Comparison of oxidation in uni-directionally and randomly oriented Cu films for low temperature Cu-to-Cu direct bonding.

Cu-to-Cu direct bonding has attracted attention because it has been implemented in CMOS image sensors. Prior to the bonding, the oxides on the Cu surface needs to be removed, yet the surface may oxidize right after cleaning. Thus, oxidation is an inherent issue in the application of Cu direct bonding. Our previous study reported that Cu direct bonding can be achieved below 250 °C by using (111)-oriented nanotwinned Cu because it has the fastest surface diffusivity. However, the oxidation behavior of the nanotwinned Cu is unclear. Here, we examined the oxidation behavior of highly (111) and (200) oriented, and randomly-oriented Cu films at temperatures ranging from 120 to 250 °C. Transmission electron microscopy was used to measure the oxide thickness. The results show that the oxidation rate of (111)-oriented nanotwinned Cu has the lowest oxidation rate among them. Together, it is unique to possess the combination of the fastest surface diffusivity and the lowest oxidation rate.

Out of sight, out of mind? The inclusion and identification of people with intellectual disability in public health research.

AIMS: Adults with intellectual disability experience substantial health inequities. Public health research aiming to improve the lives of this population group is needed. We sought to investigate the extent to which a sample of international public health research includes and identifies people with intellectual disability. METHODS: In this systematic review, we examined a select number of public health journals to determine (1) how often people with intellectual disability are explicitly included in randomised controlled trials (RCTs) and cohort studies and (2) how the presence of intellectual disability is identified and reported. RESULTS: Among eligible articles in these selected public health journals, it was found that cohort studies passively exclude people with intellectual disability, while RCTs actively exclude this population. Most general population articles that explicitly identified people with intellectual disability did so through self-report or proxy report and databases. CONCLUSIONS: A more extensive and adequate evidence base relating to the health of this overlooked population group is needed. A useful first step would be for researchers specialising in intellectual disability to identify how we can best assist mainstream researchers to include and identify people with intellectual disability in their population-level studies.