Process chamber with resistive heating
A process chamber which may be operated as follows: mounting substrates in a substrate carrier; loading the substrate carrier into a vacuum chamber and mating the substrate carrier with an upper gas manifold and a lower gas manifold; providing and maintaining a vacuum environment within the vacuum chamber; making electrical contact to an at least one electrically-resistive heater; heating the substrates to a process temperature by flowing current through the at least one electrically-resistive heater; and while heating the substrates, flowing process gas through odd numbered channels from the upper gas manifold to the lower gas manifold, and simultaneously flowing process gas through even numbered channels from the lower gas manifold to the upper gas manifold; wherein the process gas comprises an inert gas and the substrates are being thermally annealed, or wherein the process gas is a dopant gas and the substrates are being doped.
1. A process chamber for annealing or doping substrates with or without devices fabricated thereon, comprising:
a vacuum chamber;
an upper gas manifold and a lower gas manifold within said vacuum chamber; and
a substrate carrier comprising a gas tight rectangular box open on upper and lower surfaces, said gas tight box comprising a first multiplicity of planar walls across the width of said box, said walls being equally spaced in a row facing each other and defining a row of channels within said box, said walls comprising mounting fixtures for a plurality of substrates, said walls comprising at least one electrically resistive heater element;
wherein said upper gas manifold and said lower gas manifold are configured to attach to said upper and lower surfaces of said substrate carrier, respectively, said upper gas manifold and said lower gas manifold connecting with upper and lower ends of said channels, said upper gas manifold and said lower gas manifold being configured to isolate gas flows in odd numbered channels from gas flows in even numbered channels, wherein said channels are numbered in order along said row, wherein said gas flows through said channels are from one of said upper gas manifold and said lower gas manifold to the other of said upper gas manifold and said lower gas manifold, and wherein said upper gas manifold and said lower gas manifold are configured to allow gas flows in odd numbered channels to be in opposite directions to gas flows in even numbered channels.
2. The process chamber of claim 1 , wherein said first multiplicity of planar walls are parallel.
3. The process chamber of claim 1 , wherein said odd numbered walls are at a first angle and said even numbered walls are at a second angle, said first and second angles being equal and opposite, relative to the direction of gas flow.
4. The process chamber reactor of claim 1 , wherein each of said first multiplicity of planar walls comprises a single electrically resistive heater element.
5. The process chamber of claim 1 , wherein each of said multiplicity of planar walls comprises a second multiplicity of electrically resistive heater elements, said second multiplicity of heater elements being arranged in parallel stripes roughly perpendicular to the direction of gas flow through said channels, from one of the upper or lower gas manifolds to the other.
6. The process chamber of claim 5 , wherein said second multiplicity of heater elements are electrically connected together in series.
7. The process chamber of claim 5 , wherein each of said second multiplicity of heater elements are configured to be independently controllable.
8. The process chamber of claim 1 , wherein said electrically resistive heater elements comprise silicon carbide coated graphite elements.
9. The process chamber of claim 1 , wherein said process chamber is an annealing chamber or a diffusion furnace.
10. A method of operating a chamber of claim 1 , comprising:
mounting substrates in said substrate carrier;
loading said substrate carrier into said vacuum chamber and mating said substrate carrier with said upper gas manifold and said lower gas manifold;
providing and maintaining a vacuum environment within said vacuum chamber;
making electrical contact to said at least one electrically resistive heater;
heating said substrates to a process temperature by flowing current through said at least one electrically resistive heater; and
while heating said substrates, flowing process gas through odd numbered channels from said upper gas manifold to said lower gas manifold, and simultaneously flowing process gas through even numbered channels from said lower gas manifold to said upper gas manifold.
11. The method of claim 10 , further comprising, during said flowing process gas, simultaneously switching the direction of gas flow in said even and odd channels to improve the uniformity of material being deposited on said substrates.
12. The method of claim 10 , wherein said process gas comprises an inert gas and said substrates are being thermally annealed, or wherein said process gas is a dopant gas and said substrates are being doped.
13. The method of claim 10 , wherein said process gas is preheated in runways in said substrate carrier before reaching said substrates mounted in said channels by heat exchange from exhaust gases to process gases through the walls of the runways.
14. A process chamber for annealing or doping substrates with or without devices fabricated thereon, comprising:
a vacuum chamber;
an upper gas manifold and a lower gas manifold within said vacuum chamber; and
a substrate carrier comprising:
a gas tight rectangular box open on upper and lower surfaces, said gas tight box comprising a multiplicity of planar walls across the width of said box, said walls being equally spaced in a row facing each other and defining a row of channels within said box, said walls comprising at least one electrically resistive heater element; and
substrate holders configured to fit within said channels, said substrate holders being configured to allow gas flow over both surfaces of said substrates when mounted in said substrate holder; and
wherein said upper gas manifold and said lower gas manifold are configured to attach to said upper and lower surfaces of said substrate carrier, respectively, said upper gas manifold and said lower gas manifold connecting with upper and lower ends of said channels, said upper gas manifold and said lower gas manifold being configured to isolate gas flows in odd numbered channels from gas flows in even numbered channels, wherein said channels are numbered in order along said row, wherein said gas flows through said channels are from one of said upper gas manifold and said lower gas manifold to the other of said upper gas manifold and said lower gas manifold, and wherein said upper gas manifold and said lower gas manifold are configured to allow gas flows in odd numbered channels to be in opposite directions to gas flows in even numbered channels.
15. The process chamber of claim 14 , wherein said first multiplicity of planar walls are parallel.
16. The process chamber of claim 14 , wherein each of said multiplicity of planar walls comprises a single electrically resistive heater element.
17. The process chamber of claim 14 , wherein each of said multiplicity of planar walls comprises a second multiplicity of electrically resistive heater elements, said second multiplicity of heater elements being arranged in parallel stripes roughly perpendicular to the direction of gas flow through said channels from one of the upper or lower gas manifolds to the other.
18. The process chamber of claim 17 , wherein said second multiplicity of heater elements are electrically connected together in series.
19. The process chamber of claim 17 , wherein each of said second multiplicity of heater elements are configured to be independently controllable.
20. The process chamber of claim 14 , wherein said process chamber is an annealing chamber or a diffusion furnace.