Ti/Ni(80%)Cr(20%) Thin-Film Resistor With a Nearly Zero Temperature Coefficient of Resistance for Integration in a Standard CMOS Process
A thin-film resistor out of Ni(80%)Cr(20%) for integration in a standard complementary metal-oxide-semiconductor process with a temperature coefficient of resistance (TCR) below 10 ppm/K was realized by applying a thin Ti layer underneath. The Ti-layer thickness and the temperature and duration of furnace annealing after deposition were optimized in different experiments. The combination of 5-nm Ti + 10-nm NiCr and a 30-min heat treatment at 350degC in a forming gas ambient was found to yield a sheet resistance of about 140 Omega/sq and a TCR of below 10 ppm/K. The long-term drift of the sheet resistance after 1000 h at 200degC was about 0.3%. A transmission electron microscopy analysis was conducted to investigate the structure of the film and a possible change during annealing. An Auger analysis was conducted for film surface analysis.
Fabrication and characterization of precise integrated titanium nitride thin film resistors for 2.5D interposer
Thin film resistors (TFRs) have been fabricated by an optimized process. Titanium nitride (TiN) was used as the resistor layer and was deposited by metal organic chemical vapor deposition MOCVD) process. H2-N2 plasma was applied after every cycle of TiN deposition to stabilize TiN films. The fabrication effects such as deposition of the isolation layer, and passivation layer as well as formation of contact holes on the TiN resistor layer have been investigated. The optimized process allowed the fabrication of stable and precise 25 nm and 35 nm thick TiN resistors with varying line widths and lengths. Electrical characteristics such as resistance, temperature coefficient of resistance (TCR), and isolation layer (SiO2) breakdown voltage were determined. TCR of TFRs decreased with the decrease in the resistor film thickness. Measured resistance values of all fabricated resistors approximated theoretical values within limits of ± 4 %. Resistance was measured at room temperature before and after thermal storage of the resistors at 250 °C and showed no significant change in value.
The distribution of 54-Mn in the enamel and dentine of the rat incisor.
Abstract The distribution of 54 Mn was studied in the lower incisors of rats. Autoradiograms show 54 Mn to be present in the enamel and dentine 5, 10 and 15 days after its administration. In the dentine, the radioisotope is first localized in a zone near to and encircling the pulp and later becomes more diffuse. Pre-existing as well as the newly formed enamel incorporates the isotope. In both enamel and dentine 54 Mn appears to be principally associated with the inorganic portion.