Chemical vapor deposition reactor and method
AssigneeAG Associates
InventorsJames McDiarmid, Kristian E. Johnsgard
Life of this patent
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Abstract
A CVD reactor and method for growing semiconductor material upon a selected surface of a semiconductor wafer supported within the reactor includes a plurality of heat shields that are arranged relative to the peripheral edge and underside of the wafer to alter the radiation of flux from the wafer that is heated to elevated temperatures by a bank of high-intensity lamps that are oriented to illuminate the upper side of the wafer through a transparent wall of the reactor. A reactant gas flowing into the chamber from above the wafer is inhibited from flowing about the underside of the wafer, thereby assuring wafers that are not contaminated on the underside.
Claims22
Reactor apparatus for forming CVD depositions on a semiconductor wafer, the reactor apparatus comprising:
- a chamber including walls forming boundaries about the chamber, and including an upper wall of the chamber that is substantially transparent to radiation within a selected waveband for admitting radiant flux into the chamber through the upper wall;
- source means of radiant flux disposed adjacent the upper wall of the chamber for supplying radiant flux within a selected waveband into the chamber;
- support means disposed within the chamber for positioning a semiconductor wafer in selected position adjacent the upper wall for receiving radiant flux therethrough, said support means including an outer annulus having a recess therein for supporting a semiconductor wafer within the recess of the annulus;
- and
- a heat shield disposed in close proximity to the underside of the outer annulus and to the underside of a semiconductor wafer supported by the annulus, said heat shield being positioned in substantially plane-parallel relationship to the outer annulus and a semiconductor wafer supported thereby.
A method of forming epitaxial deposition on a semiconductor wafer in a reaction chamber having an upper wall that is substantially transparent to radiant flux within a selected waveband, the method comprising the steps of:
- supporting the wafer within the chamber adjacent the upper wall for receiving radiant flux therethrough;
- surrounding the periphery of the wafer with an upper heat shield surrounding the wafer for altering radiation of flux from the wafer;
- and
- supporting a lower heat shield within the chamber in close proximity to the underside of the wafer and the surrounding upper heat shield, said lower heat shield being positioned in substantially plane-parallel relationship to the under side of the wafer and the upper heat shield surrounding the wafer for altering radiation of flux from the wafer and upper heat shield.
Dependencies are inferred from the claim text.