Heating device of the light irradiation type
To devise a heating device of the light irradiation type in which costs can reduced by reducing the number of filament lamps and current source parts without adversely affecting the illuminance distribution with respect to a wafer, in a heating device of the light irradiation type that has a light source part, in which several filament lamps are located parallel to one another, in which at least one of the filament lamps has several filaments which are located along the bulb axis are supplied with power individually to produce light which is irradiated from the light source parts onto an article to be treated, the distance between at least some of the adjacent filament lamps to one another is nonuniform.
1. Heating device of the light irradiation type, comprising:
at least one light source part in which several filament lamps are located extending parallel to one another, and in which at least one of said filament lamps comprises several filaments which are located along the bulb axis of the bulb and which are supplied with power individually in order to produce light which radiates from the light source part onto an article to be treated, wherein the distance between at least some of the adjacent filament lamps is nonuniform, wherein the filament lamps are arranged in groups, the distance between the adjacent filament lamps differing from group to group, and wherein the first filament lamp group is located in a center region and the second filament lamp groups are located laterally from the first filament lamp group, wherein the distance between the adjacent filament lamps within the first filament lamp group is greater than the distance within the second filament lamp groups.
2. Heating device of the light irradiation type in accordance with claim 1 , wherein the distance between the filament lamps is defined as the distance between the longitudinal central axes of the filaments of adjacent filament lamps.
3. Heating device of the light irradiation type in accordance with claim 1 , wherein the article to be treated is a semiconductor wafer.
4. Heating device of the light irradiation type in accordance with claim 1 , wherein the article to be treated is a semiconductor wafer which is held by a guard ring.
5. Heating device of the light irradiation type in accordance with claim 1 , wherein there are two light source parts defining a space for the article to be treated between them.
6. Heating device of the light irradiation type in accordance with claim 1 , wherein the light source parts each have a reflector to reflect the light radiated from the filament lamps onto the article to be treated.
7. Heating device of the light irradiation type in accordance with claim 1 , wherein the comparison expression D/H≦1 is satisfied, D being the distance between the filament lamps which are adjacent to one another and H being the distance between the filament lamps and the article to be treated.
8. Heating device of the light irradiation type in accordance with claim 1 , comprising filament lamps in which several filaments which are located along the bulb axis of the bulb and which are supplied with power individually such that a rated wattage density of the filaments which are located opposite a peripheral region of the article to be treated is greater than the rated wattage density of the filaments which are located opposite the center region of the article to be treated.