The Hall resistivity H and magnetoresistance of La 1Ϫx Ca x MnO 3 (T c ϭ265 K͒ have been measured at temperatures to 360 K in fields H to 14 T. By comparing H with the magnetization M , we have extracted the anomalous coefficient R s . We uncover an interesting relationship: R s is proportional to the zero-field resistivity from 200 to 360 K. Above T c , the Hall angle tan H ϳM . Further, the effective Hall mobility is H independent over a wide range of H. We contrast these scaling relations with the Hall effect in typical ferromagnets. ͓S0163-1829͑98͒01618-X͔

A finely focused electron beam is used as a source of energy to decompose molecules, e.g., organometallics or hydrocarbons, adsorbed on the surface of a substrate. Films deposited by these means can be used as etch mask for reactive ion etching, as an absorber for various types of radiation, or directly as part of a device structure. A vector scan electron beam system with a LaB6 cathode has been equipped with a temperature controlled reservoir to supply vapors into a differentially pumped sample chamber. The substrate is mounted on a stage which can be cooled or heated in the range of −40 to +110 °C. The ability to utilize backscattered electron micro- scopy is maintained. Area, line, and spot deposition rates have been measured for tungsten hexacarbonyl [W(CO)6] and dimethyl–gold–trifluoro–acetylacetonate [Me2Au(tfac)] at various fluxes, sample temperatures, and current densities. Three-dimensional buildup of tips and free standing lines across holes in membranes and resolution better than 0.25 μm have been achieved. The composition of the deposited films has been analyzed and each deposit is rich in metal and carbon. Tungsten rich deposits can be used as a highly selective etch mask for oxygen plasmas. Effects limiting the ultimate resolution, such as backscattering from the substrate, and scattering from the deposited material are discussed.

We have studied the chemical vapor deposition of copper from 1,5-cyclooctadiene Cu(I) hexafluoroacetylacetonate, a moderately volatile yellow cystalline solid. It yields pure copper by pyrolytic decomposition at 150–250 °C, produces copper films with near bulk resistivity, and has the advantage of being air stable at room temperature.

No abstract

In the microelectronics industry, integrated circuit (IC) device performance is continually increasing while the critical feature sizes are rapidly decreasing. Since this trend is expected to continue for future generations of ICs, areal density constraints often require that circuit designs utilize multilevel structures with vertical interconnects. It was recently demonstrated that the resistivity of the metal interconnects may limit device performance in multilevel thin-film structures. Although Al metallurgy (Al/2 wt.% Cu alloy) is extensively used for IC metallization today, lower resistivity metals, such as gold, copper, and silver may be necessary for designs requiring feature sizes of 0.25 μm or less. Chemical vapor deposition (CVD) is an attractive technique for the conformal filling of submicron vertical interconnects. For CVD to be generally applicable to IC fabrication, volatile precursors with adequate stability must be designed and optimized. Lastly, IC metallization typically requires that both uniformity and conformality be achieved simultaneously in a single process step.