Reactively sputtered TiN as a diffusion barrier between Cu and Si

Abstract

Efficiency of TiN diffusion barrier between Al and Si prepared by reactive evaporation and rapid thermal annealingThe properties of lOO-nm-thick Ti ss N 45 and Ti4sN55 films as diffusion barriers between silicon substrates and thin Cu films were studied by sheet resistance measurements, Rutherford backscattering spectrometry, Auger electron spectroscopy, secondary-ion mass spectrometry, transmission electron microscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy, x-ray diffractometry, and diode leakage current measurements. For unpatterned Siltitanium nitride/Cu samples, all the layers were intact and there was no indication of interdiffusion by conventional depth profiling techniques up to 700 ·C for Ti.;sN 45 and 900 ·C for Ti45N55 after 30 s rapid thermal anneal in N 2 , respectively. Leakage current measurements did not show deterioration of diode junction (with junction depth of 0.25 and 0.30 f..lm) up to 650°C for Ti ss N 45 and 800·C for Ti 4s N 55 . The improvement in failure temperature of the Nrich Ti4sN55 diffusion barrier is a result of the lower defect density and a more stable feature furnished by nitrogen stuffed at the defects. ' 5176

Impact of the Unique Physical Properties of Copper in Silicon on Characterization of Copper Diffusion Barriers

“…Some groups have applied such analysis techniques as SEM (scanning electron microscopy) and even optical microscopy to detect the first signs of degradation of barrier integrity by appearance of defects on the surface of the barrier layer or the copper film, or appearance of etch pits after chemical removal of the barrier layer and selective etching of silicon (see, e.g., [5,15,18,20,82,99,100,103]). Plan view and cross-sectional TEM analyses (see, e.g., [11,14,19,21,71,93,96,98,101,104]) were used to detect interaction at the interfaces, degradation of the interface sharpness, and formation of spikes of Cu-silicide at the interface, or to measure Cu or Al concentration at different depths of the barrier layers using EDX (energy-dispersive X-ray spectroscopy) [90,99,105].…”

Copper diffusion into single-crystalline TiN studied by transmission electron microscopy and atom probe tomography

“…Sputter-deposited TiN barrier layers in Cu metallization schemes have been widely studied because of their high thermal (melting point T m = 2930 °C) and structural stability combined with a low electrical resistivity (44-197 µΩ cm) [1,2]; thus meeting all the requirements for application in miniaturized electronic devices.…”

Interfacial design of Cu/SiC composites prepared by powder metallurgy for heat sink applications

“…Ta, W) [5][6][7], nitrides or carbides (e.g. TiN, TaN) [8][9][10] and compounds (e.g. TiW) [11][12][13][14].…”