AVS 52nd International Symposium
    Plasma Science and Technology Monday Sessions
       Session PS-MoP

Paper PS-MoP20
Effects of N@sub 2@ Additive Gas on Etching Characteristics of Silicon Oxide Layers in F@sub 2@/N@sub 2@/Ar Remote Plasmas

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Plasma Science and Technology Poster Session
Presenter: J.Y. Hwang, Sungkyunkwan University, South Korea
Authors: J.Y. Hwang, Sungkyunkwan University, South Korea
D.J. Kim, Sungkyunkwan University, South Korea
N.-E. Lee, Sungkyunkwan University, South Korea
C.Y. Jang, ATTO, Korea
G.H. Bae, ATTO, Korea
Correspondent: Click to Email
In this study, remote plasma etching characteristics of silicon oxide layers were investigated in F@sub 2@/Ar and F@sub 2@/N@sub 2@/Ar plasmas. A toroidal-type remote plasma source was used for the generation of remote plasmas. The effect of additive N@sub 2@ gas on the etch rates of various silicon oxide layers, including PE-oxide (deposited by PECVD using SiH@sub 4@ and N@sub 2@O), O@sub 3@-TEOS oxide (deposited by thermal CVD using ozone and TEOS precursor) and BPSG (borophosphosilicate glass), was investigated by varying the various process parameters, such as the additive gas N@sub 2@ flow rate and the substrate temperature. The species emitted during cleaning were monitored by Fourier transformed infrared spectroscopy (FT-IR) and residual gas analysis (RGA). The etching rate of the silicon oxide layers is increased 20~25% by adding N@sub 2@ gases to the optimized F@sub 2@/Ar chemistry. Under the current experimental conditions, the largest increase in the etch rate of the silicon oxide layers was observed at the flow condition of F@sub 2@:N@sub 2@=2:1. The etch rates of the silicon oxide layers were increased by the factors of 8.7, 8.3, and 35.7 for PE-oxide, O@sub 3@-TEOS oxide, and BPSG, respectively, at the conditions of F@sub 2@(1500 sccm)/N@sub 2@(750 sccm)/Ar (500 sccm) as the substrate temperature increases from 25 to 350°C. The additive N@sub 2@ flow rate and the substrate temperature were found to be the most critical parameters in determining the etch rate of the silicon oxide layers.