The implementation of a reliable router chip

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.Includes bibliographical references (leaves 43-44).by Kin Hong Kan.M.Eng

Charge storage in nanocrystal systems: Role of defects?

Wet thermal oxidations of polycrystalline Si₀.₅₄Ge₀.₄₆ films at 600°C for 30 and 50 min were carried out. A stable mixed oxide was obtained for films that were oxidized for 50 min. For film oxidized for 30 min, however, a mixed oxide with Ge nanocrystallites embedded in the oxide matrix was obtained. A trilayer gate stack structure that consisted of tunnel oxide/oxidized polycrystalline Si₀.₅₄Ge₀.₄₆/rf sputtered SiO₂ layers was fabricated. We found that with a 30 min oxidized middle layer, annealing the structure in N₂ ambient results in the formation of germanium nanocrystals and the annealed structure exhibits memory effect. For a trilayer structure with middle layer oxidized for 50 min, annealing in N₂ showed no nanocrystal formation and also no memory effect. Annealing the structures with 30 or 50 min oxidized middle layer in forming gas ambient resulted in nanocrystals embedded in the oxide matrix but no memory effect. This suggests that the charge storage mechanism for the trilayer structure is closely related to the interfacial traps of the nanocrystals.Singapore-MIT Alliance (SMA

Nanocrystalline Ge Flash Memories: Electrical Characterization and Trap Engineering

Conventional floating gate non-volatile memories (NVMs) present critical issues for device scalability beyond the sub-90 nm node, such as gate length and tunnel oxide thickness reduction. Nanocrystalline germanium (nc-Ge) quantum dot flash memories are fully CMOS compatible technology based on discrete isolated charge storage nodules which have the potential of pushing further the scalability of conventional NVMs. Quantum dot memories offer lower operating voltages as compared to conventional floating-gate (FG) Flash memories due to thinner tunnel dielectrics which allow higher tunneling probabilities. The isolated charge nodules suppress charge loss through lateral paths, thereby achieving a superior charge retention time. Despite the considerable amount of efforts devoted to the study of nanocrystal Flash memories, the charge storage mechanism remains obscure. Interfacial defects of the nanocrystals seem to play a role in charge storage in recent studies, although storage in the nanocrystal conduction band by quantum confinement has been reported earlier. In this work, a single transistor memory structure with threshold voltage shift, Vth, exceeding ~1.5 V corresponding to interface charge trapping in nc-Ge, operating at 0.96 MV/cm, is presented. The trapping effect is eliminated when nc-Ge is synthesized in forming gas thus excluding the possibility of quantum confinement and Coulomb blockade effects. Through discharging kinetics, the model of deep level trap charge storage is confirmed. The trap energy level is dependent on the matrix which confines the nc-Ge.Singapore-MIT Alliance (SMA

An Orthogonal Study of Industrial Scale Colour Fading Process of Cotton Fabric

Colour fading is now a popular process used for imparting a vintage look to textile and fashion products, which enhances market value because of the current fashion trends. This study examined a non-aqueous colour fading process with the use of oxygen plasma-induced ozone treatment. An industrial scale machine and commercially available red sulpur-dyed cotton fabric (with 0.5 %, 1.5 % and 2.5 % colour depths) were used in this study. Since the colour fading process factors are inter-related to each other, a specific experiment approach, i.e. orthogonal method, was used for obtaining the optimum conditions in an industrial scale colour fading process. Three process factors used in the industrial scale colour fading process, i.e. (i) oxygen gas concentration (%); (ii) amount of water in fabric (%); and (iii) treatment time (minutes), would be studied in this paper. Through the orthogonal method, the optimum conditions for colour fading of the three colour depths of cotton fabric dyed by red sulphur dye were determined and their optimum conditions were same. The optimum conditions of the colour fading of the three colour depths were: (i) 70 % oxygen gas concentration; (ii) 35 % amount of water in fabric; and (iii) 30 minutes treatment time. Although colour fading conditions are the same, the order of importance of these process factors was different. Unlike the conventional colour fading process, oxygen plasma-induced ozone colour fading treatment can achieve uniform and even colour fading effect in the cotton fabric effectively

Atmospheric pressure plasma‐induced decolorisation of cotton knitted fabric dyed with reactive dye

The aim of this study was to investigate the decolorisation effect of atmospheric pressure plasma treatment on knitted fabrics dyed with reactive dyes under different processing parameters, ie, air concentration, treatment duration and water content. The fabrics were dyed with reactive dye of a blue colour, and the colour depths were 0.5%, 1.5% and 3.0% on weight of fabric. The colour properties of untreated and plasma‐treated fabric samples were evaluated by means of reflectance, K/S and relative unlevelness index. The colour properties were evaluated instrumentally and quantitatively in order to study the decolorisation effect induced by atmospheric pressure plasma treatment. Experimental results revealed that the desired decolorisation effect was heavily influenced by the atmospheric pressure plasma treatment processing parameters. Although the desired decolorisation effect could be obtained by controlling the processing parameters of the atmospheric pressure plasma treatment, the treatment did not provide any significant reduction in the bursting strength of the fabric

Formation of Nanocrystalline Germanium via Oxidation of Si₀.₅₄Ge₀.₄₆ for Memory Device Applications

In this work, we studied the possibility of synthesizing nanocrystalline germanium (Ge) via dry and wet oxidation of both amorphous and polycrystalline Si₀.₅₄Ge₀.₄₆ films. In dry oxidation, Ge was rejected from the growing SiO₂ forming a Ge-rich polycrystalline layer. As for wet oxidation, Ge was incorporated into the oxide, forming a layer of mixed oxide, SixGe₁âxOy. Formation of nanocrystalline Ge was observed when the layer of SixGe₁âxOy was annealed in a N₂ ambient. We have fabricated a metal-insulator-semiconductor structure with nanocrystalline Ge embedded within the insulator layer to study its feasibility as a memory device.Singapore-MIT Alliance (SMA