Susceptor for vapor-phase growth apparatus

Abstract

It was an objective of the present invention to provide a susceptor which can prevent a increasing phenomenon of the dopant concentration of the epitaxial layer at the peripheral portion of the wafer. By providing a through-hole 7 passing through to a rear side at the outer peripheral side of the wafer inside the wafer pocket 6 , a down flow of a reacting source gas from the upper surface of the susceptor 5 is formed, so that the unwanted flow of the dopant species being exhausted at the rear surface onto the wafer surface can be avoided. As a result, a raise in the dopant concentration at the outer peripheral portion of the epitaxial layer 9 can be controlled.

1. A susceptor for a vapor-phase growth apparatus comprising at least one through hole passing through a rear side at an outer peripheral portion of a wafer pocket which is formed as a concave shape in order to mount said wafer. 
     
     
       2. The susceptor of  claim 1 , wherein the at least one through hole is shaped as a groove and a plurality thereof is provided on a periphery. 
     
     
       3. A method for growing an epitaxial layer having a lower dopant concentration than the dopant concentration of a wafer, the method comprising:
   positioning the wafer in relation to a susceptor, the susceptor having a through hole;        providing a reacting source gas to the wafer; and        forming a vapor flow through said through - hole to provide vapor flowing from an upper surface of the susceptor to a lower surface of the susceptor and thereby preventing flow of a dopant species from a rear side of the wafer to a surface of the wafer.      
     
     
       4. A method in accordance with  claim 3  wherein the susceptor further comprises a wafer pocket having a concave surface for mounting the wafer and wherein the through- hole passes - from the concave surface to the rear side of the susceptor.   
     
     
       5. The method according to  claim 3  further comprising providing the through- hole on an outer peripheral side of the wafer.   
     
     
       6. The method according to  claim 4  further comprising providing the through- hole on an outer peripheral side of the wafer.