| Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 105 === Abstract
The paper uses down force to perform atomic force microscopic (AFM) machining of single-crystal silicon substrate unsoaked in slurry, and obtains the specific down force energy (SDFE) in the range of the single-crystal silicon substrate unsoaked in slurry. After that, the paper uses a smaller down force to conduct AFM machining experiment of the single-crystal silicon soaked in room-temperature slurry. Using SDFE theory, the paper acquires the SDFE of the single-crystal silicon’s chemical reaction layer soaked in room-temperature slurry. The paper also uses the theoretical model and experimental method for calculating the thickness of the chemical reaction layer soaked in room-temperature slurry, to obtain the thickness of the chemical reaction layer of the single-crystal silicon soaked in room-temperature slurry. Under the circumstances that the pressing depth is fixed within the thickness of chemical reaction layer, the paper SDFE equation to derive the down force size of the single-crystal silicon soaked in room-temperature slurry at such a fixed pressing depth. The paper proposes an innovative method for calculating the bonding energy of Morse potential energy for the single-crystal silicon affected by chemical reaction of room temperature slurry. For this calculation method, it is firstly supposed that the parameters α and r0 for Morse potential energy of single-crystal silicon to be affected by slurry is unchanged, and only the bonding energy D value is changed. Therefore, it is initially predicted that D value is the bonding energy D value of Morse potential energy of the single-crystal silicon unsoaked in slurry, and is used for testing. Employing the concept of inverse method, the paper firstly lets the initial value be D, and then uses molecular statics nanocutting model to simulate the down force at a fixed pressing depth, and then compares it with the down force at a fixed pressing depth calculated by the SDFE of the single-crystal silicon affected by room temperature slurry. Based on the difference in down force resulted after comparison, the paper uses optimization concept to step by step adjust the D value of Morse potential energy, and then uses molecular statics nanocutting model to simulate the down forces of the different D value at a fixed pressing depth and takes the ratio of distance between the two down forces calculated by the above two methods, which should be smaller than the convergence value, as the objective function. When objective function reaches the convergence value, it is supposed that the calculated D value is the bonding energy D value of Morse potential energy of the single-crystal silicon affected by the chemical reaction when being soaked in room temperature slurry. The study finally uses the calculated bonding energy D value of Morse potential energy of the single-crystal silicon affected by room temperature slurry, and uses molecular statics nanocutting model to simulate the cutting force and down force for cutting single-crystal silicon. The paper also compares them with the cutting force and down force affected by room temperature slurry, which are calculated by SDFE method. is tested and verified that the acquired bonding energy D value of Morse potential energy affected by room temperature slurry is reasonable. Besides, the paper also uses the bonding energy D value of Morse potential energy affected by room temperature slurry to simulate, using molecular statics nanocutting equation, the equivalent stress for nanocutting of single-crystal silicon and distribution of equivalent stress, as well as the temperature rise and temperature distribution caused by friction heat source and plastic heat source. Furthermore, the paper makes analysis after comparing with the cutting results of the single-crystal silicon unsoaked in slurry achieved in the past literature.
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