Deposition Of O-doped SiCOH Films And Investigation Of Properties

In order to address the problems caused by device-dimension continuous shrinking in ultralarge-scale integrated chips, such as signal propagation delay, power consumption, and the cross-link between metal interconnects, porous low-dielectric conatant ( low- k), and ultralow dielectric constant ( ultralow- k , k < 2) materials have received more close attention. In the porous low- k and ultralow-k materials under study, the SiCOH film prepared by plasma-enhanced chemical vapor deposition ( PECVD ) becomes a promising candidate for its excellent performance. To reduce dielectric constant of SiCOH film as low as possible, two methods are developed to prepare low- k SiCOH film. One is to reduce molecular polarization, another is to reduce the film density by introducing pores into film. This paper uses ring-structure organosilicon precursor and dopes O in order to increasing porosity of film.This paper investigates the effect of O-doped on bonding configuration, dielectric property and leakage current of the SiCOH low dielectric constant films deposited by decamethylcyclopentasioxane (D5) electron cyclotron resonance plasma. The results show that the leakage current can be reduced obviously on the premise that dielectric constant k is kept at a lower value by small O-doped amount. For the SiCOH film deposited at O₂ flow of 3 sccm, the dielectric constant k lower as 2.62 and leakage current of 8.2×10^-9 A/cm² can be obtained.The structure and properties of films is investigated after annealing films respectively in vacuum. The dielectric constant k of SiCOH is reduced greatly. Decrease of polar bond Si-OH is the main reason for the decrease of dielectric constant.