Study on defect reduction for high aspect ratio etch process
Increasing data needs much larger memory capacity. One of the Flash Memory Solution is Vertical NAND (V-NAND) Flash Memory. In order to fabricate this device, a high aspect ratio hole must be made in the channel hole through the etching process after multilayer thin film deposition. In order to obtain high aspect ratio etch, process condition should have high RF power, high flow rate of polymer gas, and long process time. This harsh etch condition results in high ion energy and lots of polymer production. It can create defects like fluorocarbon polymer and arcing. In this study, we studied arcing mechanism. Here we defined various margins for arcing-free and optimized the focus ring. And we improved pumping conductance for polymer discharge. This study removed defects and obtained arcing-free during V-NAND etch process.
Bevel RIE application to reduce defectivity in copper BEOL processing
Bevel etch used during wafer fabrication for semiconductor devices is discussed. In this case, the bevel etch process was utilized in middle of the line processing (MOL) to reduce back end of line (BEOL) defectivity. Tungsten and titanium nitride films, from the formation of contacts to the transistors, extend into the bevel region of the wafer and have been shown to initiate arcing. This can spread foreign material defects on the front side of the wafer in various BEOL post processing steps including subsequent reactive ion etching, SEM metrology and film depositions. The bevel etch tool confines a plasma etch to the outer edge of the front side of the wafer (which can be individually adjusted) and can remove dielectric, organic and Ti/TiN/W films using a fluorine based chemistry.
Efficacy of life skills training on general health in students
BACKGROUND
With regard to the importance of life skills, the present study deals with the effect of life skills training on general health of the students.


MATERIALS AND METHODS
This was a one-group, pre-test, post-test, quasi-experimental research. Forty students were selected through purposive sampling method. The data collection tool was Goldberg General Health Questionnaire.


RESULTS
Paired t-test showed a 22 score significant decrease in general health after education compared to before education (P < 0.01).


CONCLUSION
This study showed that life skills education increases general health level of the students.