The transformation of a hydrophilic surface to a hydrophobic surface due to chemical modification and periodic nano pattern formation on silicon surface by 5–12 keV N⁺ ion bombardment is reported. The reactive N⁺ ion bombardment at oblique angle incidence leads to form silicon nitride (Si₃N₄) on the surface. Also, a periodic wave-like ripple pattern is formed on Si surface at nanoscale range whose wavelength and surface roughness can be regulated by varying the ion energy (5–12 keV). It is found that the contact angle of water droplet on such patterned surface increases with the increase of ripple wavelength and surface roughness. In contrast, the contact angle does not change for the same energy Ar⁺ bombarded Si surfaces, where such type of surface nano patterns are absent and also surface roughness remains almost the same. The morphologies of the irradiated and un-irradiated Si surfaces are examined by Atomic Force Microscopy (AFM), whereas the surface chemical composition is investigated by X-ray photoelectron spectroscopy (XPS). The chemical modification in terms of Si₃N₄ formation on the surface, periodic wave-like ripple pattern formation and high increase of root mean square (rms) roughness for N⁺ bombarded Si surfaces result in hydrophilic to hydrophobic transformation. The tuning of wettability in terms of ion beam parameters for the patterned and chemically modified Si surfaces is discussed in detail.

据报道，由于化学修饰和5-12 keV N ⁺离子轰击在硅表面形成周期性的纳米图案，亲水性表面转变为疏水性表面。倾斜角入射下的反应性N ⁺离子轰击导致在表面上形成氮化硅（Si ₃ N ₄）。同样，在纳米级的Si表面上形成周期性的波纹状波纹图案，其波长和表面粗糙度可以通过改变离子能量（5–12 keV）来调节。已经发现，水滴在这样的图案化表面上的接触角随着波纹波长和表面粗糙度的增加而增加。相反，对于相同的能量Ar ⁺，接触角不会改变轰击的Si表面，其中没有这种类型的表面纳米图案，并且表面粗糙度几乎保持不变。通过原子力显微镜（AFM）检查被辐照和未辐照的Si表面的形貌，而通过X射线光电子能谱（XPS）研究表面化学成分。N ⁺轰击的Si表面的表面Si ₃ N ₄形成，周期性波浪状波纹图案形成以及根均方根（rms）粗糙度的大幅增加等化学修饰导致亲水性向疏水性转变。详细讨论了针对图案化和化学改性的硅表面的离子束参数方面的润湿性调整。