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Scanning tunneling spectroscopy in the shell-filling regime was carried out at room temperature to investigate the size dependence of the band gap and single-electron charging energy of single Si quantum dots (QDs). The results are compared with model calculation. A 12-fold multiple staircase structure was observed for a QD of about 4.3 nm diameter, reflecting the degeneracy of the first energy level, as expected from theoretical calculations. The systematic broadening of the tunneling spectroscopy peaks with decreasing dot diameter is attributed to the reduced barrier height for smaller dot sizes and to the splitting of the first energy level.

FinFET integration challenges and solutions are discussed for the 22 nm node and beyond. Fin dimension scaling is presented and the importance of the sidewall image transfer (SIT) technique is addressed. Diamond-shaped epi growth for the raised source-drain (RSD) is proposed to improve parasitic resistance (R para ) degraded by 3-D structure with thin Si-body. The issue of V t -mismatch is discussed for continuous FinFET SRAM cell-size scaling.IEDM09-290 12.1.2

Highly scaled FinFET SRAM cells, of area down to 0.128μm 2 , were fabricated using high-κ dielectric and a single metal gate to demonstrate cell size scalability and to investigate V t variability for the 32 nm node and beyond. A single-sided ion implantation (I/I) scheme was proposed to reduce V t variation of Fin-FETs in a SRAM cell, where resist shadowing is a great issue. In the 0.187μm 2 cell, at V d = 0.6 V, a static noise margin (SNM) of 95 mV was obtained and stable read/write operations were verified from N-curve measurements. σV t of transistors in 0.187μm 2 cells was measured with and without channel doping and the result was summarized in the Pelgrom plot. With the 22 nm node design rule, FinFET SRAM cell layouts were compared against planar-FET SRAM cell layouts. An un-doped FinFET SRAM cell was simulated to have significant advantage in read/write margin over a planar-FET SRAM cell, which would have higher σV t mainly caused by heavy doping into the channel region.

A refined version of a molecular theory of liquid phase vibrational energy relaxation (VER) [S. A. Adelman and R. H. Stote, J. Chem. Phys. 88, 4397, 4415 (1988)] is presented and compared to the isolated binary collision (IBC) model. The theory is based on the Gaussian model for the fluctuating force autocorrelation function of the solute vibrational coordinate. Within the Gaussian model, the VER rate constant may be constructed in terms of solute–solvent site–site potential energy and equilibrium pair correlation functions. In the present refined treatment, crossfrictional contributions to the fluctuating force autocorrelation function are retained and its initial value 〈F̃2〉0 is evaluated from an exact rather than an approximate formula. Applications of the theory are made to model Lennard-Jones systems designed to simulate molecular iodine dissolved in liquid xenon at T=298 K and molecular bromine dissolved in liquid argon at T=295 K and T=1500 K. The refinements, along with an improved polynomial fitting procedure for the solute–solvent pair correlation functions, are found to yield significant changes in both the absolute VER rates and in their isothermal density dependencies. Moreover, it is found for all three solutions that the Gaussian decay time is nearly independent of density from ideal gas to the dense fluid regimes. This condition is sufficient for the emergence of an IBC-like factorization of the VER rate constant kliq(T) into a liquid phase structural contribution proportional to 〈F̃2〉0 and a dynamical contribution which is nearly density independent. The liquid structural contribution is, in general, not well-approximated by a contact collisional assumption but rather depends on a range of solute–solvent interatomic separations. For the Br2/Ar solutions, the rate constant isotherms show a superlinear deviation from the low density extrapolation kliq(T)≂ρ0kgas(T) which is qualitatively similar to that observed for a number of cryogenic and pressurized fluids. For the I2/Xe solution a qualitatively different sublinear rate isotherm is found. This ‘‘nonclassical’’ isotherm is correlated with the nonmonotonic density dependence of the magnitudes of the solute–solvent pair correlation function in the region important for the determination of 〈F̃2〉0 found for the I2/Xe system.

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