Infrared and optical emission spectroscopy study of the surface chemistry in atmospheric-pressure plasma-enhanced spatial ALD of Al2O3

Atmospheric-pressure plasma-enhanced spatial atomic layer deposition (PE-s-ALD) is an emerging high-throughput technique used to deposit thin films at low temperatures on large-area substrates. The spatial separation of the ALD half-reactions and the use of an atmospheric-pressure plasma in the co-reactant step give rise to a complex surface chemistry which to date is not well understood. In this study, we employed gas-phase infrared spectroscopy and optical emission spectroscopy (OES) to unravel the underlying chemistry of the PE-s-ALD process for Al2O3 films grown at 80 °C using Al(CH3)3 as the precursor and Ar-O2 plasma as the co-reactant. We identified the reaction products generated at various exposure times of the substrate to the precursor. Infrared absorbance spectra show CO, CO2, H2O and CH4 as the main reaction by-products formed from a) combustion-like reactions of the methylated substrate surface with oxygen radicals and O3 species, and b) H2O molecules either residual or formed in the process that give rise to a concurrent latent thermal ALD component. In addition, CH2O and CH3OH were identified as reaction by-products formed either at the substrate surface or in the plasma. The OES spectra confirmed the combustive nature of the PE-s-ALD reactions as shown by the OH and CH emission peaks that appeared during the spatial ALD process while excited O-species are being consumed

Atmospheric pressure plasma enhanced spatial ALD of ZrO\u3csub\u3e2\u3c/sub\u3e for low-temperature, large-area applications

\u3cp\u3eHigh permittivity (high-k) materials have received considerable attention as alternatives to SiO\u3csub\u3e2\u3c/sub\u3e for CMOS and low-power flexible electronics applications. In this study, we have grown high-quality ZrO\u3csub\u3e2\u3c/sub\u3e by using atmospheric-pressure plasma-enhanced spatial ALD (PE-sALD), which, compared to temporal ALD, offers higher effective deposition rates and uses atmospheric-pressure plasma to activate surface reactions at lower temperatures. We used tetrakis(ethylmethylamino)zirconium (TEMAZ) as precursor and O\u3csub\u3e2\u3c/sub\u3e plasma as co-reactant at temperatures between 150 and 250\u3csup\u3e◦\u3c/sup\u3eC. Deposition rates as high as 0.17 nm/cycle were achieved with N- and C- contents as low as 0.4% and 1.5%, respectively. Growth rate, film crystallinity and impurity contents in the films were found to improve with increasing deposition temperature. The measured relative permittivity lying between 18 and 28 with leakage currents in the order of 5 × 10−\u3csup\u3e8\u3c/sup\u3e A/cm\u3csup\u3e2\u3c/sup\u3e demonstrates that atmospheric PE-sALD is a powerful technique to deposit ultrathin, high-quality dielectrics for low-temperature, large-scale microelectronic applications.\u3c/p\u3

Fam83F induces p53 stabilisation and promotes its activity

p53 is one of the most important tumour suppressor proteins currently known. It is activated in response to DNA damage and this activation leads to proliferation arrest and cell death. The abundance and activity of p53 are tightly controlled and reductions in p53's activity can contribute to the development of cancer. Here, we show that Fam83F increases p53 protein levels by protein stabilisation. Fam83F interacts with p53 and decreases its ubiquitination and degradation. Fam83F is induced in response to DNA damage and its overexpression also increases p53 activity in cell culture experiments and in zebrafish embryos. Downregulation of Fam83F decreases transcription of p53 target genes in response to DNA damage and increases cell proliferation, identifying Fam83F as an important regulator of the DNA damage response. Overexpression of Fam83F also enhances migration of cells harbouring mutant p53 demonstrating that it can also activate mutant forms of p53