AbstractLow-κ dielectrics have to meet stringent requirements in material properties in order to be successfully integrated. A particularly difficult challenge for material development is to obtain a combination of low dielectric constant with good thermal and mechanical properties. Incorporation of low dielectric constant materials such as porous silica based materials as a replacement to conventional dielectrics like SiO2 and use of Cu metallization schemes has become a necessity as critical dimensions of devices decrease. This paper is focused on the challenges in developing materials with low dielectric constant but strong thermo mechanical properties.
Thin films of Ultra-Low materials such as porous Methyl Silsesquioxane (MSQ) (κ=2.2) were implanted with argon 1 × 1016 cm-2 dose at energies varying from 20 to 50 keV at room temperature. This work shows that the surface hardness of the porous films can be improved five times as compared to the as-deposited porous films by implanting Ar with 1 × 1016 cm-2 doses at 20 keV, sacrificing only a slight increase (∼9%) in dielectric constant (e.g., from
2.2 to 2.4). The hardness persists after 4500C annealing. In this current work, an ion implantation strategy was pursued to create a SiO2-like surface on MSQ. The effects of implantation parameters on the barrier property and bulk stability of MSQ were then studied. The results reveal one possible route to attain the “zero barrier thickness” requirement for interconnects systems.
The roles of hydrophobic group on the surface of ultra low dielectric constant porous silica film during thermal treatment