Surfactants on the surface of copper wafer for wetting behavior research

• Main Authors: Ching-Biau Wang, 王清標
• Other Authors: Heng-Kwong Tsao
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/wu32b3

碩士 === 國立中央大學 === 化學工程與材料工程研究所 === 94 === In this paper, we can know that the semiconductor production process, especially the Post CMP process is very important. The Post CMP cleaning can let to know how to research the phenomena of copper surface. We present our method for the measurement of contact angles on the surface of copper wafer cleaning process because the standard deviation obtained in our measurements achieved unexpectedly low error. DSA-10 equipment that construction of a goniometer connected with a specially prepared computer program allowed us to repeat measurements several times over a short time course, yielding excellent results. After defining points on the outline of the image of a drop and its baseline as well of the first approximation of the outline of the drop, an iterative process is initiated that is aimed at fitting the model of the drop and baseline. The measurements were made, the work of adhesion is determined according to Young’s equation. In this study, the main to observe wetting behavior phenomena solders which surfactants on the copper wafer. No sooner had the surface wet than the contact angle became lower. It is represented that surface energy is lower. Example, DI-water wet on the copper wafer surface of cuprous oxide that contact angle is 100° and the surface is very hydrophobic. The surface energy is highly on the surface of copper wafer. For avoid to the defects on the surface, such as the metal ions and the water mark were remained. In this study, we add the surfactants in the DI-water solvent to research wetting behavior on the copper wafer. In our experiment, we can found the dynamic contact angle that measurement time is 30th seconds and the angle variable is stable status. When the critical micelle concentration (CMC) reach tenth times that the angle variable is the lowest. That is show the cleaning solution that include the surfactants is status in 30th dynamic contact angle and 10th CMC. In compare to the cation and anion of surfactant, we can observe that have the same characteristic type surfactant, having the same head group and the different tail chain. In order to compare the tail chain affects the wet behavior on the surface of copper that we do experiment about the SDS and DTAB different tail chain effect. We can find that when the carbon tail chain is longer, it wetting ability is more hydrophilic. With double tail chain surfactant, as like the DDAB and AOT that contact angle can lower than 30 degree. When use SDS types surfactant to immerse the DI-water that the contact angle can recover to 95 degree. That approach to the initial number 100 degree. It is show that surface energy recovers initial status. Add to the acid, alkali and salt solution to decrease the contact angle for wetting the surface of copper wafer.