| 摘要 |
PROBLEM TO BE SOLVED: To make a disk carrier adaptable to the thermal expansion of a substrate as well and to stably and surely hold the substrate by providing the disk carrier with a circular aperture of the dimension to allow the holding of the substrate at ordinary temperature and forming a groove of a prescribed shape in the lower part thereof. SOLUTION: The circular aperture of the plate in the perpendicular direction of the disk carrier 100 is formed of the upper and lower circular parts and the radius in the upper circular part is made slightly larger than the substrate radius at the time of room temperature. The lower circular part draws an arc of 176 deg. and is provided with the groove 108 internally having side walls 108a, 108b of angle 100 deg. and a floor 108c of 0.25 mm in width to accept the outer edge 106a of the substrate. The distance between the center of the aperture and apex 108t of the groove 108 is specified to the substrate radius or below and the distance from the floor 108c is specified to the substrate radius or above. When the substrate fits into the groove 108 in a room temperature state, the edge of the substrate exists at a point of the prescribed distance from the groove floor 108c and when the temperature is 300 deg.C, the edge exists 0.04 mm above the same but the radius of the groove 108 is larger than the substrate radius at the room temperature and the substrate is held without curving.
|
