Effect of dose and annealing conditions on the structure of silicon-on-insulator material implanted with oxygen at high temperature and at high current density

Abstract

Conventional and high resolution electron microscopy were used to study the structure of silicon-on-insulator material synthesized at higher temperature and higher current density (1 mA cm -2) than are conventionally used. As dose increases from 0.3 to 1.8×10 18 cm -2 the buried xide thickensto 0.3 microm and trails of bubbles from at the surface which increase in size to 14 nm and depth to 0.15 microm. The defect structure in the top Si layer, consisting of multiple stacking faults located only near the buried oxide interface, remains constant with dosage. During the early stages of annealing, the bubbles and the multiply faulted defects are eliminated and large (20–30 nm) precipitates with lateral dislocations form near the buried oxide interface. Increasing the temperature from 1250 to 1350°C, causes precipitates to grow and to incorporate into the oxide layer. The pinned dislocations are eliminated simultaneously with the incorporated precipitates. This results in a defect density of only 10 5 cm -2m which is three to four orders less than material implanted at lower temperatures and medium current density.