1：Experimental Design and Method Selection:

The study uses femtosecond laser pulses (800 nm, 120 fs, 1 kHz) to irradiate crystalline silicon submerged in ethanol. The effects of laser pulse energy and fabrication parameters (scanning speed and superimposing writing) on the morphology and amorphization are investigated.

2：Sample Selection and Data Sources:

Commercially available two-side polished P-type (boron doped) <100> oriented silicon wafers are used as substrates.

3：List of Experimental Equipment and Materials:

A linearly-polarized femtosecond pulse laser (UpTek Solutions, model: Phidia-c) with central wavelength of 800 nm, a pulse length of 120 fs, and repetition rate of 1 kHz is used. The laser beam is focused by a 10X objective lens (NA =

4：28 and WD = 0 mm). Experimental Procedures and Operational Workflow:

The laser pulse energy is adjusted by a combination of λ/2 plate and Glan-Taylor calcite polarizer. The interval of adjacent writing circle and writing speed are controlled by a galvanometric scanner.

5：Data Analysis Methods:

The morphology and the hierarchical micro/nanostructure are investigated by a field emission scanning electron microscope (SEM, Hitachi S-4800). The topography is investigated by an atomic force microscopy (AFM). The amorphization is recorded on a micro Raman imaging spectrometer (DXRxi).