A rapid and cost-effective metallization technique for 3C-SiC MEMS using direct wire bonding

Area of Science:

• Materials Science
• Electrical Engineering
• Microelectromechanical Systems (MEMS)

Background:

• Traditional wire bonding for silicon carbide (SiC) MEMS devices often requires complex metal deposition and etching processes.
• Achieving reliable electrical contacts on SiC surfaces for device characterization presents a significant challenge.

Purpose of the Study:

• To present a novel, simple, rapid, and cost-effective wire bonding technique for single crystalline silicon carbide (3C-SiC) MEMS devices.
• To demonstrate the feasibility of direct aluminum wire bonding onto SiC films without additional fabrication steps.

Main Methods:

• Utilized direct ultrasonic wedge-wedge bonding to join aluminum wires directly onto 3C-SiC films.
• Characterized the bonded joints for adhesion force and electrical contact properties.
• Fabricated and tested a 3C-SiC strain sensor as a proof of concept.

Main Results:

• Achieved strong adhesion forces of 12.6-14.5 mN between Al wires and SiC surfaces.
• Demonstrated excellent and stable ohmic contact, even at temperatures above 420 K.
• The developed 3C-SiC strain sensor exhibited high sensitivity, excellent repeatability, and reliable electrical contact via the direct bonding method.

Conclusions:

• The proposed direct ultrasonic wire bonding technique is a simple and effective method for contacting SiC MEMS devices.
• This approach eliminates the need for metal deposition and etching, reducing fabrication complexity and cost.
• The technique shows significant potential for various SiC-based MEMS and microelectronic applications.