Semiconductor component and method for producing it

Abstract

A semiconductor component having differently structured cell regions, and a method for producing it. For this purpose, the semiconductor component includes a semiconductor body. A first electrode on the top side of the semiconductor body is electrically connected to a first zone near the surface of the semiconductor body. A second electrode is electrically connected to a second zone of the semiconductor body. Furthermore, the semiconductor body has a drift path region, which is arranged in the semiconductor body between the first electrode and the second electrode. A cell region of the semiconductor component is subdivided into a main cell region and an auxiliary cell region, wherein the breakdown voltage of the auxiliary cells is greater than the breakdown voltage of the main cells.

What is claimed is: 
     
         1 . A method for producing semiconductor components having a drift path and main cell region and auxiliary cell region, wherein the properties of the drift path with regard to the breakdown voltage in the main cell region differ from the properties of the drift path in the auxiliary cell region, the method comprising:
 patterning a semiconductor wafer composed of a monocrystalline semiconductor body with semiconductor component structures in semiconductor chip positions which have diode, MOSFET or IGBT structures with a lateral or vertical drift path for the main cell region and the auxiliary cell region;   introducing vertical trench structures into the drift path in the auxiliary cell region;   depositing an insulating layer on the trench walls of the trench structures; and   filling the trench structures with a conductive material to form field plates.   
     
     
         2 . The method of  claim 1 , wherein longer trench structures for field plates in the case of a lateral drift path are introduced in the auxiliary cell region than in the main cell region. 
     
     
         3 . The method of  claim 1 , wherein the drift path is doped more highly in the auxiliary cell region than in the main cell region. 
     
     
         4 . The method of  claim 1 , wherein the trenches for the field plates are introduced with smaller spacings in the main cell region than in the auxiliary cell region. 
     
     
         5 . The method of  claim 1 , wherein an oxide thickness profile that differs from the oxide thickness profile of the trench structure of the field plates in the main cell region is provided for the field plates in the auxiliary cell region. 
     
     
         6 . The method of  claim 1 , wherein deeper trench structures for field plates in the case of a vertical drift path are introduced in the auxiliary cell region than in the main cell region. 
     
     
         7 . The method of  claim 1 , wherein, in the auxiliary cell region, at least one of a p−-conducting discharge layer is implanted or diffused as a field plate discharge structure before the trench structure is introduced and a pt conducting strip arranged transversely with respect to the drift path is implanted or diffused as field plate discharge structure before the trench structure is introduced. 
     
     
         8 . The method of  claim 1 , wherein, before dopants are introduced, first a patterned masking layer is applied to the semiconductor wafer, which layer covers the surface regions of the semiconductor body that are not doped. 
     
     
         9 . The method of  claim 1 , wherein, for introducing dopants, a dopant-containing layer is deposited on the masking layer patterned with windows and an indiffusion of the dopants into the semiconductor wafer is subsequently carried out. 
     
     
         10 . The method of  claim 1 , wherein, before vertical trench structures are introduced into the drift path, a patterned masking layer is applied to the semiconductor wafer, which layer has windows in the regions of the field plates.