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 i n silicon received much attention in the 1980s, specific details of th e process still remain that need to be clarified and reconsidered in o rder 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 o f directly creating buried layers of Si3N4. In order to ha ve useful s ingle crystal silicon on the top of the buried layer, it is necessary to conduct implants at elevated substrate temperatures and to employ s ample preheating from an external heat source independent of the ion b eam. The use of high intensity nitrogen implantation looks like a prom ising approach which enables the synthesis of continuous layers of sto ichiometric Si3N4 in situ. Combined analysis methods including RBS, RH EED and THEED are used to characterize the resulting as-implanted stru ctures.