Defect structure in self‐implanted silicon annealed under enhanced hydrostatic pressure – electron microscopy study

Abstract

The effect of hydrostatic pressure on crystal structure of annealed self-implanted silicon was investigated by transmission electron microscopy and scanning electron microscopy observation of selectively etched samples. 3°-angle bevel mechanical polishing allowed determining depth distributions of dislocations. The effect of enhanced hydrostatic pressure on recrystallization and dislocation evolution depending on annealing temperature was discussed. The structure of defects in annealed samples was correlated with photoluminescence spectra on the basis of transmission electron microscopy analysis. IntroductionThe damage, which is inherently introduced during implantation, results in the presence of dislocations after annealing, which can effectively reduce device performance. The defects which are formed during annealing of ion implanted silicon are well known and classified [1]. The influence of enhanced hydrostatic pressure on annealing of self-implanted silicon has been investigated recently by photoluminescence [2]. However, further studies were needed to determine the defect structure and its relation to the pressure applied during annealing.In this paper electron microscopy results are presented and correlated with photoluminescence data. The impact of enhanced pressure at different temperatures is discussed.

Structure of self-implanted silicon annealed under enhanced hydrostatic pressure

“…PL at about 0.81 eV, related to the presence of dislocations, was reported for Si:Si processed at up to 1270 K, especially under HP, evidencing the formation of dislocated crystalline areas near R p [2,3,5].…”

“…As-implanted Si:Si exhibits a layered structure [3,5]. In the presently investigated Si:Si, about an 80 nm thick near-surface layer was shot through by Si + ; the most damaged zone was placed near R p .…”

“…As stated earlier, hydrostatic pressure (HP) of ambient influences the recrystallization of aSi at high temperatures (HTs); such an approach delivers valuable information on solid-phase epitaxial re-growth (SPER) [2,3]. For a lot of systems, prepared by implantation with other ions (e.g.…”

Luminescent and Structural Properties of Self-Implanted Silicon Layers in Relation to their Fabrication Conditions

“…The main aspects of how luminescence centers and structural defects are formed in structures of this kind were summarized in [2]. Si ion implantation and subsequent annealing has been recently found to produce DRL in Si, too [3][4][5]. In the case of Si ions, the technological conditions in which DRL appears are essentially different from those for the rare earth ions.…”