Investigation of Surface Pre-Treatment Methods for Wafer-Level Cu-Cu Thermo-Compression Bonding.

To increase the yield of the wafer-level Cu-Cu thermo-compression bonding method, certain surface pre-treatment methods for Cu are studied which can be exposed to the atmosphere before bonding. To inhibit re-oxidation under atmospheric conditions, the reduced pure Cu surface is treated by H2/Ar plasma, NH3 plasma and thiol solution, respectively, and is covered by Cu hydride, Cu nitride and a self-assembled monolayer (SAM) accordingly. A pair of the treated wafers is then bonded by the thermo-compression bonding method, and evaluated by the tensile test. Results show that the bond strengths of the wafers treated by NH3 plasma and SAM are not sufficient due to the remaining surface protection layers such as Cu nitride and SAMs resulting from the pre-treatment. In contrast, the H2/Ar plasma⁻treated wafer showed the same strength as the one with formic acid vapor treatment, even when exposed to the atmosphere for 30 min. In the thermal desorption spectroscopy (TDS) measurement of the H2/Ar plasma⁻treated Cu sample, the total number of the detected H2 was 3.1 times more than the citric acid⁻treated one. Results of the TDS measurement indicate that the modified Cu surface is terminated by chemisorbed hydrogen atoms, which leads to high bonding strength.

Addiction and Engagement: An Explorative Study Toward Classification Criteria for Internet Gaming Disorder.

The DSM-5 introduced Internet gaming disorder (IGD) as a condition needing more research. Proposed criteria include tolerance, preoccupation, deceiving, or continued excess despite psychosocial problems. However, studies suggest differences between addicted and engaged players. Therefore, this study investigated differences between engagement and addiction in a German-speaking sample of expert World of Warcraft players. Using an online-based questionnaire, 682 participants were surveyed (Mage=23.26 years; 84.9% male) from German-speaking areas. An adapted version of the "Asheron's call" questionnaire (which covers six addiction criteria, including salience, euphoria, and tolerance), the WHOQOL-BREF, the Gaming Motivation Scale, the BDI, the SPIN, and a brief version of the personality questionnaire BFI-10 were used. The average gamer in the sample played on level 87.93 and had been playing for 5.42 years. Addicted players had higher scores on the BDI and SPIN and significantly lower scores in all dimensions of quality of life. Addicted gamers played for 39.25 hours per week (engaged players: 11.93 hours per week) with significantly higher scores in items tapping achievement and immersion. There were differences regarding the BFI-10 in terms of "agreeableness," "conscientiousness," and "neuroticism." The results suggest that factors such as achievement and immersion set engaged and addicted users apart. Addiction seems to be significantly more connected to other psychopathologies such as depression and social anxiety. The results suggest that euphoria, tolerance, and cognitive salience should be handled with caution when it comes to a classification of IGD similar to (behavioral) addiction.