ABSTRACT
Microanalysis on doped and undoped silicon thin films deposited by means of Hot Wire Chemical Vapour Deposition (HWCVD) was done in the transmission electron microscope (TEM) in combination with an electron energy loss spectrometer (EELS) and energy selected imaging (ESI). Electrical properties were elucidated on a microscopic level by Scanning Kelvin Probe Microscopy (SKPM). The films were composed of crystalline needles, typically 30 nm in diameter and more than 100 nm long surrounded by a noncrystalline phase. Chemical impurities were locally analysed within the grains and inside the noncrystalline matrix. Inside the grains the concentration of oxygen related defects was found to be much lower than in the noncrystalline matrix. Despite low deposition temperatures of about 190°C diffusion of impurities was observed arising from the substrate and at the interfaces of differently doped layers. With help of SKPM potential and electrical field distributions within the differently doped layer structures could be measured with an appropriate resolution for the microcrystalline structures.
