Ultra-low loss silicon nitride becomes even cooler

Area of Science:

• Materials Science
• Photonics
• Semiconductor Manufacturing

Background:

• Silicon nitride (SiN) is a key material for photonic integrated circuits (PICs) due to its low optical loss.
• Achieving ultra-low loss in SiN is crucial for advancing PIC technology.
• Current fabrication methods may have limitations for widespread integration.

Purpose of the Study:

• To develop an ultra-low loss silicon nitride fabrication process.
• To ensure compatibility with existing complementary metal-oxide-semiconductor (CMOS) manufacturing.
• To facilitate the broader adoption of SiN in PICs.

Main Methods:

• Utilized deuterated precursors for silicon nitride deposition.
• Employed low thermal budget processes compatible with backend-of-line CMOS fabrication.
• Characterized optical loss and material properties.

Main Results:

• Achieved ultra-low optical loss in silicon nitride waveguides.
• Demonstrated process compatibility within standard CMOS backend-of-line conditions.
• Fabrication is amenable to mass production.

Conclusions:

• Deuterated precursors and low thermal budgets enable ultra-low loss silicon nitride.
• The developed process accelerates the potential for widespread use of SiN in PICs.
• This advancement supports the integration of photonics with electronics.