Single-Crystalline 3C-SiC anodically Bonded onto Glass: An Excellent Platform for High-Temperature Electronics and Bioapplications

Abstract

Single-crystal cubic silicon carbide has attracted great attention for MEMS and electronic devices. However, current leakage at the SiC/Si junction at high temperatures and visible-light absorption of the Si substrate are main obstacles hindering the use of the platform in a broad range of applications. To solve these bottlenecks, we present a new platform of single crystal SiC on an electrically insulating and transparent substrate using an anodic bonding process. The SiC thin film was prepared on a 150 mm Si with a surface roughness of 7 nm using LPCVD. The SiC/Si wafer was bonded to a glass substrate and then the Si layer was completely removed through wafer polishing and wet etching. The bonded SiC/glass samples show a sharp bonding interface of less than 15 nm characterized using deep profile X-ray photoelectron spectroscopy, a strong bonding strength of approximately 20 MPa measured from the pulling test, and relatively high optical transparency in the visible range. The transferred SiC film also exhibited good conductivity and a relatively high temperature coefficient of resistance varying from -12 000 to -20 000 ppm/K, which is desirable for thermal sensors. The biocompatibility of SiC/glass was also confirmed through mouse 3T3 fibroblasts cell-culturing experiments. Taking advantage of the superior electrical properties and biocompatibility of SiC, the developed SiC-on-glass platform offers unprecedented potentials for high-temperature electronics as well as bioapplications.

Strain Effect in Highly‐Doped n‐Type 3C‐SiC‐on‐Glass Substrate for Mechanical Sensors and Mobility Enhancement

“…Using Depth profile X‐ray photoelectron spectroscopy the bonding layer was found to be less than 15 nm. The bonding strength was characterized using a pulling test, showing a large tensile strength above 20 MPa, which is excellent for mechanical sensing . Subsequently, the top Si layer with a thickness of 650 µm was completely removed in KOH at 80 °C.…”

Ultraviolet and Visible Photodetection Using 3C-SiC/Si Hetero-Epitaxial Junction

“…Among 200 polytypes of SiC, only 3C-SiC can be grown epitaxially on a large Si-wafer at around 1000 C. As a result, the cost of the wafer reduces significantly [10]. Hence, the 3C-SiC on Si structure has been used for a number of N/MEMS applications, for instance, temperature sensors [11]- [12], piezoresistive sensors [13]- [15], and pressure sensors [16]- [17].…”

Utilizing large hall offset voltage for conversion free 4H-SiC strain sensor

“…In contrast, silicon carbide (SiC) is of interest for high power electronics devices, and high temperature applications owing to its wide energy-band gap, high break-down voltage, thermal stability, and excellent chemical innerness [6]. Taking advantage of these superior properties and the availability of SiC wafers, many SiC-based MEMS mechanical sensors have been developed for harsh operating environments [7][8][9][10].…”