Infrared interface analysis of high-k dielectrics deposited by atomic layer chemical vapour deposition

The initial growth mechanism of high-k layers deposited by atomic layer chemical vapor deposition (ALCVD) on differently prepared silicon surfaces and the interface structure, and its evolution, are studied using attenuated total reflection Fourier transformed infrared spectroscopy (ATR-FTIR) in a very interface-sensitive set-up. The ATR-FTIR technique is shown to be an interesting method to study the structure and the interface issues of high k dielectrics deposited on different types of silicon substrates. It is shown that aluminium oxide and zirconium oxide do not have the same dependence on the surface on which they are grown by ALCVD. Whereas the starting surface has only little effect on the structure of the aluminium oxide layer, ZrO/sub 2/ shows big differences. ZrO/sub 2/ has initially a very poor structure when it is grown directly on silicon. The ATR measurements suggest a layer amorphous fraction dependence on the type of oxide on which it is deposited. For aluminium oxide, the differences are only related to the incubation period, whereas the peak shape, i.e. the bonding configuration is not changed.