Patent ID: 6576516
Filing Date: 2003-06-10
Classification: H01L

Abstract:
A method of forming a power semiconductor device comprising the steps of:A. providing a substrate of a first or second conductivity type; B. forming a voltage sustaining region on said substrate by: 1. depositing an epitaxial layer on the substrate, said epitaxial layer having a first conductivity type; 2. forming at least one trench in said epitaxial layer; 3. depositing in said trench a first layer of material having a second dopant of the second conductivity type; 4. diffusing said second dopant to form a doped epitaxial region adjacent to said trench and in said epitaxial layer; 5. depositing in said trench a second layer of material having a first dopant of the first conductivity type; 6. interdiffusing the first and second dopants respectively located in the second and first layers of material to achieve electrical compensation in the first and second layers of material; C. forming over said voltage sustaining region at least one region of said second conductivity type to define a junction therebetween.