Magnetic Enhanced Inductively Coupled Plasma Etching of 6H-SiC

Silicon carbide(SiC) is one of the attractive semiconductor materials due to its high temperature stability and high thermal conductivity for electronic devices operating at high temperature and high power levels. Due to its excellent electrical, thermal, and mechanical properties, the SiC is also used as the substrate for microelectromechanical system (MEMS). However, high rate and anisotropic plasma etching is a prerequisite for the application of SiC to these device fabrications. In this study, SiC was etched using a magnetic enhanced inductively coupled plasma (MEICP) in fluorine containing gases such as NF₃, SF₆, and CF₄, and over than 2 /min of high etch rate could be obtained in SF₆ based plasmas. The etch characteristics of SiC and etch selectivities over mask materials such as photoresist and metals (Al, Ni, Cu, etc.) were also investigated as a function of operating pressure, inductive power, and applied dc bias voltage to the substrate, etc.. The etch characteristics were investigated using an optical emission spectroscopy (OES) and quadrupole mass spectrometer (QMS). The etch profiles of patterned SiC were observed by a scanning electron microscopy (SEM).