Passivation and Maskless Processing with Anisotropic Etches in Silicon

Abstract

The passivation of silicon surfaces to anisotropic etches by ion and electron beams is demonstrated. The mechanisms for passivation is attributed to oxide growth induced by lattice damage and strain. Its application as a maskless etch process or etch stop for fabrication of nonplanar microstructures is discussed.

Anodic Passivation of {111} Silicon in KOH

“…Apparently, the only criteria is that a sufficient change in the silicon chemical potential is required to effect passivation. If the divalent film on {111} silicon extends loosely into the crystal lattice by atom or electron exchange and its concentration is greater than 10 TM atoms/cm 3, one could consider the Si +2 to have the same effect on the silicon passivation as that of a normal dopant atom (30). The change in the silicon chemical potential would then result in ocp passivation in the same way that a high boron or phosphorous concentration would.…”

Femtosecond Laser Direct Writing of Optical Overpass

“…However, 3D printing technology has higher requirements of materials, and the existing machining accuracy struggles to meet the high-precision manufacturing requirements of jumper wires. On the other hand, the two-photon femtosecond laser direct writing technology with high-energy pulses directly acts on the interior of the material to realize three-dimensional, nano-scale resolution and maskless processing [ 26 ] with arbitrary structure design. Because of nonlinear absorption characteristics [ 27 , 28 , 29 ], femtosecond laser-induced two-photon direct writing can not only achieve a resolution far beyond the optical diffraction limit [ 30 , 31 , 32 ] (below 10 nm), but also has a wide range of material processing capabilities, from soft polymer materials to hard materials such as metals, semiconductors, and dielectric materials.…”