Investigation On ECR Plasma Deposition And Dielectric Property Of SiCOH Low-k Films

The rapid development of microelectronic devices will lead to the continuous improvement of device performance and the increase of device integrated on a chip. The line size below 45 nm will be achieved and the nano-electronic device will occur by 2010. In order to reduce the RC sign delay, dissipation and cross-link between metal interconnects caused by size shrinking continuously, the porous low dielectric constant (low-k) and ultra-low dielectric constant (uItralow-k, k < 2) material recently received more close attention.From 2003, we use decamethylcyclopentasiloxane (DMCPS) electron cyclotron resonance (ECR) plasma to prepare pore-based SiCOH low-k films. Then we develop a new method combined weak polarization bonds with pores to prepare SiCOH low-k films by incorporating CHF₃ or CH₄ in porous SiCOH films. In the thesis, the films bonding configurations, the effect of structures on dielectric property, and the relationship between films structure and discharge plasma behavior are analyzed. The details are as follows.1. The SiCOH low-k films with k = 2.45 and good thermal stability have been prepared by DMCPS ECR plasma and CHF, or CH, doped. By analyzing the effect of field distribution and source gases flow on films structures and dielectric property, the method to reduce dielectric constant is presented.2. For the pore-based SiCOH films, the porosity can be increased by optimizing discharge condition to preserve the ring structure in the films and further form the cage in the films by linking rings each other. This becomes an available method to reduce dielectric constant. We found that the SiCOH films prepared only by DMCPS show two types of typical bonding configurations, including with and free of Si-0 groups in the films. Due to the strong polarization of Si-OH group, it leads to the increase of k value of the SiCOH films. At the case of high ionization degree of precursor, more Si-OH...