Comparative analysis of surface morphologies for porous structure development under ion beam irradiation in GaSb, InSb, and Ge

Abstract

In this study, ion beam irradiation was applied to GaSb, InSb, and Ge surfaces under the same conditions to form porous structures ranging from nanoscale to submicrometer scale. Such structures result from the migration of point defects generated by cascade damage and from redeposition induced by sputtering. By comparing the structural changes in these three materials, the dominant mechanisms underlying the formation of a porous structure were investigated. The results indicated that point defect migration plays a primary role in GaSb and Ge, whereas redeposition by sputtering is the main factor influencing InSb. Furthermore, oblique ion irradiation of GaSb confirmed that sputtering contributes to structural formation, indicating that multiple mechanisms may act simultaneously. In addition, the reasons why these phenomena are observed only in limited materials such as GaSb, InSb, and Ge were examined by classifying structure formation (presence or absence) using material properties through logistic regression analysis. Consequently, the melting point was found to influence structure formation.