Julien Gatineau

Improvement in the leakage current characteristic of metal-insulator-metal capacitor by adopting RuO2 film as bottom electrode

The dielectric constant, equivalent oxide thickness (tox), and leakage current properties of Pt/(Al-doped)TiO2/RuO2 capacitors were examined in comparison with Pt/(Al-doped)TiO2/Ru capacitors. The Al-doped TiO2 and undoped TiO2 films grown on RuO2 showed high dielectric constants of 60 and 102, respectively. The minimum tox of these films were 0.46 nm and 0.56 nm, respectively, while still satisfying the dynamic random access memory leakage current density specification (< 1 × 10−7 Acm−2 at capacitor voltage of 0.8 V). These excellent electrical properties of (Al-doped) TiO2 on RuO2 were attributed to the high work function and the reduced interfacial effect on RuO2.

Plasma-Enhanced Atomic Layer Deposition of Cobalt Using Cyclopentadienyl Isopropyl Acetamidinato-Cobalt as a Precursor

Cobalt plasma-enhanced atomic layer deposition (PE-ALD) using cyclopentadienyl isopropyl acetamidinato-cobalt [Co(CpAMD)] precursor and NH3 plasma was investigated. The PE-ALD Co thin films were produced well on both SiO2 and Si(001) substrates. The deposition characteristics and films properties such as resistivity, chemical bonding states and quantitative impurity level contents were investigated. Especially, Co deposition using this precursor was possible at very low growth temperature as low as 100 °C, which enable the deposition on polymer-based substrate. We demonstrate that this low growth temperature PE-ALD can be applicable to patterning of Co film by lift-off method, which was realized by direct deposition of Co on photoresist patterned substrate.

Plasma-enhanced atomic layer deposition of Co using Co（MeCp）2 precursor

Abstract Cobalt (Co) thermal or plasma enhanced atomic layer deposition (PE-ALD) was investigated using a novel metal organic precursor, Co(MeCp) 2 , and NH 3 or H 2 or their plasma as a reactant. The growth characteristics, electrical and microstructural properties were investigated. Especially, PE-ALD produced Co thin films at low growth temperature down to 100 °C. Interestingly, the low temperature growth of Co films showed the formation of columnar structure at substrate temperature below 300 °C. The growth characteristics and films properties of PE-ALD Co using bis(η-methylcyclopentadienyl) Co(II) (Co(MeCp) 2 ) was compared with those of PE-ALD Co using other Cp based metal organic precursors, bis-cyclopentadienyl cobalt (II) (CoCp 2 ) and cyclopentadienyl isopropyl acetamidinato-cobalt (Co(CpAMD)).

Pulsed-Chemical Vapor Deposition of Ruthenium and Ruthenium Dioxide Thin Films using RuO4 Precursor for the DRAM Capacitor Electrode

Ru and RuO2 thin films were grown on Si, SiO2 and TiN substrates by pulsed chemical vapor deposition using RuO4 and 5%H2/95%N2 as the precursor and reducing gas, respectively. Ru film showed an excellent thermal stability, high growth rate of 0.18nm/pulse (0.43nm/min), low impurity concentration, conformal step coverage and very smooth surface. The TiO2 film grown on this Ru electrode showed much improved electrical performance compared to those on the other Ru electrode. RuO2 thin film can be deposited by decreasing the H2/N2 gas supply rate. RuO2 thin film has excellent conformal step coverage on a hole structure with an opening diameter of 100nm and a depth of 1000nm. With ¬RuO2 thin film as sub-electrode of MIM capacitor, the equivalent oxide thickness of TiO2 film could be decreased to 0.56nm within the specification of DRAM leakage current.

Synthesis and PEALD evaluation of new Nickel precursors

A new family of oxygen and fluorine free Nickel (Ni) precursors, which are based on allyl and alkylpyrrolylimine ligands [Ni(allyl)(PCAI-R)], has been developed and evaluated for a Ni metal film with thermal and plasma enhanced ALD using H₂/NH₃ as a reducing agent. From Ni(allyl)(PCAI-iPr), pure Ni film with very low resistivity (5.3 μO·cm) was obtained at 400°C by PEALD, which is close to the resistivity value of bulk Nickel (5-10 μO·cm) [1].

A New Liquid Precursor for Pure Ruthenium Depositions

With our set-up conditions (substrate temperature: 350°C, precursor temperature: 10°C, bubbling delivery, carrier gas flow rate: 20sccm, bubbler pressure: 20 Torr), we obtained a deposition rate close to 20 A/min, according to EDX analyses (fig.2). From similar experiments at various temperatures, the activation energy of the precursor was found to be 0.44eV on SiO2 substrates. It demonstrates the high volatility and reactivity of this new precursor. We deposited ruthenium films on different kinds of substrates, SiO2 and TaN/Ta. These materials were especially selected as they are representatives of the underlying materials that may be used together with ruthenium in 2 applications, respectively metal gate in CMOS and barrier/seed layer between the low-k and copper layer. As shown in fig. 2, we could not observe any incubation time or delay of formation of ruthenium films, whichever substrate was used. The good adhesion of the ruthenium films on the substrates was checked by scotch tape peeling tests.