Temperature dependence of hydrogen-induced exfoliation of InP

Abstract

To investigate the mechanisms of hydrogen-induced blistering in III–V materials, a standard splitting dose of $5\times {10}^{16}{\mathrm{H}}_2^{+}∕{\mathrm{cm}}^2$ at $150\mathrm{keV}$ was implanted into $\mathrm{InP}$ substrates cooled to $-20°\mathrm{C}$ . Substrate cooling during the implantation improved the reproducibility of this approach by limiting hydrogen mobility during ion implantation. The implant profile and defect structure of unbonded wafers were studied for various annealing schedules with double-axis x-ray diffraction and transmission electron microscopy. It was found that exfoliation was greatly facilitated by a combined lower-temperature $\left(150°\mathrm{C}\right)$ “defect nucleation” step, followed by a higher-temperature anneal $\left(300°\mathrm{C}\right)$ . The nucleation of defects in the lower-temperature regime, which did not occur if the initial anneal was conducted only at higher temperatures, was attributed to defect trapping of hydrogen. This annealing sequence presents a means by which to (i) improve the interfacial bond strength at low temperatures while the “nucleation” occurs and (ii) promote efficient exfoliation at high temperature.