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In this paper, we investigated the influence of both source gas and deposition temperature in plasma-enhanced chemical vapor deposition (PE-CVD) for a SiO2 passivation layer on the electrical properties and reliability of a bottom-gate In–Ga–Zn–O thin-film transistor (IGZO TFT). Two gas chemistries consisting of SiH4–N2O–N2 and tetraethoxysilane (TEOS)–O2 were utilized as the source gases for the PE-CVD SiO2 deposition, and the deposition temperature (${T}_{D}$) was adjusted from 180 °C to 380 °C. The TFT properties were basically identical for both gas chemistries at ${T}_{D}$ of 180 °C. When ${T}_{D}$ increased to 300 °C or higher, the TFTs with the SiO2 passivation deposited by SiH4–N2O–N2 gas chemistry (SiH4-SiO2) drastically changed from the transistor to the conductor. In contrast, the TFT with TEOS-SiO2 passivation maintained its TFT characteristics even at ${T}_{D}$ of 380 °C, despite the degradation of subthreshold characteristics and a negative shift of turn-on voltage were observed due to an electron injection barrier lowering as ${T}_{D}$ increased to 310 °C or higher. We also revealed that a stacked SiO2 passivation that is deposited at a different ${T}_{D}$ is an effective technique to improve the performance and reliability of the IGZO TFT. [ABSTRACT FROM AUTHOR]

This paper details the study of the mechanism of large-grain polysilicon layer formations using metal-induced lateral crystallization (MILC). A model is proposed to predict the growth rate of MILC under the retardation effect of solid-phase crystallization (SPC) at different annealing conditions The model has between extensively validated by experimental data. This paper will show that the SPC exists as a counter-effect to retard the MILC and degrade the superiority of the polysilicon layer. The model has been used to predict the MILC rate of large-grain polysilicon grown by a pulsed-annealing technique that suppresses the undesirable SPC effect. The model prediction agrees well with the experimental results. [ABSTRACT FROM AUTHOR]

In this paper, we showed that the maximum active P concentration of approximately 2 × 1020 cm-1 exists during solid-phase epitaxial recrystallization (SPER). This maximum active concentration is close to the reported values for other active impurity concentrations during SPER. We introduced the concept of an isolated impurity that has no neighbor impurities with a certain lattice range. Assuming that impurities interact with three or four neighbor impurities, we can explain the activation phenomenon during SPER. According to our model, the isolated P concentration Niso has a maximum value of approximately 2 × 1020 cm-1 at a total impurity concentration of approximately 1021 cm-1 , and it decreases with a further increase in total impurity concentration. Deactivation occurs after the completion of SPER with increasing annealing time, and the active impurity concentration decreases with time but is always higher than the maximum diffusion concentration NDiff max. We also observed that NDiff max is independent of the annealing time despite non-thermal activation in the high-concentration region. We evaluated the dependence Of NDiff max on annealing temperatures. We think that this NDiff max can be regarded as the electrical solid solubility NEsol that the active impurity concentration reaches in thermal equilibrium. We observed the transient enhanced diffusion (TED) after the completion of SPER, and that, the deactivation process continues during and after TED, and the corresponding diffusion coefficient is still much higher than that in thermal equilibrium even after TED has finished, which suggests that the deactivation process releases point defects. [ABSTRACT FROM AUTHOR]