The effects of MeV energy He and N pre-implantation of Si substrate on the structure of porous silicon formed by anodic etching were studied by measuring the depth profiles of 15N decorating the pores walls. Radiation damage was recovered by annealing after the implantation. It was found that the He implant accelerates the etching process, probably due to the bubbles or the remaining lattice damage. At a dose of 8×1016ions/cm2 the He containing layer was formed with a significantly enhanced porosity due to the contribution of the large-sized bubbles. At the highest dose of 32.5×1016ions/cm2 flaking took place during the anodic etching. In contrast to He, N stopped the anodic etching at a depth of critical N concentration of ∼0.9 at.%. For the lowest implantation dose, where the peak concentration was below this limit, the pores propagate through the implanted layer with an enhanced speed.
|Number of pages||8|
|Journal||Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms|
|Publication status||Published - Jun 1 2001|
ASJC Scopus subject areas
- Nuclear and High Energy Physics