A Comparative Study of Ti/Low-k HSQ (Hydrogen Silsesquioxane) and Ti/TEOS (Tetraethylorthosilicate) Structures at Elevated Temperatures

2000 ◽  
Vol 612 ◽  
Author(s):  
Yuxiao Zeng ◽  
Linghui Chen ◽  
T. L. Alford
Keyword(s):  
Comparative Study ◽  
Direct Contact ◽  
Elevated Temperatures ◽  
Primary Source ◽  
Hydrogen Silsesquioxane ◽  
Titanium Layer ◽  
To Come ◽  
Al Metallization ◽  
Interconnect Technology ◽  
Low K

AbstractFor the benefit of reducing capacitance in multilevel interconnect technology, low-k dielectric HSQ (hydrogen silsesquioxane) has been used as a gapfill material in Al-metallization- based non-etchback embedded scheme. The vias are consequently fabricated through the HSQ layer followed by W plug deposition. In order to reduce the extent of via poisoning and achieve good W/Al contact, thin Ti/TiN stack films are typically deposited before via plug deposition. In this case, HSQ makes direct contact with the Ti layer. The reliability of the Ti/HSQ structures at elevated temperatures has been systematically studied in this work by using a variety of techniques. These results are also compared with those from Ti/TEOS (Tetraethylorthosilicate) structure, where TEOS is a conventional intra-metal dielectric. When the temperature is below 550 °C, a significant number of oxygen atoms are observed to diffuse into the titanium layer. The primary source of oxygen is believed to come from the HSQ film. When the temperature is above 550 °C, HSQ starts to react with Ti. At 700 °C, a TiO/Ti5Si3/HSQ stack structure forms. The Ti/HSQ system exhibits a higher reactivity than that of the Ti/TEOS system.

A comparative study on the measurement of toughness of stacks containing low-k dielectric films

2008 ◽  
Vol 85 (11) ◽  
pp. 2322-2328 ◽  
Author(s):  
Z.W. Zheng ◽  
I. Sridhar ◽  
S. Balakumar
Keyword(s):  
Comparative Study ◽  
Dielectric Films ◽  
Low K

scholarly journals Build me up to break me down: frothed spawn in the sandpaper frog, Lechriodus fletcheri, is formed by female parents and later broken down by their offspring

2019 ◽  
Vol 67 (3) ◽  
pp. 153
Author(s):  
John Gould
Keyword(s):  
Surface Area ◽  
Embryo Development ◽  
Direct Contact ◽  
Open Water ◽  
Air Bubbles ◽  
Temporal Shift ◽  
External Stresses ◽  
Resultant Increase ◽  
To Come ◽  
Over Time

Several genera of anuran amphibians deposit their eggs within mucous secretions that have been aerated by the parents to produce a foam or bubble spawn body. This is a dynamic medium for embryo development given that it gradually breaks down over time, and one that has been hypothesised to serve a variety of purposes including protecting embryos from external stresses, such as suboptimal temperatures, desiccation and predation. In this study, I provide additional details of bubble spawn production in the sandpaper frog, Lechriodus fletcheri. Field and laboratory observations showed that females aerate spawn while in inguinal amplexus, using flanged fingers to transport air bubbles into the mucous. While the frothed spawn is initially resistant to breakdown, it gradually loses bubbles and flattens out into a film. This temporal shift in structure is likely to be adaptive, as the resultant increase in surface area allows embryos to come in direct contact with the open water, which may accommodate their increased oxygen demands or ease extrication from the mass. I provide evidence that this process is controlled by the residing embryos, given that spawn in the absence of embryos does not break down, highlighting the ability of offspring to modify their immediate environment even before hatching occurs to ensure conditions remain suitable for their changing needs.

A Comparative Study on Undergraduate Computer Science Education between China and the United States

2015 ◽  
pp. 918-933
Author(s):  
Eric P. Jiang
Keyword(s):  
United States ◽  
Science Education ◽  
Comparative Study ◽  
Computer Science ◽  
Computer Science Education ◽  
Primary Source ◽  
The United States ◽  
Education Systems ◽  
Public And Private ◽  
Computer Scientists

With the rapid growth of the Internet and telecommunication networks, computer technology has been a driving force in global economic development and in advancing many areas in science, engineering, health care, business, and finance that carry significant impacts on people and society. As a primary source for producing the workforce of software engineers, computer scientists and information technology specialists, computer science education plays a particularly important role in modern economic growth and it has been invested heavily in many countries around the world. This chapter provides a comparative study of undergraduate computer science programs between China and the United States. The study focuses on the current curricula of computer science programs. It in part is based on the author's direct observation from his recent visits to several universities in China and the conversations he had with administrators and faculty of computer science programs at the universities. It is also based on the author's over two decades experience as a computer science educator at several public and private American institutions of higher educations. The education systems in China and the United States have different features and each of the systems has its strengths and weaknesses. This is likely also true for education systems in other countries. It would be an interesting and important task for us to explore an innovative computer science education program, which perhaps blends the best features of different systems and helps better prepare graduates for the challenges working in an increasingly globalized world. We hope the study presented in this chapter provides some useful insights in this direction.

