Patent · US Active

Semi-insulating silicon carbide crystalline ingot having a resistivity larger than 10∧7 Ohm-cm and manufacturing method therefor

US11041255B2 · kind B2 · utility

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Key dates

Filing dateJun 24, 2019
Grant dateJun 22, 2021
Priority date
Expiry dateJul 26, 2039

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC30B25/205
  • WIPO fieldSurface technology, coating
  • WIPO sectorChemistry

Abstract

A silicon carbide crystal and a manufacturing method thereof are provided. The silicon carbide crystal includes an N-type seed layer, a barrier layer, and a semi-insulating ingot, which are sequentially stacked and are made of silicon carbide. The N-type seed layer has a resistivity within a range of 0.01-0.03 Ω·cm. The barrier layer includes a plurality of epitaxial layers sequentially formed on the N-type seed layer by an epitaxial process. The C/Si ratios of the epitaxial layers gradually increase in a growth direction away from the N-type seed layer. A nitrogen concentration of the silicon carbide crystal gradually decreases from the N-type seed layer toward the semi-insulating ingot by a diffusion phenomenon, so that the semi-insulating crystal has a resistivity larger than 107 Ω·cm.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.