Reduction of dislocations in a SIMOX film by controlling the annealing sequence

The authors investigated the annealing condition which controlled the generation rate of excess silicon interstitials (Si_int.) and succeeded in reducing the dislocation density by more than 2 orders of magnitude on a SIMOX (separation by implanted oxygen) sample implanted with relatively high dose oxygen at one time under ordinary conditions. An XTEM micrograph of the reference SIMOX sample in this study is presented, and the mechanism of the threading dislocations in SIMOX film during high temperature annealing is shown. It is pointed out that in order to suppress the formation of the threading dislocations, it is important to control the excess Si_int. generated with the formation of SiO₂. Taking into account the results obtained, a new annealing sequence consisting of three major steps has been developed, and is described