SiC Cantilevers For Generating Uniaxial Stress

TL;DR

This paper introduces SiC cantilever beam resonators fabricated from high purity semi-insulating 4H Silicon Carbide wafers, demonstrating high mechanical quality factors and the ability to generate significant uniaxial surface stress at resonance.

Contribution

It presents a novel fabrication process for SiC beam resonators with high Q factors and quantifies their uniaxial surface stress generation capabilities.

Findings

Mechanical Q factors > 10,000 achieved

Resonance frequencies from 300 kHz to 8 MHz

Uniaxial surface stress of 20 MPa at resonance

Abstract

This paper demonstrates the first beam resonators fabricated from bulk high purity semi-insulating 4H Silicon Carbide wafers (HPSI 4H-SiC). Our innovations include: (1) Multi-level front-side, back-side inductively coupled plasma-deep reactive ion etching (ICP-DRIE) technology to fabricate thin, low-mass, bending-mode resonators framed by the SiC substrate (2) Laser Doppler Vibrometer (LDV) measurements of mechanical quality factors (Q) > 10,000 with frequencies ranging from 300 kHz to 8MHz and (3) Calculated uniaxial in-plane surface stress 20 MPa at top surface of resonator base when operating at resonance in vacuum.