Structuring of Si into Multiple Scales by Metal-Assisted Chemical Etching

Area of Science:

• Materials Science and Engineering
• Nanotechnology
• Surface Chemistry

Background:

• Structuring silicon (Si) is critical for numerous advanced applications.
• Metal-assisted chemical etching (MaCE) is a versatile, cost-effective, and scalable technique for Si structuring across dimensions.
• MaCE process control relies on optimizing parameters like catalyst, substrate properties, and etchant composition.

Purpose of the Study:

• To review recent advancements in the Metal-assisted chemical etching (MaCE) process for silicon structuring.
• To critically discuss bulk-scale Si structuring using MaCE, including mass transport and etch control.
• To explore applications and future research directions for macroscale Si structures fabricated by MaCE.

Main Methods:

• Review of fundamental principles of Metal-assisted chemical etching (MaCE).
• Summary and critical discussion of bulk-scale Si structuring via MaCE.
• Analysis of mass transport schemes, etch directionality, uniformity, and side-etch suppression.

Main Results:

• Recent developments in MaCE enable fine control over Si macrostructure fabrication.
• Optimization of process parameters is crucial for successful and uniform Si structuring.
• Existing applications of macroscale Si structures are limited but demonstrate potential.

Conclusions:

• MaCE is a promising technique for fabricating macroscale silicon structures.
• Significant opportunities exist for macroscale Si structures in microfluidics, micro-total analysis systems, and microelectromechanical systems.
• Further research into macroscale MaCE of Si and its applications is warranted.