The Effect of Low-energy Plasma Bombardment on the Surface Properties of Monocrystalline Silicon

To investigate the effect of low-energy plasma bombardment on the surface physical properties of monocrystalline silicon. By controlling factors such as etching time and gas pressure inside the vacuum chamber, low-energy plasma is used to etch single-sided polished monocrystalline silicon (100). By measuring the etching depth, surface roughness, Raman spectroscopy, and contact angle of the silicon wafer after etching, the changes in the physical properties of the silicon wafer surface are studied. The experimental results show that as the etching time increases, the etching depth of the silicon wafer remains basically unchanged, while as the etching pressure increases, the etching depth of the silicon wafer first decreases and then increases. When the etching current is 0.1 A and the gas pressure is 2 mTorr, the surface roughness of the silicon wafer reaches a minimum value at an etching time of 40 s. The Raman spectra of the etched silicon wafers were measured, and it was found that the Raman second-order peak decreased slightly overall with increasing etching time. Silicon wafers were etched using argon ions and nitrogen ions respectively, and it was found that both showed varying degrees of increase in droplet angle after being stored in air for a period of time. The etched silicon wafers were stored separately in argon, nitrogen, and air environments, and the trend of water droplet angle changes on the surface of the silicon wafers was almost identical. Low temperature plasma bombardment has no significant effect on the thickness of silicon wafers in a short etching time, but has a certain effect on improving the surface roughness of silicon wafers and reducing the wettability of silicon wafers. Among them, silicon wafers treated with argon ion bombardment undergo a transition from hydrophilicity to hydrophobicity after being stored for a period of time.