We characterise the performance of a surfaceelectrode ion "chip" trap fabricated using established semiconductor integrated circuit and micro-electro-mechanicalsystem (MEMS) microfabrication processes, which are in principle scalable to much larger ion trap arrays, as proposed for implementing ion trap quantum information processing. We measure rf ion micromotion parallel and perpendicular to the plane of the trap electrodes, and find that on-package capacitors reduce this to 10 nm in amplitude. We also measure ion trapping lifetime, charging effects due to laser light incident on the trap electrodes, and the heating rate for a single trapped ion. The performance of this trap is found to be comparable with others of the same size scale.

SiO2/Si(100) interfaces have been prepared by a low-temperature, 200–300 °C, remote plasma-assisted oxidation-deposition process. The oxidation: (i) creates ∼0.5 nm of SiO2; (ii) removes residual C from an otherwise H-terminated Si surface; and (iii) produces a SiO2/Si interface with a midgap trap density of ∼1×1010 cm−2 eV−1, and when combined with remote plasma-enhanced chemical vapor deposition (RPECVD) of SiO2, (iv) forms a SiO2/Si structure with properties comparable to those prepared by thermal oxidation of Si at 850–1050 °C.

Charge transport in Si-rich silicon nitride thin films is investigated. Over a composition range from Si3N4 to SiN0.54 the field dependent current density is observed to increase by as much as seven orders of magnitude, the residual Si–N bond strain decreases from 0.006 to −0.0026 and the Poole–Frenkel barrier height, ΦB, decreases from 1.08 to 0.55 eV. A direct correlation between ΦB and the local atomic strain is observed. It is concluded that reductions in ΦB are a manifestation of compositionally induced strain relief at the molecular level. Reductions in ΦB result in increased Poole–Frenkel emission rates and consequently higher conductivities in Si-rich films.

Si-rich silicon nitride thin films have been deposited by low pressure chemical vapor deposition, at 850 °C from mixtures of dichlorosilane and ammonia. The films’ elastic properties have been studied as a function of film composition. Fourier transform infrared spectroscopy and ellipsometric data indicate that the local atomic strain is a strong function of the calculated volume fraction of Si contained in the films. A relationship is observed that shows the strain to be inversely proportional to the cube root of the Si volume fraction. A model that accounts for distortion in Si–SixN4−x tetrahedra (x=0–4), upon substitution of silicon for nitrogen in the film is applied to the data. The model is shown to be consistent with measurements of intrinsic film stress across a compositional range from stoichiometric silicon nitride, Si3N4, to nitrogen-free amorphous silicon, a-Si.

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