Crack barriers for thick SiN using dicing.

Area of Science:

• Materials Science
• Photonics
• Optical Engineering

Background:

• Thick silicon nitride (SiN) waveguides are crucial for nonlinear optical applications due to their low dispersion properties.
• High-quality thick SiN deposition via chemical vapor deposition (CVD) is hindered by high internal stress, leading to cracking.
• Existing methods for crack-free SiN often involve complex crack barrier integration.

Purpose of the Study:

• To demonstrate a simple, single-step method for producing high-quality, crack-free thick silicon nitride waveguides.
• To evaluate the effectiveness of dicing trenches as a crack mitigation technique.
• To showcase the suitability of the fabricated SiN waveguides for nonlinear optical applications.

Main Methods:

• Fabrication of thick silicon nitride films using chemical vapor deposition (CVD).
• Integration of dicing trenches as a crack-preventing measure during the fabrication process.
• Characterization of waveguide quality, including optical loss measurements (<0.5 dB/cm).
• Demonstration of Kerr-comb generation in a silicon nitride ring resonator.

Main Results:

• Successfully produced crack-free thick silicon nitride waveguides using dicing trenches.
• Achieved high-quality waveguides with optical losses below 0.5 dB/cm.
• Confirmed the low dispersion characteristics suitable for nonlinear applications through Kerr-comb generation.

Conclusions:

• Dicing trenches provide an effective and simple single-step solution to overcome cracking issues in thick SiN waveguides.
• The fabricated waveguides exhibit high quality and low dispersion, enabling efficient nonlinear optical processes like Kerr-comb generation.
• This method facilitates the development of advanced photonic devices utilizing thick SiN for enhanced nonlinear performance.