Abstract: When a semiconductor wafer is preheated by halogen lamps, the temperature of a peripheral portion of the semiconductor wafer is lower than that of a central portion thereof. A laser light emitting part disposed immediately under the center of the semiconductor wafer is rotated about the center line of the semiconductor wafer, while laser light is directed from the laser light emitting part toward the peripheral portion of the semiconductor wafer. Thus, the irradiation spot of the laser light exiting the laser light emitting part swirls around along the peripheral portion of the back surface of the semiconductor wafer so as to draw a circular trajectory. As a result, the entire peripheral portion of the semiconductor wafer at a relatively low temperature is uniformly heated. This achieves a uniform in-plane temperature distribution of the semiconductor wafer.

Abstract: When a semiconductor wafer is preheated by halogen lamps, the temperature of a peripheral portion of the semiconductor wafer is lower than that of a central portion thereof. A laser light emitting part disposed immediately under the center of the semiconductor wafer is rotated about the center line of the semiconductor wafer, while laser light is directed from the laser light emitting part toward the peripheral portion of the semiconductor wafer. Thus, the irradiation spot of the laser light exiting the laser light emitting part swirls around along the peripheral portion of the back surface of the semiconductor wafer so as to draw a circular trajectory. As a result, the entire peripheral portion of the semiconductor wafer at a relatively low temperature is uniformly heated. This achieves a uniform in-plane temperature distribution of the semiconductor wafer.

Abstract: A drum type image scanner includes a transparent cylinder 2, and a cylinder drive motor 16, which are concentrically and rigidly fixed with a bracket 18. The bracket 18 is fixed to a base 12 by connecting a key way 24 of the bracket 18 and another key way 42 of the base 12 with a key 46. An optical unit 10 is movable along a track rail 34 on the base 12. When the cylinder unit 4 and the optical unit 10 are attached to the base 12, the track rail 34 runs parallel to the axis of the cylinder 2 owing to the connection of the key ways 24 and 42. The structure eliminates troublesome adjustment for parallelism between the axis of the cylinder 2 and the track rail 34 and the concentricity of the cylinder 2 with the cylinder drive motor 16, thus simplifying attachment of the cylinder 2 to the drum type image scanner 1.