Abstract
In this thesis, our study contains two part. The first part is the study of Porous dielectric SiOxNy as the diffusion barrier for Cu metallization by use NH3 plasma treatment on porous SiO2 film. The second part is the study of Ta-Si(~100 Å) metal diffusion barrier property. We use NH3 plasma treatment on porous SiO2(k~2.2) in After Glow Chemical Vapor Deposition (AGCVD). According to reflecting FTIR, we can prove that more Si-N bonding formed in Porous dielectric SiOxNy to enhance the thermal stability. After the best treatment condition, the C-V curve remains thermally stability after annealing at temperature 400℃ for 30mins. It’s dielectric constant is only 3.26, and is conformed to the requirement of ITRS roadmap(Effective K=3.0~3.6). In the study of Ta-Si(~100 Å) diffusion barrier, the Ta-Si nano-cluster thin films with various composition of Ta and Si are fabricated with Ta+1/2Si targets by radio frequency reactive sputtering deposition. According to XRD and TEM picture, as deposited Ta-Si nano-cluster films is amorphous. And HRTEM picture had also shown the nano-cluster structure directly. Their resistivity of the film is decreasing as the temperature rises. These are characteristics of nanoparticles. Ta-Si film with large Si/Ta ratio has higher resistivity and shows better diffusion barrier performance. The resistivity of Ta-Si film with Si/Ta ratio 0.365 is 195μΩ-cm. The C-V curve of MOS capacitor Cu/Ta-Si/SiO2/Si remains thermally stability after annealing at temperature 400℃ for 30mins. It’s thinkness is only ~90Å, and the adhesion of the film with Cu is 378.2 kg/cm2. The Ta-Si thin film is good condidate of diffusion barrier and adhesion layer for ULSI process.