Ultrahigh-quality silicon carbide single crystals.

Area of Science:

• Materials Science
• Solid State Physics
• Semiconductor Technology

Background:

• Silicon carbide (SiC) possesses desirable properties for advanced electronic devices.
• Current SiC crystal growth methods have reduced macroscopic defects but still contain significant elementary dislocations.
• These remaining dislocations hinder the development of high-efficiency and reliable SiC electronic devices.

Purpose of the Study:

• To develop a novel method for reducing dislocation density in SiC single crystals.
• To enable the fabrication of virtually dislocation-free SiC substrates.
• To facilitate the advancement of high-power SiC electronic devices.

Main Methods:

• Inspired by the dislocation structures observed in SiC grown perpendicular to the c-axis (a-face growth).
• Implemented a new growth technique to minimize dislocation formation and propagation in SiC single crystals.

Main Results:

• Reduced the density of elementary dislocations in SiC single crystals by two to three orders of magnitude.
• Achieved virtually dislocation-free SiC substrates.
• Demonstrated a significant improvement in crystal quality compared to conventional methods.

Conclusions:

• The developed method offers a pathway to producing high-quality, low-dislocation SiC substrates.
• These substrates are crucial for realizing high-performance SiC electronic devices.
• The advancement promises reduced energy losses in future electrical systems utilizing SiC technology.