Ultrafast fabrication of high-aspect-ratio macropores in P-type silicon: toward the mass production of microdevices

Abstract

Etching rate is a major concern for the effective mass production of high-aspect-ratio microstructures, especially in p-type silicon. In this work, controlled electrochemical growth of high-aspect-ratio (from 15 to 110) macropores in p-type silicon at ultrafast etching rate (from 16 to 30 µm min−1) has been studied. Based on current-burst-model, pore formation was systematically investigated from the nucleation phase to stable pore growth. Good macropores with depth up to 180 µm and aspect ratio beyond 110 was achieved in just 11 min. This sets a new record on state-of-the-art p-type silicon microfabrication and can promote the development of microdevices.

Keywords

• Ultrafast fabrication
• P-type macropore
• high aspect ratio
• mass production
• nucleation phase