Methods and apparatus for a chemical vapor deposition reactor

Abstract

Embodiments of the invention generally relate to a chemical vapor deposition system and related method of use. In one embodiment, the system includes a reactor lid assembly having a body, a track assembly having a body and a guide path located along the body, and a heating assembly operable to heat the substrate as the substrate moves along the guide path. The body of the lid assembly and the body of the track assembly are coupled together to form a gap that is configured to receive a substrate. In another embodiment, a method of forming layers on a substrate using the chemical vapor deposition system includes introducing the substrate into a guide path, depositing a first layer on the substrate and depositing a second layer on the substrate, while the substrate moves along the guide path; and preventing mixing of gases between the first deposition step and the second deposition step.

What is claimed is: 
     
         1 . A chemical vapor deposition system, comprising:
 an entrance isolator operable to prevent contaminants from entering the system at an entrance of the system;   an exit isolator operable to prevent contaminants from entering the system at an exit of the system;   an intermediate isolator disposed between the entrance and exit isolators;   a first deposition zone disposed adjacent the exit isolator; and   a second deposition zone disposed adjacent the exit isolator, wherein the intermediate isolator is disposed between the deposition zones and is operable to prevent mixing of gases between the first deposition zone and the second deposition zone.   
     
     
         2 . The system of  claim 1 , wherein a gas is injected into the entrance isolator at a first flow rate to prevent back diffusion of gases from the first deposition zone. 
     
     
         3 . The system of  claim 1 , wherein the gas is injected into the intermediate isolator at a first flow rate to prevent back mixing of gases between the first deposition zone and the second deposition zone. 
     
     
         4 . The system of  claim 1 , wherein a gas is injected into the exit isolator at a first flow rate to prevent contaminants from entering the system at the exit of the system. 
     
     
         5 . The system of  claim 1 , further comprising an exhaust disposed adjacent each isolator and operable to exhaust gases injected by the isolators. 
     
     
         6 . The system of  claim 1 , further comprising an exhaust disposed adjacent each deposition zone and operable to exhaust gases injected into the deposition zones. 
     
     
         7 . The system of  claim 1  further comprising:
 a housing containing the entrance, exit and intermediate isolators and the first and second deposition zones; 
 a track surrounded by the housing, wherein the track contains a guide path adapted to guide a substrate through the first and second deposition zones; and 
 a substrate carrier for moving the substrate along the guide path, wherein the track is operable to levitate the substrate carrier along the guide path. 
 
     
     
         8 . The system of  claim 7 , wherein the track comprises a plurality of openings operable to supply a gas cushion to the guide path. 
     
     
         9 . The system of  claim 8 , wherein the gas cushion is applied to a bottom surface of the substrate carrier to lift the substrate carrier from a floor of the track. 
     
     
         10 . The system of  claim 7 , wherein the track comprises a conduit disposed along the guide path and operable to substantially center the substrate carrier along the guide path of the track. 
     
     
         11 . The system of  claim 10 , wherein a gas cushion is supplied through the conduit to a bottom surface of the substrate carrier to substantially lift the substrate carrier from a floor of the track. 
     
     
         12 . The system of  claim 7 , wherein the track is tilted to allow the substrate to move from a first end of the guide path to a second end of the guide path. 
     
     
         13 . The system of  claim 7 , further comprising a heating assembly containing a plurality of heating lamps disposed along the track and operable to heat the substrate as the substrate moves along the guide path. 
     
     
         14 . A method for forming multiple epitaxial layers on a substrate using a chemical vapor deposition system, comprising:
 introducing the substrate into a channel at an entrance of the system, while preventing contaminants from entering the system at the entrance;   depositing a first epitaxial layer on the substrate, while the substrate moves along the channel of the system;   depositing a second epitaxial layer on the substrate, while the substrate moves along the channel of the system;   preventing mixing of gases between the first deposition step and the second deposition step; and   retrieving the substrate from the channel at an exit of the system, while preventing contaminants from entering the system at the exit.   
     
     
         15 . The method of  claim 14 , further comprising heating the substrate prior to depositing the first epitaxial layer. 
     
     
         16 . The method of  claim 14 , further comprising maintaining the temperature of the substrate as the first and second epitaxial layers are deposited on the substrate. 
     
     
         17 . The method of  claim 14 , further comprising cooling the substrate after depositing the second epitaxial layer. 
     
     
         18 . The method of  claim 14 , wherein the substrate substantially floats along the channel of the system. 
     
     
         19 . The method of  claim 14 , wherein the substrate is a gallium arsenide substrate. 
     
     
         20 . The method of  claim 1 , wherein one of the first and second epitaxial layers is a phosphorous gallium arsenide layer.