An investigation of silicon boride surface layer resulting from boron diffusion in silicon

Diffusion of boron into silicon produces a layer of silicon boride just above the diffused region. By using transmission electron microscopy, it is shown that the boride layer has island morphology, which could be result of precipitation/clustering of boron beyond critical concentration. X ray diffraction measurement suggests the layer to be composed of mixed phase consisting of amorphous matrix of silicon boride with some SiB_x crystalline fraction. Fourier transform infrared spectroscopy (FTIR) and secondary ion mass spectrometry (SIMS) measurements provide additional insight into the nature of the surface region.