Chemical Beam Deposition of Y 2 O 3 Thin Films with An Ecr
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CHEMICAL BEAM DEPOSITION OF Y203 THIN FILMS WITH AN ECR Maurice Massimo*, Walter Varhue**, Edward Adams***, and Stephen Titcomb** *Sinmonds Precision, Vergennes VT "**Dept.of Electrical Eng., Univ. of Vermont, Burlington, VT 05405 ***IBM Corp., Essex Junct., VT.,
ABSTRACT Stoichiometric thin films of Y20 3 have been deposited on Si at substrate temperatures as low as 300 °C by plasma enhanced chemical vapor deposition using an electron cyclotron resonance (ECR) source. The yttrium source was an organo-metallic compound which was sublimated and fed with He carrier gas into the reactor chamber. Good capacitance-voltage characteristic curves were obtained for the dielectric film and a relative electrical permittivity of 9.9 was measured. This technique is a useful means of depositing oxide ceramic films at low substrate temperatures.
INTRODUCTION There is need of a low temperature technique for depositing single and multi-component oxide ceramic films.[1] The low temperature requirement is imposed by the desire to make the process compatible with integrated circuit fabrication technologies. Materials of present interest include high temperature superconductors such as YBa 2Cu3OT7 x,piezoelectrics such as lead zirconium titinate (PZT) and magneto-optics such as yttrium iron garnet (YIG). The anneal temperature required to obtain the correct oxidation state in these materials is high, in excess of 800 °C. An alternative process would be to co-deposit the metal components in the presence of an oxygen discharge which would substitute energetic ion bombardment for the required thermal energy.[2,3,4] A practical means of obtaining a oxygen ion source in which current density and ion energy can be controlled and scaled for manufacturing applications is an electron cyclotron resonance (ECR) plasma stream source. The ECR plasma stream source operates at low reactor pressures, 1.0 X 10-5 to 1.0 X 10-3 Torr. At these low pressures, the mean free path lengths of the reactant molecules are on the order of the chamber dimensions or at least the distance between the gas inlet and the substrate. This fact reduces the possibility of gas phase reactions which could complicate the process chemistry with multiple reaction pathways. Processes operating in this pressure regime are referred to as chemical beam deposition.[6] An additional advantage of low operating pressures and long mean free path lengths is that the production rate of reactive species can be decoupled from the energetic ion bombardment of the substrate. This is not possible with conventional plasma techniques. With ECR techniques the production rate of reactive species can be controlled by the microwave power level supplied to the resonance chamber. The ion energy strilcing the substrate on the otherhand can be controlled by the application of RF power to the substrate or the divergence of the magnetic field.
Mat. Res. Soc. Symp. Proc. Vol. 249. @1992 Materials Research Society
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The metal components could be introduced via sputtering from multiple targets or by e
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