Smart-cut layer transfer of single-crystal SiC using spin-on-glass

Abstract

The authors demonstrate "smart-cut"-type layer transfer of single-crystal silicon carbide (SiC) by using spinon-glass (SoG) as an adhesion layer. Using SoG as an adhesion layer is desirable because it can planarize the surface, facilitate an initial low temperature bond, and withstand the thermal stresses at high temperature where layer splitting occurs (800-900 °C). With SoG, the bonding of wafers with a relatively large surface roughness of 7.5-12.5 Å rms can be achieved. This compares favorably to direct (fusion) wafer bonding, which usually requires extremely low roughness (<2 >Å rms), typically achieved using chemical mechanical polishing (CMP) after implantation. The higher roughness tolerance of the SoG layer transfer removes the need for the CMP step, making the process more reliable and affordable for expensive materials like SiC. To demonstrate the reliability of the smart-cut layer transfer using SoG, we successfully fabricated a number of suspended MEMS structures using this technology. Smart-cut layer transfer of single-crystal SiC using spin-on-glass The authors demonstrate "smart-cut"-type layer transfer of single-crystal silicon carbide (SiC) by using spin-on-glass (SoG) as an adhesion layer. Using SoG as an adhesion layer is desirable because it can planarize the surface, facilitate an initial low temperature bond, and withstand the thermal stresses at high temperature where layer splitting occurs (800-900 C). With SoG, the bonding of wafers with a relatively large surface roughness of 7.5-12.5 Å rms can be achieved. This compares favorably to direct (fusion) wafer bonding, which usually requires extremely low roughness (<2 Å rms), typically achieved using chemical mechanical polishing (CMP) after implantation. The higher roughness tolerance of the SoG layer transfer removes the need for the CMP step, making the process more reliable and affordable for expensive materials like SiC. To demonstrate the reliability of the smart-cut layer transfer using SoG, we successfully fabricated a number of suspended MEMS structures using this technology. Disciplines Mechanical Engineering

Visible Photoluminescence from Cubic (3C) Silicon Carbide Microdisks Coupled to High Quality Whispering Gallery Modes

“…This makes 3C-SiC a favorable polytype for applications where direct integration with silicon is of interest, as well as for fabrication of planar devices based on films on a sacrificial layer. Obtaining slabs from bulk hexagonal polytypes is usually done by the Smart-Cut process, 13 which may cause surface roughness, as well as generate undesired impurities in the sample. In contrast, heteroepitaxial growth of cubic silicon carbide on silicon has superior sample properties.…”

Lithography and Etching‐Free Microfabrication of Silicon Carbide on Insulator Using Direct UV Laser Ablation

“…To overcome this obstacle, the SiC thin film can be bonded onto insulating substrates such as glass by wafer bonding to prevent current leakage at high temperature. [11][12][13] This platform provides a feasible development for SiC electronics, eliminating the leakage observed in SiC-on-Si electronics at high-temperature operations. Previously, we introduced an anodic bonding technique for as-grown SiCon-Si onto an insulating substrate (i.e., glass), indicating a great potential for SiC-based sensors and electronics for a wide range of application including biological utilizations.…”

“…However, the leakage of the electric current through the SiC–Si junction drastically increases with temperature, exposing a significant limitation for high‐temperature applications that SiC materials are used for. To overcome this obstacle, the SiC thin film can be bonded onto insulating substrates such as glass by wafer bonding to prevent current leakage at high temperature . This platform provides a feasible development for SiC electronics, eliminating the leakage observed in SiC‐on‐Si electronics at high‐temperature operations.…”

Nano Periodic Structure Formation in 4H–SiC Crystal Using Femtosecond Laser Double-Pulses

“…Such technique also employed for SiC wafer, which has advantages for mass production from its high throughput [5]. The other approach of smart cut method using proton also proposed to settle some negative issues for SiC substrate [6][7][8]. At the recent time, a stealth dicing method has been used to cut the fabricated semiconductor device chip on the wafer using an ultrashort pulse laser [9][10][11], this dicing technique has also attractive to improve the production for SiC applications [12,13].…”