AVS 49th International Symposium
    Vacuum Technology Wednesday Sessions
       Session VT-WeM

Paper VT-WeM5
Organic Contaminants Adsorption Behavior on Silicon Wafer Surface Under Reduced Pressure

Wednesday, November 6, 2002, 9:40 am, Room C-104

Session: Outgassing
Presenter: T. Hayashi, Tohoku University, Japan
Authors: T. Hayashi, Tohoku University, Japan
T. Kawaguchi, Tohoku University, Japan
N. Tanahashi, Tohoku University, Japan
M. Saito, Tokyo Electron Ltd., Japan
K. Suzuki, Tokyo Electron Ltd., Japan
Y. Wakayama, Taisei Corporation, Japan
Y. Shirai, Tohoku University, Japan
T. Ohmi, Tohoku University, Japan
Correspondent: Click to Email
It is known that organic contaminants on silicon wafer surface cause many detrimental effects, such as degradation of gate oxide integrity, yield losses, and so on. To prevent that, closed manufacturing system has been proposed. However, these are considered only for outside of process chamber under atmosphere pressure. And now, the low-pressure processes such as CVD, sputter, dry etching, etc. are routinely used under several hundred mTorr or less. The organic contamination behavior on silicon wafer surface in low-pressure chamber has not been reported yet. In this study, we clarified the organic contamination behavior on silicon wafer surface under reduced pressure. We have researched the following three results; 1) The amount of organic compounds adsorbed onto a silicon wafer stored in a chamber under reduced pressure was much more than that stored under atmosphere pressure. 2) The volatile level released from pure n-Eicosane, typical hydrocarbon contaminant, does not depend on the pressure. 3) The adsorption behavior for the amount of volatile from n-Eicosane adsorbed onto silicon wafer surface coexisted with n-Eicosane in the low-pressure chamber is in accordance with Langmuir model of monolayer adsorption and the amount of adsorption saturated is in inverse proportion to pressure. In conclusion, we clarified that the inner pressure of a chamber become lower, the partial pressure of released organic compounds from chamber components becomes higher, that is, the contact frequency between organic compounds and silicon wafer surface become higher. As a result of that, the much amount of organic compounds is adsorbed onto silicon wafer surface.