Precise control method of temperature rising speed during rapid thermal processing with lamp heaters

In rapid thermal processing of a semiconductor wafer, keeping a given temperature rising speed of the wafer during the heating process is very important. We calculated the effect of various heating control methods on the error of the temperature rising speed of the wafer. We calculated the PID control, the control by correcting with temperature rising speed, the control with a thermal model, the control with a prepared relation, and the combined method. We found that the combined method with a thermal model and rising speed is a good method to decrease the error of the temperature rising speed. The minimum error of the temperature rising speed at 700°C is less than 0.1°C/s during the temperature rising process of 100°C/s and the monitoring time step of 0.05 s. We calculated the effects of control-delay-time and measuring error of the monitoring temperature on the error of the temperature rising speed.