Elucidation of Surface Nano-hillocks by Localized Plasma Expansion

For the time being, the creation of surface nano-structures has become an important technological process which plays a paramount role in the electronic devices, as it has a very remarkable feature that they are used in etching without using chemicals. Irradiation of silicon oxide single crystal with slow highly charged ions can produce surface nano-hillocks. The formation mechanism of the created nano-hillocks is a topic of debate. One of the suggested formation mechanisms is a plasma expansion approach. The latter will be used to explain the creation of surface nano-hillocks in silicon oxide single crystal using a fully classical plasma model. For this purpose, classical hydrodynamic ion fluid equations along with Maxwellian or non-Maxwellian electrons distributions are solved numerically to obtain the expansion profiles of the number density, fluid velocity, and electrostatic potential. The relevance of different plasma parameters such as temperature and density ratios, superthermal, and non-extensive parameters is highlighted on the expansion profiles.