Evolution of hydrogen and helium co-implanted single-crystal silicon during annealing

Abstract

H + was implanted into single-crystal silicon with a dose of 1×1016/cm2 and an energy of 30 KeV, and then He+ was implanted into the same sample with the same dose and an energy of 33 KeV. Both of the implantations were performed at room temperature. Subsequently, the samples were annealed in a temperature range from 200 to 450 °C for 1 h. Cross-sectional transmission electron microscopy, Rutherford backscattering spectrometry/channeling, elastic recoil detection, and high resolution x-ray diffraction were employed to characterize the strain, defects, and the distribution of H and He in the samples. The results showed that co-implantation of H and He decreases the total implantation dose, with which the surface could exfoliate during annealing. During annealing, the distribution of hydrogen did not change, but helium moved deeper and its distribution became sharper. At the same time, the maximum of the strain in the samples decreased a lot and also moved deeper. Furthermore, the defects introduced by ion implantation and annealing were characterized by slow positron annihilation spectroscopy, and two positron trap peaks were found. After annealing, the maximum of these two peaks decreased at the same time and their positions moved towards the surface. No bubbles or voids but cracks and platelets were observed by cross-sectional transmission electron microscopy. Finally, the relationship between the total implantation dose and the fraction of hydrogen in total implantation dose was calculated.

Inverted Pyramidal Texturing of Silicon Through Blisters in Silicon Nitride

“…In order to improve the robustness of the film against the etching solution, silicon nitride was deposited at a higher temperature of 250 • C, and to improve the fraction of open blisters, an inert gas plasma pretreatment prior to silicon nitride deposition is proposed. It was previously reported by Duo et al that by coimplanting helium and hydrogen into silicon, the smart cut process can be carried out more efficiently [28]. A reduction in implant dose, implant time, and lower crystal damage were reported as the benefits of helium-hydrogen coimplant [28].…”

Thermodynamic model of helium and hydrogen co-implanted silicon surface layer splitting

“…He can induce a high pressure in the microcracks [3]. It has been reported that fluences of 1 Â 10 16 He + /cm 2 + 0.75 Â 10 16 H + /cm 2 can effectively induce layer splitting, while a fluence of 5 Â 10 16 H + /cm 2 is needed for H implantation alone [4]. Therefore, it greatly decreases the H fluence needed for layer splitting.…”

Defect-related light emission from processed He-implanted silicon

“…During short time annealing the total amount of helium did not change substantially until reaching temperature exceeding 720 K [1,[4][5][6][7][8].…”