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 wall deposition. In addition, 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 chemical vapor deposition reactor for simultaneously depositing from a precursor gas thin films on a multiplicity of wafers comprising:
a first lamp module, comprising
a first multiplicity of lamps, and
a first reflector assembly; and
a wafer sleeve configured for enclosing said multiplicity of wafers, comprising a pair of wafer carrier plates to which the multiplicity of wafers are attachable to interior surfaces of both of said first pair of wafer carrier plates by mounting structures, and
two end caps, said pair of wafer carrier plates being detachably attached to said two end caps, said two end caps determining the spacing between inner surfaces of said pair of wafer carrier plates, said pair of wafer carrier plates being parallel and said inner surfaces being opposed, and wherein said two end caps and said pair of wafer carrier plates form a processing cavity, said processing cavity being closed on first opposing ends by said end caps and open on second opposing ends; and
a first illumination window;
a reactor frame for supporting said first lamp module, wherein said first illumination window is fixed between said first lamp module and said reactor frame;
a first inlet for process gas into said wafer sleeve disposed on a first side of said reactor frame; and
a first outlet for exhausting gas disposed on a second side of said reactor frame wherein said second side of said reactor frame is on an opposite side of said wafer sleeve from said first side of said reactor frame;
wherein said wafer sleeve is transportable into the reactor and exposable to said first lamp module within the reactor and, after completion of said deposition of a thin film on the multiplicity of wafers, is removable from the reactor with the wafers, and wherein each one of the pair of wafer carrier plates is configured for the attachment of at least two of said multiplicity of wafers along a direction of as flow from said first gas inlet to said first gas outlet.
2. The reactor of claim 1 , further comprising:
a second lamp module, comprising
a second multiplicity of lamps, and
a second reflector assembly; and
a second illumination window;
wherein said second illumination window is fixed between said second lamp module and said reactor frame on an opposite side from said first lamp module.
3. The reactor of claim 2 , wherein the lamps linearly extend in a first direction in parallel to the wafer carrier plates.
4. The reactor of claim 3 , further comprising a source of cooling gas for flowing a cooling gas in the first direction along each of the lamps in said lamp modules.
5. The reactor of claim 4 , wherein the source of cooling gas is directed to axially middle portions of the lamps and further comprising two exhaust ports disposed respectively near opposite ends of the lamps.
6. The reactor of claim 3 , wherein the lamps are capable of being differentially powered to provide different levels of radiation.
7. The reactor of claim 1 , further comprising a source of cooling liquid coupled to said reactor frame.
8. The reactor of claim 1 , further comprising:
a second inlet for process gas into said wafer sleeve disposed on said second side of said reactor frame; and
a second outlet for exhausting gas from said first side of said reactor frame, thereby allowing alternating directions of flow of the process gas through the sleeve.
9. The reactor of claim 1 , further comprising at least one inlet for introducing purge gas disposed on said first side of said reactor frame generally into a space within the reactor frame exterior to the wafer sleeve.
10. The reactor system of claim 1 , wherein said mounting structures are screws.
11. A reactor system for simultaneously depositing thin films on a multiplicity of wafers, comprising:
a wafer sleeve configured for enclosing said multiplicity of wafers, comprising a pair of wafer carrier plates to which the multiplicity of wafers are attachable to interior surfaces of both of said pair of wafer carrier plates by mounting structures, and
two end caps, said pair of wafer carrier plates being detachably attached to said two end caps, said two end caps determining the spacing between inner surfaces of said pair of wafer carrier plates, said pair of wafer carrier plates being parallel and said inner surfaces being opposed, and wherein said two end caps and said pair of wafer carrier plates form a processing cavity, said processing cavity being closed on first opposing ends by said end caps and open on second opposing ends; and
a reactor chamber for removably accommodating the wafer sleeve,
planar heat sources associated with first and second walls of the chamber on either side of the accommodated wafer sleeve,
a first process gas inlet positioned on a third wall of the chamber and directed to the first open end of the wafer sleeve; and
a first exhaust port positioned on a fourth wall of the chamber opposite the first wall;
wherein each one of the pair of wafer carrier plates is configured for the attachment of at least two of said multiplicity of wafers along a direction of gas flow from said first process gas inlet to said first exhaust port.
12. The reactor system of claim 11 , further comprising:
a second process gas inlet positioned on the fourth wall of the chamber and directed to the second open end; and
a second exhaust port positioned on the third wall of the chamber.
13. The reactor system of claim 11 , wherein the heat sources comprise respective lamp arrays of incandescent lamps linearly extending between the third and fourth walls respectively along the first and second walls of the chamber and further comprising:
two illumination windows respectively positioned between the lamp arrays and the accommodated wafer sleeve; and
a source of a purge gas to a region of reactor chamber between the illumination windows and the accommodated wafer sleeve.
14. The reactor system of claim 11 , wherein said mounting structures are screws.
15. A reactor system for simultaneously depositing thin films on a multiplicity of wafers, comprising:
a wafer sleeve configured for enclosing said multiplicity of wafers, comprising a pair of wafer carrier plates to which the multiplicity of wafers are attachable to interior surfaces of both of said pair of wafer carrier plates by mounting structures, and
two end caps, said pair of wafer carrier plates being detachably attached to said two end caps, said two end caps determining the spacing between inner surfaces of said pair of wafer carrier plates, said pair of wafer carrier plates being parallel and said inner surfaces being opposed, and wherein said two end caps and said pair of wafer carrier plates form a processing cavity, said processing cavity being closed on first opposing ends by said end caps and open on second opposing ends; and
a reactor chamber for removably accommodating the wafer sleeve,
planar heat sources associated with first and second walls of the chamber on either side of the accommodated wafer sleeve,
a first process gas inlet positioned on a third wall of the chamber and directed to the first open end of the wafer sleeve;
a first exhaust port positioned on a fourth wall of the chamber opposite the first wall;
a preheating module, configured to heat the wafer sleeve up to a proper temperature for processing in the first reactor chamber; and
a cool down module, configured to reduce a temperature of the wafer sleeve after processing in the first reactor chamber;
wherein the wafer sleeve is linearly transportable between the preheating module, the first reactor chamber and the cool down module, and wherein
said preheating module, said cool down module and said reactor chamber are physically separate.
16. The reactor system of claim 15 , further comprising a slit valve between said preheat module and said reactor chamber.
17. The reactor system of claim 15 , further comprising a slit valve between said reactor chamber and said cool down module.