Abstract: To provide a cross-flow fan that is ideal for use in an excimer laser device or fluoride laser device that is capable of high-speed rotation, that has high mechanical strength even at high-speed rotation and that does not suffer deformation, a rotating shaft is mounted passing through the center of cross-flow fan for a discharge excitation gas laser device. Use of the rotating shaft facilitates alignment of the rotating shaft and high-speed rotation is possible because the mechanical strength is raised. Furthermore, magnetic bearings can be used since misalignment does not develop. The flow velocity is not adversely affected even if a rotating shaft, as noted above, is utilized since a cross-flow fan for gas circulation in an excimer laser device is used under high-head, low-flow velocity conditions.

Abstract: A guard ring of a heating device of the light irradiation type in which temperature can be easily controlled, matching to the temperature change of the substrate is good, the temperature change of the substrate can be made uniform, and in which processing is also simple. The object is achieved by the having:a circular area which is opposite the substrate circumferential surface and which has essentially the same height as the substrate thickness;an annular main part which is connected to the outside of the circular area which is opposite the circumferential surface of the substrate, and which has essentially the same thickness as the substrate, and with a heat capacity per unit of area which is essentially equal to the heat capacity of the substrate; andan annular substrate bearing part with a surface which runs from the lower end of the area which is opposite the circumferential surface of the substrate in the direction to the middle, has a tapered shape.

Abstract: A heating device of the light irradiation type and a holding device which can be used for it, in which it is possible to easily effect control to make the temperature of the semiconductor wafer uniform without distortion of the guard ring occurring, even if the same heating device is used for heating semiconductor wafers of different sizes is achieved by the fact that a substrate which is subjected to heat treatment by light irradiation is fixed by not only by a guard ring but also by a concentrically disposed annular auxiliary ring with a heat capacity per unit of area which is equal to the heat capacity of the guard ring. Furthermore, several guard rings can be concentrically arranged with the outermost guard ring being fixed by a guard ring support frame.