NOVELTY - The apparatus has a carrier (602) for supporting a substrate in a substrate processing tool, where the carrier includes an exhaust outlet. An exhaust assembly comprises an inlet (674) placed proximate to the carrier to receive process exhaust from the exhaust outlet of the carrier and another inlet to receive cleaning gas. The exhaust assembly comprises an outlet to remove the process exhaust and the cleaning gas. The carrier is coupled to the exhaust assembly. The carrier includes a purge gas conduit (628) that is fluidly coupled to the exhaust outlet of the carrier.    USE - Apparatus for processing a substrate in a substrate processing tool e.g. standalone substrate processing tool, cluster substrate processing tool and indexed inline substrate processing tool, of a semiconductor processing equipment for photovoltaic applications and solar cell fabrication applications.    ADVANTAGE - The substrate processing tool provides simple automation and a relatively simple reactor design with high throughput and process quality. The apparatus realizes simple manufacturability and an energy and cost efficient usage. The apparatus includes inline linear deposition in which an epitaxial layer is built up in separate chambers to prevent over growth or bridging of an epitaxial Silicon from the substrate over the carrier due to use of purge gas between modules, thus achieving etch effect during transfer stage from one module to the next. The apparatus allows an enclosure to be produced in multiple quantities for multiple applications via simple and cost effective process by assembling the enclosure. The apparatus allows graphite to be coated with silicon carbide to provide resistance to degradation and minimize substrate contamination. The apparatus faces substrate during processing to form a radiant cavity in the substrate to provide equal and symmetrical amount of heat to substrate, thus promoting process uniformity in the substrate. The cleaning gases prevent deposition of process byproducts within the exhaust, thus reducing downtime necessary for cleaning/maintenance. The apparatus allows design components that are based on flat plates to simplify manufacturing and minimize cost by using readily available materials in standard forms. The apparatus allows high reliability linear lamps to be optimized for specific application. The flow fields within the system can be optimized for a specific application to minimize waste, thus minimizing purge gas requirements and maximizing precursor utilization. The apparatus supplies process gases to an area between substrate supports to reduce exposure of the process gases to interior components of the modules, thus reducing material deposition on cold spots within the modules. The apparatus allows a barrier to isolate the module of a set of modules from an adjacent module to prevent cross contamination or mixing of environments between the modules.    DETAILED DESCRIPTION - The cleaning gas is chlorine containing gas such as hydrogen chloride and chlorine gas.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross sectional view of a substrate carrier and exhaust system for use in a substrate processing tool.    Carrier (602)    Purge gas conduit (628)    Inlet of exhaust assembly (674)    Controller (682)    Memory (686)