Rapid Plasma Etching for Fabricating Fused Silica Microchannels

Area of Science:

• Materials Science
• Microfabrication
• Chemical Engineering

Background:

• Microchemical and biochemical systems on a chip require advanced microfabrication techniques.
• Conventional wet etching methods for microstructures have limitations in device engineering applications.

Purpose of the Study:

• To develop a novel, cost-effective method for fabricating microchannels in fused silica.
• To overcome the limitations of traditional microfabrication techniques for fused silica.

Main Methods:

• Utilized photoresist and plasma etching with C3F8, CHF3, and Ar gases.
• Fabricated deep, rectangular microchannels with near-90° vertical angles on a fused silica substrate.

Main Results:

• Achieved microchannels with 10 μm depth and surface roughness below 1 nm.
• Obtained high etching rates of 5-7 nm/s.
• Demonstrated a metal-free fabrication process.

Conclusions:

• The developed plasma etching technique offers a low-cost, simple, and effective method for fused silica microstructuring.
• This advancement is crucial for improving micro-systems-on-a-chip performance.
• The metal-free approach broadens applications in microfluidics and biochemical systems.