model; axisymmetric unsteady conduction; feedforward control; heating power control; radiative heat transfer; semiconductor wafers; thermoplastic deformation; transient temperature distribution; vertical diffusion furnace; Cogeneration; Furnaces; Heat transfer; PD control; Pi control; Proportional control; Silicon; Temperature control; Temperature distribution; Three-term control;
Conference_Titel :
Thermal Phenomena in Electronic Systems, 1992. I-THERM III, InterSociety Conference on
Conference_Location :
Austin, TX
Print_ISBN :
0-7803-0503-5
DOI :
10.1109/ITHERM.1992.187775