Study of the chemical and structural organization of SIPOS films at the nanometer scale by TEM–EELS and XPS

Two films of semi-insulating polycrystalline silicon (SIPOS) have been prepared by low pressure chemical vapor deposition (LPCVD). Their physico-chemical properties are studied at the nanometer scale with transmission electron microscopy (TEM)–electron energy loss spectroscopy (EELS) and X-ray photoelectron spectroscopy (XPS) techniques by taking into account two main input parameters: the oxygen content and the condition of post-deposition anneal. The compositions of the films are SiO0.17 and SiO0.48. They are made of nanocrystalline silicon embedded in a SiOx matrix with different oxidation states of the silicon atoms. The less the films are oxygenated or the more the films are heat-treated, the more the fraction of crystallized silicon. This study provided a strong baseline to set up a process of fabrication for applications such as high voltage transistors.