SIMOX WAFERS HAVING LOW DISLOCATION DENSITY FORMED WITH A SUBSTOICHIOMETRIC DOSE OF OXYGEN

The threading dislocation density and the structure of SIMOX wafers formed under different implantation conditions have been investigated using Secco etching, cross-sectional transmission electron microscopy and Raman spectroscopy. The breakdown voltage of the buried oxide layer has also been studied. The dislocation density is greatly affected by the dose and the wafer temperature during implantation. The SIMOX wafer implanted at 180 keV with a substoichiometric dose of 0.4 x 10(18) O+ cm-2 at 550-degrees-C and subsequently annealed at 1350-degrees-C has an extremely low dislocation density on the order of 10(2) cm-2. The effect of the wafer temperature on the reduction of the dislocation density is discussed.