Patent ID: 7241633
Filing Date: 2007-07-10
Classification: H01L

Abstract:
1. A heat treatment apparatus comprising: a hot plate having a heating element and adapted to support a substrate to be heat treated on or above the hot plate; a first, non-contact thermometer adapted to measure temperature of a surface of the substrate supported by the hot plate without contacting the surface of the substrate; a controller adapted to control electric power supplied to the heating element, the controller including a first control unit and a second control unit, the first control unit being configured to control the electric power in a first control mode during a first stage in which the temperature of the substrate rises from a first temperature to a second temperature, the second control unit being configured to control the electric power in a second control mode during a second stage after the first stage, wherein the first control unit includes: a reference-power-value generator configured to generate, according to a power pattern, reference value of the electric power during the first stage, the power pattern defining change in the reference value of the electric power with time and determined prior to commencement of the first stage such that when the electric power is supplied to the heating element according to the power pattern, an actual temperature of the substrate rises to substantially trace a target temperature-rising curve that defines change in a target temperature of the substrate with time; a subtractor configured to calculate deviation of temperature of the substrate measured by the first thermometer at a first point of time during the first stage from the target temperature at the first point of time defined by the target temperature-rising curve; a compensation-value generator configured to generate at least one compensation value which is a function of the deviation, and of the temperature measured by the first thermometer at the first point of time or the target temperature at the first point of time; and a power-value corrector configured to correct the reference value by using the compensation value, thereby generating a corrected power value, which is a value of the electric power to be supplied to the heating element.