Main page | Journal list | Log-in

S. Saloum, M. Akel, B. Alkhaled

Effect of electron energy probability function on plasma CVD/modification in a 13.56 MHz hollow cathode discharge

Journal of Physics D 42 (2009) 085201

Langmuir probe diagnostics is done on a RF hollow cathode discharge system (13.56 MHz, 200 W) by inserting a single cylindrical probe in the remote region (50 mm away from the primary argon plasma) and at a distance of 10 mm above the substrate holder. The effects of argon gas pressure, the injection of helium in the remote zone and the substrate bias on the measurements of the electron energy probability function (EEPF) and on the plasma parameters (electron density (n(e)), effective electron temperature (T-eff), plasma potential (V-p) and floating potential (V-f)) have been investigated. The EEPFs and plasma parameters obtained have been used to control two remote plasma processes. The first is the remote plasma enhanced chemical vapour deposition (PE-CVD) of thin films, on silicon wafers, from a hexamethyldisiloxane precursor diluted in the remote Ar-He plasma, where the relative thicknesses of the deposited films were investigated by the ex situ Rutherford back-scattering (RBS) technique. The second is the pure argon remote plasma treatment of a polymethylmethacrylate polymer surface, where the reflectance of the modified surface was measured and compared with the untreated one. It is revealed that by varying the gas mixture/pressure and substrate bias, one can engineer the EEPFs to enhance the desired plasma chemical gas phase reactions thus controlling the plasma CVD and plasma surface modification processes. Auxiliary optical emission spectroscopy diagnostics are discussed as well.

Download PDF (609 kB)

Cited Articles

  1. Zajíčková L., Buršíková V., Kučerová Z., Franta D., Dvořák P., Šmíd R., Peřina V., Macková A.,
    Deposition of protective coatings in RF organosilicon discharges,
    Plasma Sources Science and Technology 16 (2007) S123–S132