No abstract

Flims of metal oxides, such as Ta2O5, Nb2O5, Al2O3, HfO2, ZrO2 and TiO2 have been fabricated by use of different precursor materials, deposition techniques and annealing techniques. Several analytical methods were applied to study the layers. New data of fundamental properties of these metal oxides are reported and related to practical features that are of importance in device design and manufacturing of advanced, highly integrated devices. This overview may facilitate the choice of an optimal combination of precursor material, deposition technique and corresponding annealing procedure for a specific application of these metal oxide films in microelectronics.

We present a procedure whereby a sheet of donor atoms is incorporated in (100) Si during molecular beam epitaxial growth, Analysis by secondary ion mass spectroscopy and transmission electron microscopy shows that the width of such 8-function doping layers is only a few lattice planes. Tunneling spectroscopy and transport measurements give evidence for quantum confinement of the electronic charge in the layer and thus confirm the narrow width.For a number of Si device applications an extremely sharp and high density doping profile is required. In principle such a sharply defined doping layer can be achieved with molecular beam epitaxial (MBE) growth ofSi. The problem is that for Sb or Ga densities in the 10 20 em -3 range there are significant surface segregation and a low rate of incorporation into the growing Si crystal, At the typical growth temperature of -700 °C the dopants are carried along the surface of the growing crystal. The doping profile is significantly broadened. 1To overcome this difficulty two procedures have been reported in the literature. In Ref 2 the co-evaporation of a layer of Si and dopant at room temperature followed by solid phase epitaxy has been employed. Reference 3 introduces secondary ion implantation, whereby a negative potential ( -500 V) is applied to the substrate and the dopant is incorporated by knock-on from Si ions. Doping spikes of _10 19 em

No abstract

No abstract

Films of tantalum pentoxide (Ta2O5) have been fabricated by use of different precursor materials, deposition techniques and annealing procedures. Several analytical methods were appliedto study the layers. Fundamental properties and new data are reportedand related to practical features that are of importance in device design and manufacturing of advanced, highly integrated devices. This overview may facilitate the choice of an optimal combination of precursor, deposition technique and corresponding annealing procedure for aspecific application of these films in microelectronics, since the electrical properties reveal the potential of Ta2O5 films for the use in 64Mbit and 256Mbit DRAM devices as high dielectric constant material.

No abstract

No abstract