AVS 53rd International Symposium
    Electronic Materials and Processing Thursday Sessions
       Session EM-ThP

Paper EM-ThP41
Room-Temperature Magnetron-Sputtered High-k Titanium Silicate Thin Films for MIM and MOS Device Applications

Thursday, November 16, 2006, 5:30 pm, Room 3rd Floor Lobby

Session: Electronic Materials and Processing Poster Session
Presenter: D. Brassard, INRS-Énergie, Matériaux et Télécommunications, Canada
Authors: D. Brassard, INRS-Énergie, Matériaux et Télécommunications, Canada
L. Ouellet, DALSA Semiconductor, Canada
M.A. El Khakani, INRS-Énergie, Matériaux et Télécommunications, Canada
Correspondent: Click to Email
There is a tremendous ongoing effort for the development of a high dielectric constant (high-k) material that will replace the traditional SiO@sub x@N@sub y@ insulator in both metal-oxide-semiconductor (MOS) transistors and metal-insulator-metal (MIM) capacitors. In this context, we report on the development of a room-temperature magnetron co-sputtering process for the growth of high-k titanium silicate (Ti@sub x@Si@sub 1-x@O@sub 2@) thin films. Ti@sub x@Si@sub 1-x@O@sub 2@ mixed oxide films constitute a highly promising high-k material candidate because they offer the prospect of achieving the best trade-off between the high-k value of the TiO@sub 2@ phase and the unpaired insulating behavior of SiO@sub 2@. The sputter-deposited Ti@sub x@Si@sub 1-x@O@sub 2@ films were integrated into both MIM and MOS capacitors and their structural and electrical properties systematically investigated as a function of the relevant growth conditions (particularly the substrate bias) and the film composition (i.e., the Ti/Si ratio). It is shown that the application of an optimal bias voltage value (of ~ -15 V), during the film growth, leads to a significant densification of the films which in turn is found to improve drastically their electrical properties. Under the optimal growth conditions, the Ti@sub 0.5@Si@sub 0.5@O@sub 2@ films are shown to exhibit an excellent combination of electrical properties, namely: a k of ~17, a leakage current as low as ~10 nA/cm@super 2@ (at 1 MV/cm), and a breakdown field > 4 MV/cm. Moreover, titanium silicate based MIM capacitors showing both high capacitance density of 10 fF/µm@super 2@ and good capacitance linearity (@alpha@ < 1000 ppm/V@super 2@) were achieved. Finally, despite the inherent presence of a ~2 nm-thick SiO@sub 2@ interfacial layer, Ti@sub x@Si@sub 1-x@O@sub 2@ based MOS capacitors with a relatively low density of defects (D@sub it@ ~2x10@super 11@ eV@super -1@cm@super -2@) were achieved after annealing under forming gas.