Rotatable substrate supporting mechanism with temperature sensing device for use in chemical vapor deposition equipment

DETAILED DESCRIPTION In accordance with the present invention, a new and useful rotatable substrate supporting mechanism is disclosed for use in single substrate chemical vapor deposition equipment.
The rotatable substrate supporting mechanism includes a circular susceptor, or platform, for receiving a single circular substrate and supporting the substrate in the reactant gas flow path through the reaction chamber.
The susceptor is provided with an axially depending driveshaft which is suitably coupled to a variable speed drive means for rotation of the susceptor, and thus the substrate, about a vertical rotation axis.
By rotating the substrate about this axis, which is normal with respect to the center of the substrate, an averaging of the deposited material growth rates results thus overcoming the problem in concentration depletion of the deposition materials as the reactant gas flows past the substrate.
Rotation of the susceptor also produces an averaging of the temperature gradient which results in a significant reduction in the temperature differences both in the susceptor and in the substrate being supported thereon.
While the rotatability of the susceptor will inherently improve the temperature characteristics in comparison to a fixed non-rotatable susceptor, the substrate supporting mechanism of the present invention is preferably configured to provide a sophisticated temperature sensing system which can be used to produce accurate temperature control in the vicinity of the susceptor.
The temperature sensing system includes a first temperature sensor means which in the preferred embodiment, extends axially and upwardly through the axial driveshaft of the susceptor for sensing the temperature at the center of the susceptor.
A fixed concentric ring is located in close surrounding relationship with the rotatable susceptor and at least one, and preferably more, additional temperature sensing means are providing at circumferentially spaced increments in the fixed ring, and these additional temperature sensing means will sense the temperatures at various points about the rotatable susceptor