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An approach is proposed to project thermal behavior in a semiconductor integrated-circuit structure onto a functional space based on the proper orthogonal decomposition (POD). The approach substantially reduces the numerical degrees of freedom (DOF) needed for thermal simulations and requires no assumptions about physical geometry, dimensions, or heat flow paths. The POD approach is applied to a multi-fin FinFET structure having heat sources driven by power pulse excitations with time shifts, width variations, and amplitude modulations. The POD models were compared with detailed numerical simulations (DNS) and it was shown that the POD approach provides thermal solutions that were as accurate and detailed as the DNS. It offers a reduction in numerical DOFs by nearly six orders of magnitude to capture the peak temperatures in multi-fin FinFETs. [ABSTRACT FROM AUTHOR]

We perform a comparative study of various macroscopic transport models against multisubband Monte Carlo (MC) device simulations for decananometer MOSFETs in an ultra-thin body double-gate realization. The transport parameters of the macroscopic models are taken from homogeneous subband MC simulations, thereby implicitly taking surface roughness and quantization effects into account. Our results demonstrate that the drift-diffusion (DD) model predicts accurate drain currents down to channel lengths of about 40 nm but fails to predict the transit frequency below 80 nm. The energy-transport (ET) model, on the other hand, gives good drain currents and transit frequencies down to 80 nm, whereas below 80 nm, the error rapidly increases. The six moments model follows the results of MC simulations down to 30 nm and outperforms the DD and the ET models. [ABSTRACT FROM AUTHOR]

The thermoelastic strains are induced by through silicon vias due to the difference of thermal expansion coefficients between the copper (\sim\!\!\18\ \ppm/^\circ \C) and silicon (\sim\!\!\2.8\ \ppm/^\circ \C) when the structures are exposed to a thermal ramp in the process flow. A compact analytic model (Bessel function) of the strain field is obtained using Kane–Mindlin theory, and has a good agreement with the finite-element simulations. The elastic strains in the silicon in the radial direction and angular direction are tensile and compressive, respectively. The linear superposition of the analytic model of a single via can be used in the multi-via configuration. Due to the interaction of vias, the slightly larger errors of strain occur between the two close vias when the linear superposition is used. [ABSTRACT FROM AUTHOR]

An extensive experimental and theoretical analysis of bipolar differential pairs subject to radical electrothermal feedback is presented. Measurements demonstrate that considerable thermally-induced degradation of circuit characteristics may occur, eventually turning into the full disappearance of a linear region, which is replaced by a hysteresis behavior under voltage-controlled conditions. An analytical model is derived for a simple yet reliable prediction of the distortion of I– V curves. A more elaborated circuit approach is employed to accurately quantify the concurrent destabilizing action of electrothermal and impact ionization effects, as well as to evaluate the impact of layout asymmetries and examine the beneficial influence of emitter degeneration resistors. Simulation results are found to compare favorably with experiments performed on silicon-on-glass test structures with various layouts and isolation schemes, from which the benefits of thermally coupling the two devices become evident. [ABSTRACT FROM AUTHOR]

Various metal carbides (TaC, HfC, WC, and VC) were thoroughly investigated for metal gate CMOS devices with band-edge work functions (WFs). It is found that TaC and HfC are more suitable for the CMOS device application among the various metal carbides. HfC is demonstrated to be a good candidate for NMOS because of its low WF and excellent thermal stability, while TaC + Al shows a high WF and good thermal stability suitable for PMOS device application. In addition, HfC and TaC have a wide range of WF tunability using thin LaN and AIN interlayer or introduction of La and Al into the metal carbides. [ABSTRACT FROM AUTHOR]