Semiconductor producing apparatus and producing method for epitaxial wafer using same

Abstract

By perfectly preventing a particle from being attached on a silicon wafer or a silicon epitaxial wafer before and after the silicon epitaxial growth, pit formation on the silicon epitaxial layer in RCA cleaning is prevented from occurring. A pretreatment chamber, a vapor phase growth chamber and an aftertreatment chamber are mutually connected by a transport path whose interior is clean while being isolated from the outside environment. In the pretreatment chamber, megasonic cleaning using O 3 added water is conducted (step S 2 ); in the vapor growth chamber, removal of a chemical silicon oxide film C by pre-bake (step S 4 ) and formation of a high quality silicon epitaxial layer E are conducted (step S 5 ); and in the aftertreatment chamber, passivation of the silicon epitaxial layer E is conducted by O 3 water cleaning or SC1 cleaning (step S 7 ). Since a wafer surface is always covered by the chemical silicon oxide film C in transportation after formation of the silicon epitaxial layer E, direct attachment of fine metal particles M which each are a cause of pit formation is prevented from occurring.

What is claimed is:  
     
         1 . A semiconductor producing apparatus comprising: 
 a pretreatment chamber for cleaning a silicon wafer using ozone added water;    a vapor phase growth chamber for growing a silicon epitaxial layer on the silicon wafer; and    an aftertreatment chamber for forming a chemical silicon oxide film on a surface of the silicon epitaxial layer, wherein the chambers are mutually connected by at least one transport path, whose interior is controlled to have an atmosphere isolated from the outside environment.    
     
     
         2 . A semiconductor producing apparatus according to    claim 1   , wherein the pretreatment chamber is provided with means for applying supersonic vibration to the ozone added water.  
     
     
         3 . A semiconductor producing apparatus according to    claim 1   , wherein the aftertreatment chamber is provided with solution supply means for supplying a solution including an oxidizing agent on a surface of the silicon epitaxial wafer.  
     
     
         4 . A semiconductor producing apparatus according to    claim 1   , wherein the atmosphere in the transport path is kept at a cleanliness level of class 10 or higher.  
     
     
         5 . A producing method for an epitaxial wafer comprising the steps of: 
 cleaning a surface of a silicon wafer with ozone added water in a pretreatment chamber;    transporting the silicon wafer to a vapor phase growth chamber through a transport path whose interior is controlled to have an atmosphere isolated from the outside environment;    growing a silicon epitaxial layer on the silicon wafer in the vapor phase growth chamber to obtain an epitaxial wafer;    transporting the epitaxial wafer to an aftertreatment chamber through a transport path whose interior is controlled to have an atmosphere isolated from the outside environment; and    forming a chemical silicon oxide film ona surface of the silicon epitaxial layer in the aftertreatment chamber.    
     
     
         6 . A producing method for an epitaxial wafer according to    claim 5   , wherein in the first step of cleaning the surface of a silicon wafer, the silicon wafer is cleaned with the ozone added water while applying supersonic vibration.  
     
     
         7 . A producing method for an epitaxial wafer according to    claim 5   , wherein in the fifth step of forming the chemical silicon oxide film, the chemical silicon oxide film is formed by putting the silicon epitaxial layer into contact with a solution including an oxidizing agent.  
     
     
         8 . A producing method for an epitaxial wafer according to    claim 7   , wherein ozone added water or an ammonia-hydrogen peroxide mixed solution is used as the solution.  
     
     
         9 . A producing method for an epitaxial wafer according to    claim 5   , wherein the atmosphere in a transport path is kept at a cleanliness level of class 10 or higher.