Composition and Structure of Si3n4 Implanted with Ti AT 900°C

Abstract

ABSTRACTTi+ ions were implanted to high fluences (up to 5 × 1017 /cm2 ) into Si3N4 substrates heated to around 900°C. Composition vs depth profiles were obtained by RBS (in conjunction with RUMP analysis) and microstructures were examined by TEM. At a fluence of 4 × 1017 /cm2, the Si concentration was considerably reduced at the Ti peak depth but enriched near the surface. By 5 × 1017 /cm2, Si was nearly depleted from the implanted layer, leaving a Ti-rich nitride layer merging continuously into Si3N4. TEN detected TiN precipitates up to several pm in diameter, and coherent with Si3N4 crystallites. A Si-Ti-N ternary phase diagram is used to interpret the observed solid state reactions.