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One-compartment hydrogen peroxide fuel cells with Co, Cu, and Fe phthalocyanine (PC) and iron nitride (FexN) as cathodes and Ni anode have been investigated as sustainable energy sources. The cells were operated under acidic conditions and at room temperature. The potentials for onset of the catalytic currents in these cells were determined via cyclic voltammograms. The reduction current onset potentials of FePC, CoPC, CuPC and FexN were 0.56 V, 0.42 V, 0.51 V and 0.57 V, respectively. Potential-current linear sweep voltammetry was utilized to determine the open circuit potentials (OCP) and the power densities the fuel cells. The OCPs for Co, Cu, and Fe phthalocyanines and FexN were 0.47 V, 0.57 V, 0.56 V and 0.58 V, respectively. The maximum output power densities of FePC and CoPC, CuPC, and FexN were 3.41 mW cm−2, 0.39 mW cm−2, 0.39 mW cm−2 and 0.76 mW cm−2, respectively. These power densities are suitable for powering micro-devices.

In this work we have investigated the material properties and electrical performance of polycrystalline silicon films formed by an excimer-laser-anneal (ELA) process in different annealing environments. Particularly, we investigated the ELA process in air, nitrogen, argon, and helium and compared it with the standard ELA process in vacuum. Polysilicon thin-film transistors were fabricated using polysilicon material formed by ELA in different environments. We found that while the performance attributes of polysilicon films annealed in vacuum or inert ambient were quite similar, the performance of polysilicon annealed in air was drastically inferior to all. This result was attributed to the increased oxygen incorporation in the film in the case of the ELA process in air. Oxygen increased the density of both deep states and tail states in the polysilicon bandgap. One mechanism, proposed to account for the deterioration in performance, was the oxygen-induced formation of structural deficiencies in grain boundaries and bulk grain regions and its relation to generation of deep-state and tail-state defects.

A novel design of electrochemical planarization (ECP) system is proposed consisting of a rotating anode, a segmented cathode with very small interelectrode distance, and forced convection. Copper and tantalum anodic polarization curves and steady-state data were collected to validate the electropolishing conditions of the new design. Excellent ECP was produced on patterned electroplated copper films on silicon wafers using this approach.

Lanthanum-containing oxide films are emerging candidates for gate-oxide films, due to expected high dielectric constants as well as promising crystal and electronic band structure. We have used tris(bistrimethylsilylamido)-lanthanum La[N(SiMe 3 ) 2 ] 3 to achieve atomic layer deposition of La 2 O 3 on a (100) Si wafer. Crystalline and electrical properties of the resulting films have been characterized. Dielectric constant values in the range of 20-23, and a dielectric breakdown field of about 4.2 MV/cm were observed. The electrical properties of our structures remain consistent even after prolonged ambient exposure.

Atomic layer deposition of uniform thin hafnium oxide films has been demonstrated directly on H-terminated silicon surfaces using anhydrous hafnium nitrate (Hf(NO 3 ) 4 ) precursor and H 2 O vapor. Atomic layer deposition was initiated on hydrogen terminated silicon surfaces and occurred at substrate temperatures as low as 160°C. X-ray diffraction analysis indicated that as-deposited films were smooth, uniform, and amorphous, and that film morphology can be altered by a post-deposition anneal. X-ray photoelectron spectroscopy analysis indicated that films are oxygen rich, contain silicate, and that residual NO 3 and NO 2 from the precursor can be eliminated by a post-deposition anneal. For a ∼57 A HfO 2 film, a dielectric constant of κ ≅ 10.5 and a capacitive equivalent thickness of ∼21 A were obtained.

Thin stacks comprised of alternating layers of Ta 2 O 5 /HfO 2 , Ta 2 O 5 /ZrO 2 , and ZrO 2 /HfO 2 were investigated as high-permittivity insulators for possible gate dielectric applications These thin layers were deposited on silicon substrates using atomic layer deposition. Nanolaminates with silicon oxide equivalent thickness of about 2 nm had dielectric constants of around ten and leakage current densities at 1 MV/cm of around 10 -8 A/cm 2 . Of the three kinds of nanolaminates investigated. ZrO 2 /HfO 2 structures showed the highest breakdown field and the lowest leakage current.

Deposition of thin and conformal copper films has been examined using atomic layer deposition as possible seed layers for subsequent electrodeposition. For this investigation, the copper films were deposited on glass plates as well as on , , and films on silicon wafers. Typical resistivities of these films ranged from for thick copper films to for thick films. The adhesion of the copper films deposited on and at was excellent. These films were highly conformal over high aspect ratio trenches. ©2000 The Electrochemical Society