Abstract: A boat includes a boat body, a top plate mounted on one end and a bottom plate mounted on the other end of the boat body. The boat body has a prop section and the prop section has a plurality of support portions provided parallel to each other along its longitudinal direction and each having a substantially circular arc-like configuration. The support portion has an opening at a front side to allow the forward end of an arm to be entered into an inside of the support portion to transfer a wafer W. Another opening is provided in a back section of a prop section at an area corresponding to the opening to allow the forward end of the arm to extend through it. The support portion supports the wafer W with the wafer edge portion set on its rest surface. The support portion and its rest surface are so formed as to have a substantially circular arc-configuration. By doing so, the rest surface of the support portion supports the wafer edge portion over as greater a length as possible.

Abstract: A heat treatment apparatus comprising a holder, a hollow cylindrical cover, a flat plate, and a processing chamber. The holder holds disk-shaped objects, each having an orientation flat portion at circumference. The objects are arranged coaxially and spaced at predetermined intervals, with the orientation flat portions aligned with one another. The cover has gas ports and surrounds the objects held by the holder and is spaced from a circumference of each object by a predetermined distance. The flat plate is mounted on an inner surface of the cover and opposes the orientation flat portions of the objects. In the processing chamber, the objects held by the holder are processed by using a process gas.

Abstract: A heat treatment boat for mounting a number of disc-shaped objects to be treated at a vertical interval for heat treatment thereof in a vertical heat treatment furnace comprises arcuate or ring-shaped support members provided on support rods at a vertical interval for supporting the objects to be treated in surface contact with the undersides of peripheral parts of the objects to be treated. The heat treatment boat is disposed on a ring-shaped intermediate member of high radiant heat absorption disposed on a heat insulating cylinder. The heat treatment boat comprises support rods which are planted on an annular support member circumferentially in accordance with a contour of the objects to be treated and whose upper ends are secured to an annular fixation member. The heat treatment boat of such constitution can reduce occurrences of slips in the disc-shaped objects when heat treated.