RBS, RHEED AND THEED STUDIES OF SIMOX AND SIMNI STRUCTURES FORMED BY ION-BEAM SYNTHESIS

Although the field of ion beam synthesis of buried dielectric layers in silicon received much attention in the 1980s, specific details of the process still remain that need to be clarified and reconsidered in order to utilize the technique to its fullest advantage. This research attempts (i) to outline the implantation conditions that minimize the damage in the silicon surface layer of substrates incorporating buried layers of either SiO2 or Si3N4, and (ii) to explore the possibility of directly creating buried layers of Si3N4. In order to ha ve useful single crystal silicon on the top of the buried layer, it is necessary to conduct implants at elevated substrate temperatures and to employ sample preheating from an external heat source independent of the ion beam. The use of high intensity nitrogen implantation looks like a promising approach which enables the synthesis of continuous layers of stoichiometric Si3N4 in situ. Combined analysis methods including RBS, RHEED and THEED are used to characterize the resulting as-implanted structures.