The Influence of Etching Sequence on Morphology in Deep Silicon Etching

The cycli etching process is mainly used for silicon etching, which can achieve a large aepect ratio and selectivity ratio. The article uses CL2/Ar ase the main etching gas, O2 as the passivation gas, and CF4/CHF3 as the gas for opening the bottom of passivation layer. The result show that the silicon sidewall angle ≥ 96°, the silicon sidewall is continuous, and there is no obvious fan-shaped roughness.