Low-frequency noise characterization of n- and p-MOSFET's withultrathin oxynitride gate films

MOSFET's with ultrathin (5 to 8.5 nm) silicon oxynitride gate film prepared by low-pressure rapid thermal chemical vapor deposition (RTCVD) using SiH₄, N₂O and NH₃ gases, are studied by low-frequency noise measurements (1 Hz up to 5 kHz). The analysis takes into account the correlated mobility fluctuations induced by those of the interfacial oxide charge. The nitrogen concentration, determined from SIMS analysis, varies from 0 to 11% atomic percentage. A comparison of the electrical properties between thermal and silicon oxynitride films is presented. The increasing LF noise signal with nitrogen atomic percentage indicates the presence of a higher density of slow interface traps with increasing nitrogen incorporation. Besides, a higher Coulomb scattering rate due to the nitridation induced interface charge explains reasonably well the degradation of the low field mobility after nitridation     

Analysis of the trapping characteristics of silicon dioxide after Fowler-Nordheim degradation

An analysis of the trapping characteristics of silicon dioxide (SiO₂) subjected to Fowler-Nordheim degradation is presented. Based on the Fowler-Nordheim threshold and flat-band voltage shifts, the total charge trapped in the oxide (Q_ox) and the centroid ( ) of the trapped charge distribution is extracted while taking into account the charge stored in the fast Si-SiO₂ interface states as a function of the Fowler-Nordheim injection dose. Using qausi-first-order kinetic equations the capture cross sections (σ_i) and densities (N_tⁱ) of the oxide bulk traps are also determined.     

Caractérisation électrique des composants MOS

We present a set of practical manipulations for MOS component characterisation, which is included in a cycle of practical teaching of microelectronics technology. Hardware include a computer controling impedance analyser and a picoamperemeter. The software we present enable the complete characterization of a technological chip which has been specially conceived for educational purpose. The parameter extraction procedure includes : exhaustive analysis of C-V curves (high frequency and quasi static), doping profile obtained from C-V analysis, Zerbst analysis, and analysis of I_d(V_g,V_d) characteristics ofMOS transistors, with extraction of the following parameters : threshold voltage, mobility and mobility reduction factor, sub-threshold swing, series resistance, electrical length and width.     

SOI built-in heat spreader with temperature and pressure integrated sensors for cooling optimization and in situ monitoring

This contribution presents an original solution for sensor integration into a heat spreader which is directly micromachined into the silicon substrate of the device to be cooled. Having both a high thermal conductivity coefficient and a high level of miniaturization, the vapor chamber heat spreader provides a high robustness due to the absence of any moving pumping parts. Simulation results as well as experimental results obtained with a prototype of the heat spreader with integrated temperature and pressure microsensors are presented. The results concerning device cooling optimization using the integrated sensors are highlighting the interest of this approach for accurate in situ monitoring and cooling optimization of silicon-integrated heat spreaders.     

Mobility behaviour of n-channel and p-channel MOSFETs withoxynitride gate dielectrics formed by low-pressure rapid thermalchemical vapor deposition

The electric field dependence of electron and hole mobility was investigated in n-channel and p-channel metal-oxide-semiconductor field-effect transistors with oxynitride gate dielectrics formed using low-pressure rapid thermal chemical vapor deposition with SiH₄, N₂O and NH₃ as the reactive gases. The peak electron mobility was observed to decrease with increasing nitrogen and hydrogen concentration whereas the high-field mobility degradation was improved. The hole mobility was observed to decrease for all electric fields. A self-consistent physical explanation for the observed electron and hole mobility behaviour is suggested based on the electrical results. We attribute the observed mobility characteristics mainly to the trapping behaviour of these films