Semiconductor device with a semiconductor body and method for its production

Abstract

A semiconductor device with a semiconductor body and method for its production is provided. The semiconductor body includes drift zones of epitaxially grown semiconductor material of a first conduction type. The semiconductor body further includes charge compensation zones of a second conduction type complementing the first conduction type, which are arranged laterally adjacent to the drift zones. The charge compensation zones are provided with a laterally limited charge compensation zone doping, which is introduced into the epitaxially grown semiconductor material. The epitaxially grown semiconductor material includes 20 to 80 atomic % of the doping material of the drift zones and a doping material balance of 80 to 20 atomic % introduced by ion implantation and diffusion.

1 . A semiconductor device with a semiconductor body, comprising:
 drift zones of a first conduction type comprising epitaxially grown semiconductor material,   charge compensation zones of a second conduction type complementary to the first conduction type, which are arranged laterally adjacent to the drift zones and comprise a laterally limited charge compensation zone doping, which is introduced into the epitaxially grown semiconductor material;   the epitaxially grown semiconductor material comprising 20 to 80 atomic % of the doping material of the drift zones distributed in the epitaxially grown semiconductor material and a doping material balance between 80 and 20 atomic % introduced by ion implantation and diffusion.   
   
   
       2 . The semiconductor device of  claim 1 , wherein the epitaxially grown semiconductor material comprises 20 to 80 atomic % of the doping material of the drift zones homogeneously distributed in the epitaxially grown semiconductor material. 
   
   
       3 . The semiconductor device of  claim 1 , wherein the epitaxially grown semiconductor material is applied in epitaxial growth phases and 20 to 80 atomic % of the doping material of the drift zones are inhomogeneously distributed in the epitaxially grown semiconductor material such that a minimum of the concentration of doping material is located in a middle region of an individual epitaxial growth phase. 
   
   
       4 . The semiconductor device of  claim 1 , wherein the doping material balance of 80 to 20 atomic % introduced by ion implantation and diffusion has a maximum concentration of doping material at the end of an individual epitaxial growth phase. 
   
   
       5 . The semiconductor device of  claim 1 , wherein the concentration of the doping material balance introduced by ion implantation and diffusion is higher than the concentration of the doping material of the epitaxially grown semiconductor material. 
   
   
       6 . The semiconductor device of  claim 1 , wherein the concentration of the doping material balance introduced by ion implantation and diffusion comprises nearly two thirds of the total concentration of the doping material of the drift zones. 
   
   
       7 . The semiconductor device of  claim 1 , wherein the doping material balance for drift zones is introduced over a large area and unmasked into the epitaxially grown semiconductor material. 
   
   
       8 . The semiconductor device of  claim 1 , wherein the charge compensation zones comprise column- or strip-shaped regions introduced by masked ion implantation and diffusion in the epitaxially grown semiconductor material. 
   
   
       9 . The semiconductor device of  claim 1 , wherein the semiconductor device comprises a near-surface body zone with a doping complementary to the first conduction type, in which there is located a source zone of the first conduction type, which is doped more highly than the drift section and which is contacted by a metallic source electrode similar to the body zone. 
   
   
       10 . The semiconductor device of  claim 1 , wherein the laterally integrated doping material dose C D  in the drift zones or the charge compensation zones is less than twice the breakdown charge of silicon. 
   
   
       11 . The semiconductor device of  claim 1 , wherein the laterally integrated doping material dose C D  in the drift zones or the charge compensation zones is less than twice the breakdown charge C L  at a typical doping and C D ≦2 C L  of silicon with C D =3×10 12  cm 2 . 
   
   
       12 . The semiconductor device of  claim 1 , wherein the charge compensation zones are arranged at a process size p, the process size p in micrometers being p≦12 μm. 
   
   
       13 . A method for the production of a semiconductor device with a semiconductor body having drift zones of a first conduction type and charge compensation zones of a complementary conduction type, the method comprising:
 a) providing a semiconductor wafer as a semiconductor substrate;   b) applying an epitaxial layer in a first epitaxial growth phase, during which the semiconductor material is in the process of epitaxial growth doped on the semiconductor wafer with 20 to 80 atomic % of a doping material of the first conduction type;   c) unmasked ion implantation of doping material of the first conduction type for the near-surface introduction of a doping material balance of 80 to 20 atomic % into the epitaxial layer;   d) masked ion implantation for a charge compensation zone structure with a doping complementary to the drift zone;   e) repeating steps b) to d) until a predetermined epitaxial layer thickness is reached;   f) indiffusing of the doping materials for the drift zones and the charge compensation zones until coherent charge compensation zones are generated;   g) completing of a semiconductor chip structure for power semiconductor devices on the semiconductor wafer.   
   
   
       14 . The method of  claim 13 , wherein the doping with 20 to 80 atomic % of the doping material of the first conduction type is carried out with homogeneous distribution during the application of the epitaxial layer in the epitaxial growth phase. 
   
   
       15 . The method of  claim 13 , wherein the doping with 20 to 80 atomic % of the doping material of the first conduction type is carried out with inhomogeneous distribution during the application of the epitaxial layer in the epitaxially grown semiconductor material in such a way that a maximum of the concentration of doping material is introduced into the semiconductor material in a middle region of an individual epitaxial growth phase. 
   
   
       16 . The method of  claim 13 , wherein the thickness of the individual epitaxial layers per repetition step is increased compared to conventional techniques and the number of repetition steps is reduced accordingly. 
   
   
       17 . The method of  claim 13 , wherein a doping material balance for the first conduction type, the concentration of which is higher than the concentration of the already homogeneously distributed doping material of the epitaxially grown semiconductor material, is introduced by ion implantation and diffusion. 
   
   
       18 . The method of  claim 13 , wherein a doping material balance with a concentration comprising nearly two thirds of the total concentration of doping material of the drift zones is introduced near the surface by using ion implantation and diffusion. 
   
   
       19 . The method of  claim 13 , wherein a doping material balance for drift zones is introduced over a large area and unmasked into the epitaxially grown semiconductor material by ion implantation and diffusion. 
   
   
       20 . The method of  claim 13 , wherein the charge compensation zones are introduced in column- or strip-shaped regions into the epitaxially grown semiconductor material by masked ion implantation and diffusion. 
   
   
       21 . The method of  claim 13 , wherein body zones with a doping complementary to the first conduction type are introduced near the surface into the epitaxially grown semiconductor material, wherein source zones of the first conduction type with a higher doping than the drift zones are introduced into the body zones, and wherein contact holes are then produced through an insulating layer up to the source zones and the body zones, to which a conductive source electrode structure is subsequently applied. 
   
   
       22 . The method of  claim 13 , wherein the introduction of the doping materials provides a doping material dose C D  in the drift zones and into the charge compensation zones which is less than the breakdown charge C L  with C D ≦C L  of silicon with C L =2×10 12  cm −2 . 
   
   
       23 . The method of  claim 13 , wherein the charge compensation zones are arranged at a step size p in micrometers, with p≦11 μm. 
   
   
       24 . The method of  claim 13 , wherein, within the epitaxially grown semiconductor material, the homogeneously distributed concentration of the doping material of the drift zones never falls below the set value at any time during production. 
   
   
       25 . The method of  claim 13 , wherein the completion of the semiconductor chip structures for power semiconductor devices on the semiconductor wafer is followed by the thinning of the semiconductor substrate and by its cutting into semiconductor chips.