Manufacturing process for high aspect ratio metallic micro parts made by electroplating on partially conductive templates

Extended Abstract In supporting structural integrity of a miniature component, or for providing electric conduction of a through-silicon via (TSV) in three-dimensional integrated circuits (3D-IC), micro-or nano-hole filling with metallic material becomes increasing important in various micro-electrical mechanical systems (MEMSs) In this study, an anodic aluminum oxide (AAO) template containing numerous high aspect ratio nano-sized holes (an average diameter of 130 nm and an aspect-ratio about 20) was used as the cathode. The hydrophobicity/hydrophilicity of the AAO template was adjusted before Cu electrodeposition. Electrodeposition of Cu was carried out in an emulsified sc-CO2 bath containing cupric sulfate aqueous solution as the precursor. Cu deposition into the nano-holes was performed at an apparent constant current density of 2 A/dm 2 for 5 minutes. After electrodeposition, the cross section morphology and chemical composition of the AAO cathode was examined by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) with the aid of a focused-ion-beam (FIB). The experimental results showed that electrodeposition employing sc-CO2 bath to fill Cu into nano-sized holes was successful and superior to that of conventional process carried out at ambient pressure, in terms of uniformity and deposition rate. The high solubility of hydrogen gas in sc-CO2 fluid is the key factor. Moreover, the advantage of sc-CO2 electrodeposition is more pronounced for the AAO cathode exhibiting hydrophobic nature with respect to aqueous bath. References [1] Z

Heterogeneous 2.5D integration on through silicon interposer

© 2015 AIP Publishing LLC. Driven by the need to reduce the power consumption of mobile devices, and servers/data centers, and yet continue to deliver improved performance and experience by the end consumer of digital data, the semiconductor industry is looking for new technologies for manufacturing integrated circuits (ICs). In this quest, power consumed in transferring data over copper interconnects is a sizeable portion that needs to be addressed now and continuing over the next few decades. 2.5D Through-Si-Interposer (TSI) is a strong candidate to deliver improved performance while consuming lower power than in previous generations of servers/data centers and mobile devices. These low-power/high-performance advantages are realized through achievement of high interconnect densities on the TSI (higher than ever seen on Printed Circuit Boards (PCBs) or organic substrates), and enabling heterogeneous integration on the TSI platform where individual ICs are assembled at close proximity

Bright light treatment of depression for older adults [ISRCTN55452501]

BACKGROUND: The incidence of insomnia and depression in the elder population is significant. It is hoped that use of light treatment for this group could provide safe, economic, and effective rapid recovery. METHODS: In this home-based trial we treated depressed elderly subjects with bright white (8,500 Lux) and dim red (<10 Lux) light for one hour a day at three different times (morning, mid-wake and evening). A placebo response washout was used for the first week. Wake treatment was conducted prior to the initiation of treatment, to explore antidepressant response and the interaction with light treatment. Urine and saliva samples were collected during a 24-hour period both before and after treatment and assayed for aMT6s and melatonin respectively to observe any change in circadian timing. Subjects wore a wrist monitor to record light exposure and wrist activity. Daily log sheets and weekly mood (GDS) and physical symptom (SAFTEE) scales were administered. Each subject was given a SCID interview and each completed a mood questionnaire (SIGH-SAD-SR) before and after treatment. Also, Hamilton Depression Rating (SIGH-SAD version) interviews were conducted by a researcher who was blind to the treatment condition. A control group of healthy, age-matched, volunteers was studied for one day to obtain baseline data for comparison of actigraphy and hormone levels. RESULTS: Eighty-one volunteers, between 60 and 79 years old, completed the study. Both treatment and placebo groups experienced mood improvement. Average GDS scores improved 5 points, the Hamilton Depression Rating Scale (HDRS) 17 scores (extracted from the self-rated SIGH-SAD-SR) improved 6 points. There were no significant treatment effects or time-by-treatment interactions. No significant adverse reactions were observed in either treatment group. The assays of urine and saliva showed no significant differences between the treatment and placebo groups. The healthy control group was active earlier and slept earlier but received less light than the depressed group at baseline. CONCLUSION: Antidepressant response to bright light treatment in this age group was not statistically superior to placebo. Both treatment and placebo groups experienced a clinically significant overall improvement of 16%