Process chamber with resistive heating

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.