Study of tungsten oxidation in O2∕H2∕N2 downstream plasma

Abstract

Articles you may be interested inStudy on the oxidation and reduction of tungsten surface for sub-50nm patterning process J. Vac. Sci. Technol. A 30, 061305 (2012); 10.1116/1.4758790 Effect of Cu contamination on recombination of O atoms on a plasma-oxidized silicon surfaceThe surface oxidation of tungsten is a serious issue in plasma processing of advanced integrated-circuit devices where tungsten is being used as a gate electrode. In this article, we study tungsten oxidation in O 2 / H 2 / N 2 downstream plasma at a temperature ഛ300°C. The results show that oxidation occurs rapidly in O 2 downstream plasma to form stable WO 3 . However, oxidation can be reduced effectively by adding H 2 and totally suppressed when H 2 concentration in the gas feed reaches a certain low level at which the plasma is still oxygen dominant. Tungsten oxidation increases significantly with sample temperature and exposure time in O 2 downstream plasma. However, H 2 addition reduces both temperature and time dependences due to the coexistence and competition of oxidation and reduction processes. When N 2 is also added, the efficiency of H 2 in O 2 downstream plasma in controlling tungsten oxidation is lowered. The findings may provide effective approaches to various applications of selective oxidation over tungsten, such as photoresist stripping and polysilicon oxidation on tungsten gate structures.

Laser heating and detection of bilayer microcantilevers for non-contact thermodynamic measurements

“…3(b)). 13,14,16,17 Tungsten oxidation (WO 3 ) at reduced pressures increases exponentially with a small addition of oxygen in the temperature range of 20 C to 300 C, and rapidly increases above 300 C. 16,17 At higher powers (several mW), the microcantilevers go through Deflection peaks observed at the beginning and end of the laser heating pulse are attributed to ablation backpressure from the heating laser. [12][13][14][15] an irreversible bending transition similar to that observed for gold (Au) coated silicon nitride microcantilevers, and the W film becomes optically transparent or completely ablated.…”

The effect of thermal annealing in a hydrogen atmosphere on tungsten deposited on 6HSiC

“…2. The increase in W peak height after annealing in hydrogen due to the removal of oxygen, has also been observed by other researchers [16], [17]. The RUMP simulation of the sample annealed at 700 ºC indicated that (1), (2) and (3) …”

Oxidized Titanium Tungsten Surface Functionalization by Silane-, Phosphonic Acid-, or Ortho-dihydroxyaryl-Based Organolayers

“…This W 4f 7/2 from the substrate at 31.6 eV will be set as the binding energy reference in the following. The presence of well-defined doublets located at 36.1 and 38.2 eV along with a broad feature at higher binding energy typical of the W 6+ state in oxides is consistent with an oxidized TiW surface. , In Figure b, Ti 2p 3/2 and Ti 2p 1/2 with binding energies of 458.6 and 464.4 eV, respectively, correspond to Ti 4+ state in oxides, whereas two other peaks observed at 453.7 and 459.7 eV correspond to metallic Ti 0 in TiW. , The area ratio of W/Ti corrected by photoionization cross section is 2.4: the TiW substrate contains more W than Ti. In Figure a, O 1s spectra show two peaks located at 530.5 and 531.3 eV, which are identified as contributions from metal oxides (labeled metal–O) and from metal hydroxides (labeled metal–OH), respectively.…”