Correlation between surface damage and micro-defects in Si covered with insulating layer by implantation of He and H ions

Cz n-type Si (100) wafers covered with a 220 nm SiO2 layer or a 170 nm Si3N4 layer were singly implanted with 160 keV He ions at a dose of 5 × 1016/cm2 or successively implanted with 160 keV He ions at a dose of 5 × 1016/cm2 and 110 keV H ions at a dose of 1 × 1016/cm2. Surface morphologies together with defect microstructures have been studied by means of several techniques, including optical microscopy, atomic force microscopy, and cross-sectional transmission electron microscopy (XTEM). Only surface blistering has been observed for He and H sequentially implanted SiO2/Si samples after annealing in temperature range up to 1000 °C. However, as for the He and H implanted Si3N4/Si samples, surface features including blistering and the localized exfoliation of both the top Si3N4 layer and the implanted Si layer have been well demonstrated during subsequent annealing. XTEM observations reveal quite different defect morphologies in two kinds of materials under the same implantation and annealing conditions. The possible mechanisms of surface damage in two kinds of materials have been discussed and presented based on the XTEM results.