Amorphous Si-N films have been synthesized from SiI~ and NI~ by reactive plasma deposition at 275~ in an improved radial flow reactor. With appropriate control of machine and process" variables, films have been made with Si/N ratio of 0.75-1.5, density of 2.8-2.2g cm -~, refractive index of 1.9-2.3, stress of 2 • l0 s dynes cm -2 compressive to 5 • 109 dynes cm -2 tensile, and electrical resistivity at 2 • 106 V/era of I0~~ ~-cm. The process is MOS compatible and it produces relatively thick (1 ~m) crack-resistant Si-N films (at 450~ having excellent step coverage and good adhesion to both Au and A1 metallization. This paper describes the deposition technique, effect
The Hall coefficient of the ternary semiconductor AgSbTe2 near room temperature is positive in some specimens and negative in others, although the Seebeck coefficient is always positive. The negative Hall coefficient decreases as the temperature is lowered from 180°K to 70°K and changes sign in lower temperatures. This negative Hall coefficient is associated with the presence in the AgSbTe2 of a second phase consisting of Ag2Te. The properties of the two-phase material are interpreted in terms of the theory of the transport properties of inhomogeneous semiconductors. In single-phase AgSbTe2 containing 3×1019 holes per cm3, the hole mobility is 35 cm2/v sec at 300°K and it varies approximately as T−0.5. {Note added in proof. It has been suggested by Armstrong, Faust, and Tiller [J. Appl. Phys. 31, 1954 (1960)] that the pattern in Fig. 3(a) is associated with the presence of Sb2Te3 as a Widmanstätten precipitate along {111} planes in the AgSbTe2. This would indicate that none of the material was single phase. Even though the Sb2Te3 in the measured specimens is present in quantities too small to be detected in our x-ray powder photographs, it may have some effect on the measured properties. Therefore, the electrical properties of single-phase AgSbTe2 have yet to be determined.} The lattice thermal conductivity is so low (0.0064 watts/cm°C at 290°K) that the calculated ``phonon mean free path'' is less than the nearest neighbor distance. The thermal conductivity of a specimen rich in AgSbTe2–Ag2Te eutectic is higher than that of either of the components. This excess thermal conductivity is attributed to circulating thermoelectric currents.
Etching of windows in t h e r m a l l y grown silicon dioxide to achieve an app r o x i m a t e l y 45 ~ taper edge profile has been empirically optimized using NH4F/HF compositions and etching bath temperatures. Steeper slopes or much shallower tapers are obtainable by suitable adjustments ot these two experimental parameters. The mechanism b y which tapering occurs may best be described as a controlled separation of the photoresist/oxide interface which relates the lateral etch rate to the bulk etch rate. Depending on etching conditions, each beveled window edge consists of two or three distinct regions which comprise the final shape of the sloping taper. The dissolution reaction in all instances was found to be activation controlled with an apparent activation energy of 9.9 kcal/mole. Curves of etch rates as a function of t e m p e r a t u r e and H F molarity are presented and a quantitative relationship for etch rate in terms of these two p a r a m e t e r s is given. * Electrochemical Society Active Member.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.