Method for producing silicon carbide wafer

The method addresses the challenge of maintaining consistent SiC wafer quality by using FT-IR to inspect and adjust the C/Si ratio and film thickness during manufacturing, ensuring high-quality SiC wafers with reduced defects.

WO2026146631A1PCT designated stage Publication Date: 2026-07-09DENSO CORP
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Patent Information

Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
DENSO CORP
Filing Date
2025-12-25
Publication Date
2026-07-09

AI Technical Summary

Technical Problem

Existing methods for manufacturing silicon carbide (SiC) wafers face challenges in maintaining consistent quality due to the conversion of basal plane dislocations (BPDs) into threading edge dislocations (TEDs) during epitaxial growth, which can degrade semiconductor characteristics, and the chamber atmosphere changes affecting the carbon-to-silicon ratio, leading to inconsistent wafer quality.

Method used

A method involving non-destructive quality verification using Fourier Transform Infrared Spectroscopy (FT-IR) to inspect the effective C/Si ratio and film thickness during manufacturing, adjusting gas flow rates to maintain the C/Si ratio between 0.53 and 0.68, and performing in-process inspections to ensure consistent quality.

Benefits of technology

Ensures consistent quality of SiC wafers by detecting and correcting deviations in the C/Si ratio and film thickness, preventing degradation of semiconductor characteristics.

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Abstract

This method for producing a silicon carbide wafer includes repeatedly performing in-process inspection including: growing an epitaxial layer (11) that includes a buffer layer (11a) and a drift layer (11b) disposed on the buffer layer (11a) and having a dopant concentration lower than that of the buffer layer (11a) on a single crystal substrate (10); performing effective C / Si ratio inspection after growing the epitaxial layer (11) for determining whether the effective Ci / S ratio actually contributing to the growth of the buffer layer (11a) is normal on the basis of the dopant concentration of the buffer layer (11a); and performing film thickness inspection for determining whether the film thickness of the buffer layer (11a) and the film thickness of the drift layer (11b) are normal. The effective C / Si inspection and the film thickness inspection are performed using Fourier transform infrared spectroscopy.
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