Simulation Analysis Of The Microscopic Effects Of Focused Ion Beam Etching On Silicon Surface

Focused ion beam(FIB)is an advanced technology combining the functions of microfabrication and microanalysis which can maskless manufacture with high precision and modify different materials.The FIB etching silicon is the research object of this paper.The process of ion implantation and ion sputter and their crystal face effects are studied respectively.The crystal face effects of FIB sputtering different silicon substrates are explored by experimental methods,and the causal hypotheses of crystal face effects are proposed.The simulation models of ion implantation and ion sputter are established by the molecular dynamics(MD)method.Through the analysis of particle distribution and the study of the simulated morphology,the microcosmic mechanism of ion and substrate silicon atoms is deeply understood.The crystal face effects are verified and the validity of the simulation models is verified simultaneously.Based on this,the causal hypotheses of crystal face effects are analysed and verified.The main research work is as follows:1.The crystal face effects phenomenon of FIB sputtering different silicon substrates is obtained.And it is concluded that the crystal face effects of sputter etching are directly related to the sputter yield and the crystal structure of the silicon substrate.It is assumed that the atomic arrangement differences of the substrate affect the energy transfer between the incident ions and the substrate atoms.And the differences of the sputter morphology are positively correlated with the sputter yield.2.Based on the theory of the interaction between FIB and the surface of solid material,the simulation models of ion implantation and ion sputter are established by molecular dynamics method.And the definitions of the properties of analyzing MD simulation results and their calculation methods are clarified.3.The microscopic mechanism of the interaction between ions and the substrate silicon atoms is deeply understood by taking the simulation process of single gallium ion and substrate silicon atoms as the entry point.The amorphous process and the crystal face effects of ion implantation of silicon substrate are studied by analyzing the CNA defects through the common neighbor analysis(CNA)method.The established simulation models are verified to be accurate and effective through the comparison between the simulation results and the experimental results.4.The process of FIB sputter etching different silicon substrates are detailed analyzed.The crystal face effects of ion sputter are studied from the differences of sputter morphology,sputter yield and gallium ions and CNA defects distributions.The causes of crystal face effects are analyzed,and the proposed hypothesis is verified.