1：Experimental Design and Method Selection:

The study used metal-assisted chemical etching (MACE) with an applied electric field to fabricate silicon micro/nano-structures. The rationale was to control the motion of charged particles (holes) to accelerate etching and improve trench morphology. Theoretical models included chemical reaction principles and the Space Charge Region (SCR) model for doping effects.

2：Sample Selection and Data Sources:

Boron-doped p-type (100) silicon wafers with resistivity of 20-30 Ω·cm were used as substrates. Samples were prepared by coating with Ti and Au layers and etching in HF-H2O2 solution.

3：List of Experimental Equipment and Materials:

Equipment included a power supply (ITECH IT6834), electrolytic cell, electron beam evaporation system, thermal evaporation system, and field-emission scanning electron microscopy (FE-SEM, Zeiss Ultra Plus). Materials included silicon wafers, Ti, Au, HF, H2O2, acetone, ethanol, deionized water, photoresist, and graphite electrodes.

4：Experimental Procedures and Operational Workflow:

Silicon substrates were cleaned, coated with photoresist and metal layers (Ti and Au) via evaporation, patterned via lift-off, and etched in HF-H2O2 etchant with applied electric field (voltages varied from 5 to 40 V) for 20-30 minutes at room temperature. The electric field direction was varied by connecting Si to anode or cathode.

5：Data Analysis Methods:

Morphologies were examined using FE-SEM to measure trench depth and analyze etching rates. Data interpretation involved calculations of hole and HF concentrations based on doping levels and electric field effects.