An experimental study of high concentration (1019 –1021 /cm3 shallow diffusion was undertaken using TEM to investigate the nature of these diffusion-related defects. Phosphorous from a wide variety of sources (PBr3, POCl3, etc.) other than ion implantation was used in temperature range from 950°– 1100°C and for times of 15 minutes to 1 hour. Care was taken in surface preparation and material selection to avoid extraneous defects from sources other than the diffusions.
A high concentration of small dislocation loops (1012/ cm2) was present in the top few microns of the wafers. Diffraction contrast on the loops revealed that they are of edge character with Burger's vector b = ½<110>. Identification of the nature of these loops by tilting method [(g·b)·s] and anomalous dark-faced black-white lobes show they are of the interstitial type, i.e. the observed defects place the surrounding matrix in a compressive state.