Porous SiCOH films are of great interest in semiconductor fabrication due to their low-dielectric constant properties. Post-deposition treatments using ultraviolet (UV) light on organosilicate thin films are required to decompose labile pore generators (porogens) and to ensure optimum network formation to improve the electrical and mechanical properties of low-k dielectrics. The goal of this work is to choose the best vacuum-ultraviolet photon energy in conjunction with vacuum ultraviolet (VUV) photons without the need for heating the dielectric to identify those wavelengths that will have the most beneficial effect on improving the dielectric properties and minimizing damage. VUV irradiation between 8.3 and 8.9 eV was found to increase the hardness and elastic modulus of low-k dielectrics at room temperature. Combined with UV exposures of 6.2 eV, it was found that this "UV/VUV curing" process is improved compared with current UV curing. We show that UV/VUV curing can overcome drawbacks of UV curing and improve the properties of dielectrics more efficiently without the need for high-temperature heating of the dielectric.

Neutron irradiation at low fluence decreases the Pb-type and E 0 defect levels in ultra-thin hafnium dioxide films because electrons can fill existing states. These electrons come from electron-hole pairs generated by neutron interactions with silicon and oxygen. Thus, a low fluence of neutrons "anneals" the sample. However, when neutron fluence increases, more neutrons collide with oxygen atoms and cause them to leave the lattice or to transmute into different atoms. This causes the E 0 states to increase. As defect-state concentrations increase, leakage currents increase, but since the E 0 is much lower than the Pb concentration, this is not a dominant factor.

More and more high- and low-k dielectrics are used in microfabrication today. However, as is well known, these materials are easily damaged during processing or during operation in a device. Sources of damage include plasma and/or VUV exposure, water uptake, free radicals as well as cosmic rays. A description of the damage effects on dielectrics from water uptake, plasma and/or VUV exposure, and neutron exposure is presented. Although the results for neutron exposure are presented for a high-k dielectric, HfO2, they can easily be extended to low-k dielectrics.