Patent ID: 6455391
Filing Date: 2002-09-24
Classification: H01L

Abstract:
A method of forming a structure with a buried region in a semiconductor device comprising the following steps:a. providing a monocrystalline silicon substrate with a flat major surface, b. introducing doping impurities into the substrate through a portion of the major surface of the substrate to a first depth to form a planar region with a first type of conductivity, c. subjecting the substrate to selective anisotropic etching to hollow out trenches in the substrate from the said portion of the major surface to a second depth greater than the first depth, d. oxidizing the silicon within the trenches starting a selected distance from the major surface of the substrate, until the portions of the substrate between adjacent trenches are transformed into silicon dioxide and until the trenches are filled with silicon dioxide below the level defined by the selected distance to form a silicon dioxide plaque, e. subjecting the substrate to a treatment of epitaxial growth from a vapor phase, the operative parameters selected to permit a growth of monocrystalline silicon both inside the portions of the trenches that are still open until the trenches are closed and on top of the major surface of the substrate, and to permit a redistribution of the doping impurities into the monocrystalline silicon grown to form a region with the first type of conductivity with substantially homogeneous resistivity buried in an epitaxial layer and extending on the silicon dioxide plaque.