scholarly journals Decomposition of Cyanide from Gold Leaching Tailingsby Using Sodium Metabisulphite and Hydrogen Peroxide

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Dongzhuang Hou ◽  
Lang Liu ◽  
Qixing Yang ◽  
Bo Zhang ◽  
Huafu Qiu ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Comparative Study ◽  
Contact Time ◽  
Synergetic Effect ◽  
Economic Conditions ◽  
Gold Mine ◽  
Optimal Conditions ◽  
Gold Leaching ◽  
Sodium Metabisulphite ◽  
To Come

Cyanidation is widely used by most gold mine worldwide and will remain prevail in years (or decades) to come, while cyanide is hazardous, toxic pollutants whose presence in wastewater and tailings can seriously affect human and its environment; hence, it is necessary to control these contaminants. The purpose of this study was to examine the effects through the investigation of changes in pH, concentration, and contact time, and the optimal conditions were obtained. It has been proven that the decomposition of cyanide in solution and tailings increased as the alkalinity in the presence of 0.5 g/L Na2S2O5. An increase in H2O2 (30%) concentration (from 1 to 4 mL/L) increased the decomposition in solution, while the effect on removing cyanide was better when pH was 9 than 8 and 10 in tailings. The cyanide in tailings decreased in the first 4 h and increased after 4 h. The effective and economic conditions for maximum decomposition of cyanide from leach tailings are first treated in 0.5 g/L Na2S2O5 at pH 10 for 3 hours and then 2 mL/L H2O2 (30%) is added to the tailings at pH 9 for 4 hours through comparative study. The findings provide the basis to optimize the decomposition of cyanide from gold leaching tailings in mining or backfilling by using the synergetic effect of Na2S2O5 and H2O2.

The Concentration of Di(2-Ethylhexyl) Phthalate on a Flooring Surface in Dwelling House

2017 ◽  
Vol 893 ◽  
pp. 400-404
Author(s):  
Hyun Tae Kim ◽  
Shin Ichi Tanabe ◽  
Tae Woo Kim ◽  
Won Hwa Hong
Keyword(s):  
Direct Contact ◽  
Behavioral Characteristics ◽  
Indoor Environments ◽  
High Concentration ◽  
Dwelling House ◽  
Vacuum Cleaning ◽  
The Subject ◽  
To Come ◽  
Ethylhexyl Phthalate ◽  
Children’S Exposure

This study was measured the concentration level of contamination by DEHP on indoor flooring surfaces. It was confirmed that vacuum-cleaning of dust accumulated on flooring surfaces would not completely eliminate DEHP in the flooring. Unlike ceilings or walls, children are more prone to come in direct contact with flooring; meaning children’s bare skin is more likely to be exposed to high-concentration of DEHP on flooring surfaces. As children lick their hands that come in direct contact with the flooring, their chance of orally ingesting DEHP is likely to increase as well. Given these findings, it is considered important to assess children’s exposure to DEHP in indoor environments and assess the risks thereof by investing the subject in relation to behavioral characteristics of children.

Modeling of Air-Gap Membrane Distillation and Comparative Study with Direct Contact Membrane Distillation

2020 ◽  
Vol 59 (50) ◽  
pp. 21930-21947
Author(s):  
Sadaf Noamani ◽  
Shirin Niroomand ◽  
Masoud Rastgar ◽  
Mehdi Azhdarzadeh ◽  
Mohtada Sadrzadeh
Keyword(s):  
Comparative Study ◽  
Direct Contact ◽  
Membrane Distillation ◽  
Air Gap ◽  
Air Gap Membrane Distillation ◽  
Direct Contact Membrane Distillation

Improvement on Intrinsic Electrical Properties of Low-k Hydrogen Silsesquioxane/Copper Interconnects Employing Deuterium Plasma Treatment

2000 ◽  
Vol 147 (3) ◽  
pp. 1186 ◽  
Author(s):  
Po-Tsun Liu ◽  
Ting-Chang Chang ◽  
Ya-Liang Yang ◽  
Yi-Fang Cheng ◽  
Jae-Kyun Lee ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Plasma Treatment ◽  
Copper Interconnects ◽  
Deuterium Plasma ◽  
Hydrogen Silsesquioxane ◽  
Low K
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