New analysis methods useful for understanding both complex waveforms and statistical behaviors of Random Telegraph Noise (RTN) are proposed. Complex waveforms are clearly visualized using Time Lag Plots. Bias dependence of statistically extracted average trap number is discussed, with emphasis on the importance of undetectable traps on product reliability.

A new accelerated testing scheme for detecting SRAM bit failure caused by random telegraph noise (RTN) is proposed. By repeatedly monitoring the fail bit count (FBC) under a reduced margin operation condition, increasing trend of FBC along time was clearly observed, which is believed to be caused by RTN. In addition, physics-based ultra-fast Monte Carlo RTN simulation program has been developed, which quantitatively reproduces the test results. By using the simulation calibrated by the test, product reliability against RTN can be accurately predicted.

We report the effects of Al doping on electromigration in damascene Cu interconnects. Al doping was performed by thermal diffusion from a CuAl seed layer positioned underneath the Cu interconnects. To investigate the dependencies of the Al concentration, the seed CuAl layer thickness was increased from $40\text{to}90\mathrm{nm}$ on a planar surface. The effects of Al doping on the incubation time, drift velocity, and critical product of electromigration were investigated. The drift velocity of Cu mass transport in CuAl alloys decreases with an increase in the concentration of Al atoms. The observed critical product of electromigration is $1500\mathrm{A}∕\mathrm{cm}$ , and it is independent of the Al concentration. The measured activation energies of the normalized drift velocities for CuAl seed layer thicknesses of 40, 60, and $90\mathrm{nm}$ are 1.2, 1.4, and $1.5\mathrm{eV}$ , respectively. The Al concentrations at $\mathrm{Cu}∕\mathrm{Si}\mathrm{C}\mathrm{N}$ interface, grain boundary, $\mathrm{Ta}∕\mathrm{Cu}$ interface, and bulk were investigated along the length of a line by the electron microprobe technique. The time dependent Al concentration at the $\mathrm{Cu}∕\mathrm{Si}\mathrm{C}\mathrm{N}$ interface near the cathode end of the line is observed. These characteristics indicate that the doped Al affects the electromigration-induced Cu diffusion and does not affect the driving force.

In this paper, we investigated the effect of impurity (aluminum; Al) doping on the resistivity of damascene copper (Cu) interconnects by categorizing it into surface, grain-boundary, and impurity-scattering factors by means of a comprehensive scattering model. Segregation of Al dopant atoms to the interface of the lines increases the resistivity through increased surface scattering. Electromigration (EM)-induced Cu drift is suppressed as the Al concentration increases. The EM lifetime is improved by the suppression of Cu diffusion due to the piled-up Al at the top surface of the Cu interconnects.