Silicon carbide nano-via arrays fabricated by double-sided metal-assisted photochemical etching

Silicon carbide (SiC) has gradually dominated the market of power semiconductor electronic devices because of its excellent electrical properties and chemical stability. However, fabricating micro/nano structures in SiC that are crucial for device functioning has been challenging. In this paper, a novel double-sided metal-assisted photochemical etching (double-sided MAPCE) was proposed to efficiently fabricate SiC nano-via arrays. The experimental results demonstrated that the vertical etching rate of double-sided MAPCE was similar to 2.2 times higher than that of traditional MAPCE. The etching rate of SiC was found to be closely related to the type of noble metal, the concentration of oxidant (H2O2) and the UV light power density. The mechanism of double-sided MAPCE was disclosed as that the bottom noble metal layer catalyzed the reduction of H2O2, therefore, a built-in electric field was created which separated the photogenerated electron-hole pairs, thus, more photogenerated holes participated in oxidation of SiC resulting in improved SiC etching rate. The proposed method is possible to be used to process wide bandgap semiconductors.

Automated summary

A novel double-sided metal-assisted photochemical etching (double-sided MAPCE) technique was proposed to efficiently fabricate SiC nano-via arrays. The experimental results showed that the vertical etching rate of double-sided MAPCE was about 2.2 times higher than that of traditional MAPCE. The etching rate of SiC was closely related to the type of noble metal, the concentration of oxidant (H2O2), and the UV light power density. The proposed method is possible to be used to process wide bandgap semiconductors.