Apparatus for uniformly heating a substrate

Claim 1

Apparatus for uniformly heating a relatively large area, relatively thin substrate within a low pressure, elevated temperature deposition chamber wherein a semiconductor layer is deposited onto said substrate: said apparatus including, in combination: a glow discharge deposition chamber; means for moving said substrate through said chamber; a plurality of spaced, generally linear, elongated, radiant heating elements spaced from and angled relative to the plane of the substrate within the deposition chamber; and, means associated with each of said heating elements for adjusting (1) the distance between a first end of each heating element and the substrate relative to the distance between a second end of said element and the substrate, and (2) the proximity, in the transverse direction relative to the plane of the substrate, of the adjacent one of the ends of theheating elements from the edge portions of the substrate, so as to direct the greatest intensity of radiation onto the edges portions of the substrate, since said edge portions of the substrate lose heat at the greatest rate; and housing means for holding each heating element in an angled condition relative to the substrate so that each heating element is disposed at a minimum distance from the substrate adjacent the edge portions of the substrate and at maximum distance from the substrate adjacent the center of the substrate, whereby, a substantially uniform temperature distribution across the transverse width of the substrate is established.