High throughput multi-wafer epitaxial reactor
An epitaxial reactor enabling simultaneous deposition of thin films on a multiplicity of wafers is disclosed. During deposition, a number of wafers are contained within a wafer sleeve comprising a number of wafer carrier plates spaced closely apart to minimize the process volume. Process gases flow preferentially into the interior volume of the wafer sleeve, which is heated by one or more lamp modules. Purge gases flow outside the wafer sleeve within a reactor chamber to minimize deposition on the chamber walls. Sequencing of the illumination of the individual lamps in the lamp module may further improve the linearity of variation in deposition rates within the wafer sleeve. To improve uniformity, the direction of process gas flow may be varied in a cross-flow configuration. Combining lamp sequencing with cross-flow processing in a multiple reactor system enables high throughput deposition with good film uniformities and efficient use of process gases.
1. A method of simultaneously processing a multiplicity of wafers in a reactor, comprising:
mounting said multiplicity of wafers on interior surfaces of a wafer sleeve to provide a loaded wafer sleeve, said wafer sleeve including a pair of closely spaced parallel wafer carrier plates and an interior carrier plate parallel to and positioned between said pair of wafer carrier plates, said multiplicity of wafers being held on interior surfaces of both of said pair of wafer carrier plates and surfaces of said interior carrier plate, said interior carrier plate dividing an interior volume of said wafer sleeve into two separate parts;
transporting said loaded wafer sleeve to a processing position in said reactor;
heating said loaded wafer sleeve in said reactor; and
during said heating in said processing position, flowing a process gas through said interior volume of said loaded wafer sleeve.
2. The method of claim 1 , wherein said heating includes irradiating said loaded wafer sleeve with light from a multiplicity of linear incandescent lamps configured in a plane parallel to said wafer carrier plates.
3. The method as in claim 2 , wherein said process gas flows in a first direction through said interior volume of said loaded wafer sleeve and wherein each of said multiplicity of linear incandescent lamps is aligned perpendicular to said first direction.
4. The method of claim 3 , further comprising independently controlling the light output of each of said multiplicity of linear incandescent lamps.
5. The method of claim 1 , wherein said flowing includes:
a first flowing of said process gas along a first direction through said interior volume of said loaded wafer sleeve; and
a second flowing of said process gas along a second direction through said interior volume of said loaded wafer sleeve, said second direction being opposite to said first direction.
6. The method of claim 1 , wherein said process gas is a silicon-containing gas for depositing thin silicon films on said multiplicity of wafers.
7. The method of claim 1 , wherein said process gas is for depositing silicon carbide on said multiplicity of wafers.
8. The method of claim 1 , further comprising, after said flowing, transporting said loaded wafer sleeve out of said reactor.
9. The method of claim 8 , further comprising, after said transporting out of said reactor, removing said multiplicity of wafers from said wafer sleeve.
10. The method of claim 9 , wherein said removing comprises:
disassembling said loaded wafer sleeve to provide a disassembled loaded wafer sleeve; and
removing said multiplicity of wafers from said disassembled loaded wafer sleeve.
11. The method of claim 1 , wherein said mounting comprises:
mounting said multiplicity of wafers on interior surfaces of a disassembled wafer sleeve; and
assembling said loaded wafer sleeve.
12. The method of claim 1 , further comprising supplying a purge gas to a space within said reactor external to and adjacent to said loaded wafer sleeve, wherein a pressure of said purge gas in said space is greater than a pressure of said process gas in the interior volume of said loaded wafer sleeve.
13. The method of claim 1 , wherein said transporting into said reactor comprises:
increasing the separation in a first direction of an inlet gas plenum and an outlet gas plenum for providing a larger clearance between the gas plenums and said loaded wafer sleeve;
moving in a second direction said loaded wafer sleeve between the gas plenums with larger separation, wherein said first direction and said second direction are perpendicular; and
decreasing said separation in said first direction until both of the gas plenums are engaged with said loaded wafer sleeve;
wherein the gas plenums are used for said flowing said process gas through said interior volume of said loaded wafer sleeve.
14. The method of claim 1 , wherein said mounting comprises mounting said multiplicity of wafers at a small angle to the plane of said wafer carrier plates and wherein said multiplicity of wafers are mounted in mirror image configurations on facing interior surfaces of said wafer carrier plates.
15. The method of claim 14 , wherein the angular mounting of said multiplicity of wafers provides a smaller gap between opposed wafer surfaces on said facing interior surfaces of said wafer carrier plates at a downstream end of the wafer surfaces relative to the process gas flow direction.
16. The method of claim 14 , wherein said angle is between one and three degrees.