A novel process for circle-like 3D microstructures by two-step wet etching

This paper presents a novel technique for developing new structures on a Si substrate used in micro electro mechanical systems. The technique does not require any compensating structure for the fabrication of circle-like 3D microstructures, as reported in the literature. We design a two-step wet etching process and the results show that the application of the technique can lead to an optimal etching process in a more effective manner for the realization of circle-like 3D microstructures, based on a mixture of 5M KOH solution with 20% by volume isopropyl alcohol (IPA) etching at 80 degrees C for 80 min and then isotropic etching in HF-HNO(3) at room temperature for 3 min.