STRUCTURAL CHARACTERIZATION OF NITROGEN ION-IMPLANTATION INTO SILICONFOR SENSOR TECHNOLOGY

In this work buried etch-stop layers in silicon are formed by implanta tion of a substoichiometric dose of nitrogen and annealing at temperat ures up to 1150-degrees-C. Transmission electron microscopy, secondary ion mass spectrometry, Raman spectroscopy and Fourier transform infra red spectroscopy are used to study the structure of the implanted mate rial and its evolution with the thermal treatments. Results show that nitrogen is gettered around the implantation peak and that precipitati on in the form of amorphous SiN and sometimes in alpha-Si3N4 occurs. R aman spectra suggest the presence of a remaining stress in the top Si layer, although the presence of a high density of amorphous SiN precip itates also contributes to the observed shifts.