AVS 47th International Symposium
    Electronics Tuesday Sessions
       Session EL-TuP

Paper EL-TuP15
The Interface Formation of Ta and Low-k Plasma-polymerized Para-xylene (PPpX) and Cyclohexane (PPCHex) and the Diffusion Properties

Tuesday, October 3, 2000, 5:30 pm, Room Exhibit Hall C & D

Session: Poster Session
Presenter: K.J. Kim, Sungkyunkwan University, South Korea
Authors: K.J. Kim, Sungkyunkwan University, South Korea
K.S. Kim, Sungkyunkwan University, South Korea
Y.C. Jang, Sungkyunkwan University, South Korea
G.Y. Yeom, Sungkyunkwan University, South Korea
N.-E. Lee, Sungkyunkwan University, South Korea
Y.C. Quan, Sungkyunkwan University, South Korea
J. Choi, Sungkyunkwan University, South Korea
C.Y. Park, Sungkyunkwan University, South Korea
D.-Y. Jung, Sungkyunkwan University, South Korea
Correspondent: Click to Email
In order to decrease the RC delay of integrated circuit, there have been extensive research activities on Cu interconnect technology utilizing low dielectric constant (low-k) interlayer dielectric materials and Cu to replace the conventional Al metallization scheme. One of the candidates for low-k dielectrics is the organic thin films prepared by various methods. Particularly, low-k plasma-polymerized organic films containing no F which causes various corrosion problems are very promising. However, they do not provide a good interfacial adhesion to metals due to the absence of bonding states between metals and plasma-polymerized low-k organic films. In this study, we investigated the interface formation and diffusion properties between Ta and low-k plasma-polymerized para-xylene (PPpX) and cyclohexane (PPCHex) thin films as a function of O@sub 2@ or N@sub 2@ plasma-treatment conditions using XPS and RBS. Low-k plasma-polymerized thin films were prepared on silicon substrates by PECVD using the para-xylene and cyclohexane precursors at the substrate temperature of 45°C. PPpX and PPCHex were shown to have the dielectric constant as low as 2.70 and thermal stability up to 450°C. Plasma-treatments were performed by MEICP at the inductive power of 400W by keeping the O@sub 2@ and N@sub 2@ flow at 10sccm, respectively. Ta with the film thickness of 40Å was deposited using an electron-beam evaporator at room temperature. These samples were annealed at 450 ~ 500°C in vacuum in order to investigate the interface formation and diffusion of Ta into low-k films. We found that the Ta-C, due to newly created additional functional group, was formed between Ta layer and plasma-treated low-k films, judged from XPS measurements. The diffusion of Ta into the PPpX and PPHex was negligible in the detection limit of RBS.