Establishment of a theoretical model for calculating the thickness of chemical reaction layer of sapphire substrate to slurry and the related experimental analysis

• Main Authors: Hao-yang Ding, 丁晧洋
• Other Authors: Zone-Ching Lin
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/91116707597936202490

碩士 === 國立臺灣科技大學 === 機械工程系 === 102 === The paper innovatively proposes a theoretical model for estimating the thickness of chemical reaction layer of sapphire wafer substrate, which is affected by and under chemical reaction to slurry. Atomic force microscopy (AFM) experiment is made to estimate the values of specific down force energy (SDFE) under different slurry soaking condidtions. For the conditions of slurry in the experiment, the lengths of soaking time in slurry are 5 minutes, 10 minutes, 30 minutes, 60 minutes and 90 minutes; the temperatures of slurry for soaking are 20℃, 30℃, 40℃ and 50℃; and the volume concentrations of slurry are 10%, 20%, 30%, 40% and 50%. Under different slurry soaking conditions, the paper explores the effects of chemical reaction to slurry on the thickness of chemical reaction layer of sapphire wafer substrate. In the experiment of the study a smaller down force is used to carry out AFM cutting of sapphire wafer substrate before soaking in slurry, achieving the SDFE value of sapphire wafer substrate not being soaked in slurry. Then a much smaller down force is used to carry out AFM cutting of sapphire wafer substrate soaked in slurry under different slurry soaking conditions, obtaining the SDFE value of the thickness of chemical reaction layer of sapphire wafer substrate to slurry after substrate is soaked in slurry. After that, employing a depth interval 5A and down force to carry out AFM cutting, the paper observes the SDFE value of the chemical reaction layer. When the SDFE value in the experiment increases step by step from stability, it represents that the AFM probe has gradually pressed down from chemical reaction layer to the raw material. Therefore, the change of SDFE value becomes an important target. With SDFE equation as theoretical foundation, the paper develops an inverse calculation method of the thickness of chemical reaction layer, and calculates the thickness of chemical reaction layer. With the concept of SDFE, the paper further inversely calculates the thickness of chemical reaction layer produced on sapphire wafer substrate after being affected by chemical reaction to slurry. Finally, the paper conducts AFM experiment and takes a depth interval 1A for experimental cutting, and verifies that the method of inversely calculating the thickness of chemical reaction layer is feasible. With SDFE theoretical equation, the study derives and establishes an innovative calculation method of the thickness of chemical reaction layer of sapphire wafer substrate. After acquiring the thicknesses of chemical reaction layer of sapphire wafer substrate and SDFE values from experiment, the paper further uses inverse calculation method to obtain the thicknesses of chemical reaction layer of sapphire wafer substrate, which is then compared with the experimental results to find the difference. Finally, using regression theoretical analysis, the paper can obtain the regression equations of the thickness of chemical reaction layer of sapphire wafer substrate under different slurry soaking conditions. Meanwhile, by using the obtained regression equation, the paper estimates and anticipates the required soaking time, temperature of slurry for soaking and volume concentration of slurry for forming a thickness of chemical reaction layer on sapphire wafer substrate after being soaked in slurry. Experimental analysis results show that when the soaking time in slurry lengthens, slurry temperature rises and volume concentration of slurry increases, then the chemical reaction layer formed by chemical reaction of sapphire wafer substrate to slurry is increased. As to academic innovation of the study, SDFE theory is used to inversely calculate the thickness of chemical reaction layer produced by chemical reaction of sapphire wafer substrate to slurry. Besides, after it is attached with the equations regression theoretical analysis, the study can anticipate the thickness of chemical reaction layer produced by different slurry soaking conditions. Furthermore, the research results have significant referential and application values when being applied by industries to chemical mechanical polishing of sapphire wafer substrate.