A four level silicon microstructure fabrication by DRIE

Abstract

We present a four level Si microstructure fabrication process with depths ranging from 70–400 μm. All four levels are etched from the same side, by using four hard masks (, Al, AZ4562 photo resist, and Al). The choice of the hard masks and their relative selectivity will be discussed. Also two different deep reactive ion etching (DRIE) processes, performed in two different machines, are compared and evaluated. The process evaluation and discussions are based on the vertical walls deviation from a right angle, the surface roughness and the resolution. In the end, a solution is proposed to remove spikes and grassing which appeared during both DRIE processes, and the impact of removing them from the surfaces is discussed.

Self-Controlled Cleaving Method for Silicon DRIE Process Cross-Section Characterization

“…In addition, one should pay attention to ARDE (Aspect Ratio Dependent Etching) and microloading effects i.e., the influence of microstructure topology (different widths and The Bosch process deep silicon etching (hundreds of microns deep) with a high aspect ratio (>20) requires an appropriate choice of protective mask. There are several materials compatible with dry etching processes and suitable for this purpose (Figure 2): silicon dioxide and silicon nitride, metal masks, and photoresists [15][16][17][18][19][20][21][22][23][24]. Particular mask choice can depend on not only selectivity but relies on available equipment and materials in the laboratory.…”

Nanosecond pulsed laser ablation of silicon—finite element simulation and experimental validation

“…Taking the unique chemical, physical and mechanical properties of silicon into consideration, it remains challenging to fabricate precise surface textures at low cost. Different techniques including lithography [5,6], etching [7][8][9][10][11][12], electrical discharge machining [13] and focused ion-beam machning [14] have been utilized to fabricate surface textures on silicon with feature sizes ranging from nano-to micrometers. However, lithography typically has the drawback of high costs involved while uniformity and homogeneity are critical texturing issues related to methods based upon chemical reactions.…”