Research on the measurement of wet etching rates and Level Set simulation of patterned sapphire substrates

Abstract The complex anisotropic nature of sapphire wet etching significantly impedes the preparation of patterned sapphire substrates. This paper investigates the measurement of wet etching rates and Level Set simulation of patterned sapphire substrates to advance their application. The study introduces a segmented hemispherical measurement method and corresponding experimental apparatus to measure the etching rates of complete crystal planes of sapphire. The accuracy of these measurements is analyzed using the Wulff–Jaccodine method. Subsequently, C -plane sapphire substrates with various masks undergo wet etching using a designed wafer insertion-type rotary experimental device, and the etched structures are simulated using the Level Set method. The findings demonstrate that the proposed measurement method effectively prevents shallow etching and over etching phenomena of the hemisphere, yielding accurate etching rates of complete crystal planes. The experimental device successfully prevents micro-mask etching and ensures proper wet etching of wafers. The simulated results closely align with experimental outcomes, potentially reducing the design and preparation cycle of patterned sapphire substrates while minimizing costs.