AVS 51st International Symposium
    Plasma Science and Technology Monday Sessions
       Session PS-MoP

Paper PS-MoP34
A Zero-order Semi-Empirical Physical Model for Chemically-Enhanced Physical Vapor Deposition (CEPVD) of Ta(C)N}

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: D.N. Ruzic, University of Illinois at Urbana-Champaign
Authors: N. Li, University of Illinois at Urbana-Champaign
D.N. Ruzic, University of Illinois at Urbana-Champaign
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Chemically-enhanced physical vapor deposition (CEPVD) is a new technique having the potentiality to deposit films with physical vapor deposition (PVD) quality and chemical vapor deposition (CVD) step coverage. A Ta target is sputtered in a magnetron system with the metal-organic precursor vapor, TBTDET, in combination with a reactive (N2) gas and a secondary RF plasma. CEPVD film properties have demonstrated wide range of variation with the processing parameters. For instance, by controlling the processing the film resistivity drops dramatically from nearly insulating to about 250 ï-ï?­cm. Therefore a zero-order semi-empirical model is established correlating the processing parameters with the target and film surface coverage by Ta, TaN and organic sites, which predicts the target operation mode, and the film elemental composition. The physical component of the model involves the calculation of the plasma properties, reactive sputtering, transportation and deposition of the three kinds of surface sites. The chemical reactions are represented as elementary gas phase reactions enhanced by electron impact, H reducing and ion bombardment. The rate constants are derived by simulation curve fitting with the AES experimental data. The organic by-products accounting for the detection of carbon on the substrate by AES analysis and poisoning of the target are categorized into non-volatile product (OR1) and volatile product (OR2) in a lump-sum assumption. Simulation results are compared with the experiment data with different RF power, bias voltage, pressure, carrier gas flow rate, TBTDET vapor pressure etc, and the deviation is consistently below 25 %. For example, the simulation shows that at certain working conditions the carbon concentration decreases from 61% to 54% as the substrate voltage changes from 0V to -60V, which corresponds to the AES result that the carbon concentration decreases from 51% to 43%.