Semiconductor device including a deep contact and a method of manufacturing such a device

Abstract

A semiconductor device includes a buried layer and a deep contact for providing a low resistive connection to the buried layer. The deep contact is formed by doped polycrystalline silicon. A method of manufacturing a semiconductor device and a deep contact for providing a low resistive connection to the buried layer, with the steps of forming a buried layer, providing an active region adjacent the buried layer and forming a deep contact for providing a low resistive connection to the buried layer by patterning a contact shape for the deep contact on an upper surface of the active region, removing part of the active region underneath the contact shape to create a deep contact cavity. Subsequently a polycrystalline silicon layer for filling the deep contact cavity is deposited and doped.

1 . A method of manufacturing a semiconductor device comprising the steps of:
 forming a buried layer on a semiconductor substrate;   providing an active region adjacent the buried layer;   forming a deep contact for providing a low resistive connection to the buried layer, wherein the deep contact comprises polycrystalline silicon that is doped and wherein the deep contact extends through the buried layer to a bottom surface of the buried layer.   
     
     
         2 . The method of  claim 1 , wherein the polycrystalline silicon is insitu doped. 
     
     
         3 . The method of  claim 1 , wherein the polycrystalline silicon is doped by first implanting dopant sources and then thermally distributing the dopant.