Influence of fluorine on the simulation of the transient enhanced diffusion of 15 keV BF2+ ion implantation into silicon

Reduction of Boron Diffusion in Silicon–Germanium by Fluorine Implantation

“…3. Alternatively, the co-location of the fluorine and boron in the SiGe layer could suggest a chemical interaction between fluorine and boron as has been proposed for fluorine and boron in silicon [13], [16], [23]. If the fluorine-boron interaction in SiGe was stronger than that seen in Si, this might also explain the accumulation of fluorine in the SiGe layer.…”

Effect of fluorine implantation dose on boron thermal diffusion in silicon

“…As discussed in the introduction, several alternative mechanisms have been proposed to explain the effect of fluorine in suppressing the transient enhanced diffusion of boron, including a chemical interaction between boron and fluorine, 4,9,11,14,16 the presence of vacancy-fluorine cluster 13,17,18,25 and the interaction of fluorine with interstitials. 2,4-10, 18 The possibility of a chemical interaction between boron and fluorine can be discounted, since the shallow fluorine peak is seen whether or not a boron marker layer is present, as shown in Figs.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] This research has been motivated by the requirement in advanced CMOS technologies to minimize boron diffusion for the formation of shallow source/drain junctions and sharply defined halo profiles. 19,20 The minimization of boron diffusion is also important in bipolar transistors, where boron diffusion limits the achievable base width and hence the value of cutoff frequency that can be obtained.…”

“…1,7,8 In later work 2-6,9-15,17,18 fluorine was implanted separately to the boron to characterize the effect of the fluorine on boron diffusion. This work showed that the fluorine implant reduced boron transient enhanced diffusion [2][3][4][5]9,11,13,14,[16][17][18] and increased boron activity. 2 However, there have also been contradictory reports in the literature, which showed that fluorine implants had little or no effect on boron transient enhanced diffusion 10 and that fluorine enhanced boron diffusion in preamorphized silicon 6 using a silicon implant.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] A chemical interaction between boron and fluorine has been proposed to explain the suppression of boron transient enhanced diffusion by fluorine, 4,9,11,14,16 in which the fluorine combines with interstitial boron reducing its mobility 4,11,14,16 or reduces the probability of formation of a boron interstitial pair. 9,11 Alternatively, the formation of vacancy-fluorine complexes has been proposed, 13,17,18,[23][24][25][26] which act as a barrier for boron diffusion, 13 or suppress the interstitial concentration and hence reduce boron transient enhanced diffusion 17 and thermal diffusion.…”