ULTRAFAST HIGH VOLTAGE GALLIUM ARSENIDE DIODE CRYSTAL Russian patent published in 2023 - IPC H01L29/868 

FIELD: semiconductor devices.

SUBSTANCE: invention is related to high-voltage power diodes with a low recovery time of reverse resistance and doubled operating temperature. The crystal of an ultrafast high-voltage high-current p-i-n gallium arsenide diode contains a highly doped single-crystal substrate of the first conductivity type, an epitaxial layer of the first conductivity type is made on it, containing three successive regions, while the epitaxial layers are made on the substrate of the first conductivity type with a difference concentration of acceptor and donor impurities of at least 10¹⁸cm^-3, between the epitaxial layers of the first and second type of conductivity there is a thick, up to 100 mcm, with a minimized number of defects, transition i-region with a difference concentration of acceptor and donor impurities of less than 10¹¹cm^-3, the second region of the second type of conductivity is made with a smooth increase in the difference concentration of the donor and acceptor dopant from 10¹⁵cm^-3 to 10¹⁷cm^-3 and a thickness of up to 100 mcm, with the highly doped third epitaxial layer of the second conductivity type of containing local system cellular highly doped regions of the first conductivity type with the thickness of the region of the first conductivity type, less than the thickness of the highly doped epitaxial layer of the second type of conductivity, with the content around the active cathode zone of the crystal of the profile two-stage mesa-region with a depth from the surface of the highly doped epitaxial layer of the first profile of the mesa-bevel, less than the total thickness of the epitaxial layers of the second type of conductivity and i-layer, while the depth of etching of the second mesa-bevel reaches a highly doped substrate of the first type of conductivity, with atomic layer protection of the surface of the profile mesa-region with Al₂O₃ or AlN dielectrics.

EFFECT: invention provides a reduction in the density of dislocations in active epitaxial layers and an increase in stability during hard resonant switching of the diode, as well as an increase in the operating temperature.

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