Impact of He and H relative depth distributions on the result of sequential He+ and H+ ion implantation and annealing in silicon

Abstract

Sequential He++H+ ion implantation, being more effective than the sole implantation of H+ or He+, is used by many to transfer thin layers of silicon onto different substrates. However, due to the poor understanding of the basic mechanisms involved in such a process, the implantation parameters to be used for the efficient delamination of a superficial layer are still subject to debate. In this work, by using various experimental techniques, we have studied the influence of the He and H relative depth-distributions imposed by the ion energies onto the result of the sequential implantation and annealing of the same fluence of He and H ions. Analyzing the characteristics of the blister populations observed after annealing and deducing the composition of the gas they contain from FEM simulations, we show that the trapping efficiency of He atoms in platelets and blisters during annealing depends on the behavior of the vacancies generated by the two implants within the H-rich region before and after annealing. Maximum efficiency of the sequential ion implantation is obtained when the H-rich region is able to trap all implanted He ions, while the vacancies it generated are not available to favor the formation of V-rich complexes after implantation then He-filled nano-bubbles after annealing. A technological option is to implant He+ ions first at such an energy that the damage it generates is located on the deeper side of the H profile.

Study of surface exfoliation induced by hydrogen implantation and annealing in GaSb (100) substrates

“…Reboh. et al [30] and more recently, Cherkashin et al have discussed in detail this behaviour in H-implanted silicon [31]. Following implantation, numerous defect complexes are formed.…”

Microstructure Evolution in He-Implanted Si at 600 °C Followed by 1000 °C Annealing

“…In order to decrease the implantation dose, H+ and He+ ions are used; helium incorporates and over-pressurizes the hydrogen platelets during annealing and thus promotes their more effective mechanical coalescence and the formation of blisters [ 13 , 14 ]. The smart-cut process depends on different parameters, such as temperature and annealing time [ 8 ], He and H fluences [ 14 ], the He to H fluences ratio [ 15 ], He and H relative depth distributions (imposed by respective ion energies [ 16 ]) and the relative order of He and H implantation [ 17 ]. In the early period, most interest in the applications of this method was devoted to studying helium bubble formation and evolution in semiconductors [ 18 , 19 , 20 , 21 , 22 , 23 ].…”

Effects of He+ and H+ Co-Implantation with High Energy on Blisters and Craters of Si and SiO2-On-Si Wafers

“…In 2016, Cherkashin et al [13] studied the characteristics of Si(001) wafers covered by a 25 nm-thick top SiO 2 layer and compared the defect microstructures after annealing under different implantation sequences of 12 keV, 7 × 10 15 He + /cm 2 and 6 keV, 6 × 10 15 H + /cm 2 . In 2018, Cherkashin et al [14] investigated the influences of He + and H + relative depth distribution on blisters and exfoliation on surface with a 25 nm-thick top SiO 2 layer. Since the top SiO 2 layer mentioned above was relatively thin, the implantation energies of He + and H + ions needed were just several dozens of keV.…”