Enhanced selenium supply in copper indium gallium selenide processes

Abstract

A system for depositing selenium on a substrate comprises includes a substrate carrier including a body, means for holding the substrate, and a plurality of selenium vapor outlets formed in the body to direct a flux of selenium vapor onto the substrate. A selenium supply container provides selenium vapor to the selenium vapor outlets. At least one temperature sensor is coupled to the substrate carrier to sense temperature of the substrate. A heat source is positioned to heat the substrate. A controller is coupled to the temperature sensor and the heat source.

What is claimed is: 
     
         1 . A substrate carrier, which comprises:
 a body including a back plate and a pair of spaced apart, substantially parallel, side rails on the back plate, each side rail including an inwardly facing surface extending outwardly of the back plate; and,   a longitudinally extending engagement slot formed in the inwardly facing surface of each side rail adjacent the back plate to engage and hold the substrate in proximity to the back plate.   
     
     
         2 . The substrate carrier as claimed in  claim 1 , including:
 a longitudinally extending selenium vapor bore formed in each of the side rails; and,   a plurality of inwardly directed selenium vapor outlets formed in each side rail outwardly of the engagement slot and in communication with the selenium vapor bore and the inwardly facing surface.   
     
     
         3 . The substrate carrier as claimed in  claim 2 , wherein the selenium vapor outlets include a first outlet conduit in communication with the bore and a second outlet conduit in communication with the first outlet conduit and the inwardly facing surface. 
     
     
         4 . The substrate carrier as claimed in  claim 3 , wherein the second outlet conduit is larger than the first outlet conduit. 
     
     
         5 . The substrate carrier as claimed in  claim 4 , wherein the outlet conduits each have a circular cross section and are concentric with each other. 
     
     
         6 . The substrate carrier as claimed in  claim 2 , including:
 a longitudinally extending selenium vapor channel formed in the inwardly facing surface of each side rail outwardly of the engagement slot; and,   a plurality of inwardly directed selenium vapor outlets formed in each side rail and in communication with the selenium vapor bore and the selenium vapor channel.   
     
     
         7 . The substrate carrier as claimed in  claim 2 , wherein the selenium vapor outlets are substantially uniformly spaced apart along the inwardly facing surface of each side rail. 
     
     
         8 . The substrate carrier as claimed in  claim 1 , including a temperature sensor holder formed in the back plate. 
     
     
         9 . The substrate carrier as claimed in  claim 1 , including a plurality of temperature sensor holders formed in the back plate. 
     
     
         10 . The substrate carrier as claimed in  claim 1 , including:
 a selenium supply container formed in an end of the body adjacent the back plate and the side rails, the selenium supply container including a shelf portion extending between the side rails outwardly of the engagement slot, the shelf portion having formed therein a plurality of selenium vapor ports.   
     
     
         11 . The substrate carrier as claimed in  claim 1 , wherein the body is substantially rectangular. 
     
     
         12 . The substrate carrier as claimed in  claim 11 , wherein the rails are positioned on opposite sides of the back plate. 
     
     
         13 . The substrate carrier as claimed in  claim 1 , wherein the body comprises graphite. 
     
     
         14 . A system for depositing selenium on a substrate, which comprises:
 a substrate carrier including a body, means for holding the substrate, and a plurality of selenium vapor outlets formed in the body to direct a flux of selenium vapor onto the substrate;   a selenium supply container coupled to provide selenium vapor to the selenium vapor outlets;   at least one temperature sensor coupled to the substrate carrier to sense temperature of the substrate;   a heat source positioned to heat the substrate; and,   a controller coupled to the temperature sensor and the heat source.   
     
     
         15 . The system as claimed in  claim 14 , wherein:
 the carrier includes a back plate;   the means for holding the substrate includes a pair of spaced apart, substantially parallel, side rails on the back plate, each side rail including an inwardly facing surface extending outwardly of the back plate, a longitudinally extending engagement slot formed in the inwardly facing surface of each side rail adjacent the back plate to engage and hold the substrate in proximity to the back plate; and,   the plurality selenium vapor outlets are formed in each side rail outwardly of the engagement slot.   
     
     
         16 . The system as claimed in  claim 15 , wherein each selenium vapor outlet is in communication with a selenium vapor bore formed in the side rail and the inwardly facing surface of the side rail. 
     
     
         17 . The system as claimed in  claim 16 , wherein each selenium vapor bore is coupled to the selenium supply container by a tube. 
     
     
         18 . The system as claimed in  claim 14 , wherein the selenium supply container is integral with the body, and the selenium supply container includes a shelf positioned above the means for holding the substrate, and the shelf portion has formed therein the plurality of selenium vapor outlets. 
     
     
         19 . The system as claimed in  claim 14 , wherein the body comprises graphite. 
     
     
         20 . A process of depositing selenium on a substrate, which comprises:
 placing a substrate in a carrier, the carrier carrying at least one temperature sensor, and the carrier having a plurality of selenium vapor outlets positioned to direct selenium vapor on to the substrate;   vaporizing solid selenium to form a selenium vapor flux;   coupling the selenium vapor flux to the selenium vapor outlets; and,   monitoring temperature sensed by the at least one temperature sensor.