Stability of cavities formed by He+ implantation in silicon

Influence of dose rate on bubble formation by high energy He implantation in silicon

“…6 MeV, 2ϫ10 16 cm Ϫ2 ͒. After implantation the samples were subjected to thermal annealing at 800°C for 30 min.…”

Characterisation of nanocavities in He+-implanted silicon by transmission electron microscopy and small-angle X-ray scattering

“…In the very first publications on this subject, Griffioen et al [3,4] reported that the as-implanted microstructure consists in a very high density of helium bubbles in the range 2-3 nm. As other groups [23], our measurements did not allow us to quantify both the density and the size of the nanocavities in the keV as-implanted sample with such a precision.…”

Roles of Impurities and Implantation Depth on He+- Cavity Shape in Silicon

“…The latter mechanism must be applied to a conservative system and thus should be greatly limited by the loss of V at the sample surface. According to nuclear reaction analysis (NRA), the desorption rate decreases significantly in the early stage of annealing [15,16]. These results suggest that He atoms remain in the sample even after high temperature annealing.…”

“…These results suggest that He atoms remain in the sample even after high temperature annealing. The parameters which can control the cavity growth are numerous: the local concentrations of V and self-interstitial at Rp, the distance between the cavities and the surface and the impurity concentration in the Si matrix [15,[7][8][9][10][11][12][13][14][15][16][17][18][19][20]. So far, the nucleation and growth mechanisms of cavities are still unclear and under debate.…”

“…The first part of this paper deals with the determination of the equilibrium shape of the cavities induced by an implantation of 5.00×10 16 He + cm -2 , at 1.55 MeV, for different annealing temperatures up to 1050°C. In the second and third part, the determination of the cavity shape is used as a tool to check the chemisorption mechanism and the possible role of He in the cavity growth.…”