Abstract
The purpose of the thesis is to find the condition that can lower the dielectric constant of porous SiO2, by changing the reflux temperature and the volume of catalyst NH4OH, to use NH3 plasma treatment as the porous SiO2 film surface modification to enhance the Cu diffusion resistance, and to investigate the effect of NH3 plasma treatment after CMP process on Cu/ porous SiO2 damascene structure. We use FTIR, C-V, and I-V measurements to understand the phenomenon of hydrophobic surface, dielectric constant, and leakage current mechanism. The porous SiO2 film were refluxed at temperature varying from 50℃to 80℃and added catalyst NH4OH changing from 0.2ml to 0.3ml/3ml precursor. The value of the film increase from 2.2 to 3.4. We find the best deposition condition of the porous SiO2 film is 50℃ for the reflux temperature, 0.2ml for the volume of the catalyst NH4OH. Dielectric constant of this film is 2.2. Meanwhile, the NH3 plasma and remote NH3 plasma treatment were applied to modify the surface of deposited PEoxide/porous SiO2,in order to enhance Cu diffusion resistance. From C-V data, this 15min. NH3 plasma treatment can increase the thermal stable temperature of Cu/PEoxide /porous SiO2 up to 450℃. But the damage on the interface was observed in leakage current measurements. But the remote NH3 plasma can reduce this interface damage. Finally, NH3 plasma is a good after CMP cleaning process. It is shown on our leakage current measurements onＣu/porous SiO2 damascene structure. Frenkel –Pool emission was the leakage mechanism in this porous SiO2 film.