DEPTH PROFILE ANALYSIS AND STUDY OF THE ELECTRONIC-PROPERTIES OF SILICON-NITRIDE LAYERS PRODUCED BY ION-IMPLANTATION

Thin surface-near nitride layers (SiNx) were formed by implanting N-15 (+) ions with an energy of 30 keV in [100] silicon under high vacuum c onditions at RT. The stoichiometric N/Si ratio of the Si3N4 compound o f 1.33 in the maximum of the N-15 depth distributions was adjusted usi ng the fluence of 6 x 10(17) at./cm(2). The N-15 depth distributions o f the implanted specimens were measured by the resonant nuclear reacti on N-15(p, alpha gamma)C-12 (E(res) = 429 keV) by varying the energy o f the incident proton ion beam. The implanted specimens were subsequen tly annealed by EB-RTA (electron beam rapid thermal annealing) at 1100 degrees C for 15 s and 30 min to investigate the high thermal stabili ty of the SiNx layers. Furthermore, the etch resistance of the SiNx la yers was tested by applying the HF:HNO3 etch solution on the specimens . The electrical characteristics of the as-implanted and annealed SiNx layers were analysed with I-V measurements. It was observed that the prevailing current conduction mechanism is the Poole-Frenkel emission, as it is found also for silicon nitrides prepared by other technologi es.