Research On Vibration Transmission Of High Frequency Piezoelectric Vibrator And It’s Application In CMP

High frequency ultrasonic vibration was introduced in chemical mechanical polishing ofsilicon wafer in this paper, Aiming at contact chemical mechanical polishing, this paperpropose a novel method of CMP with high energy and strong penetrability high frequencyultrasonic vibration assisted. Produced vibration system which is non-integral resonance withthe polishing tool, applied to chemical mechanical polishing of silicon wafer.This paper make a detailed description of the working principle of high frequency waferpiezoelectric vibrator, liquid medium is used to transmit vibration, vibration system andpolishing tool flexiblly connected. High frequency ultrasonic piezoelectric vibrator is inresonance mode, workpiece and particles in polishing liquid obtain the vibrational energyfrom acoustic propagation, without integral Modal design, achieved succinct a vibrationpolishing tool. Using ANSYS simulation analyzed the1.7MHz high frequency waferpiezoelectric vibrator, no-load test and liquid load test of the piezoelectric vibrator were alsoconducted, and the reasons why there is difference between simulation analysis and actual testwere explained. Based on the theory of sound wave transmission, polishing tool was designedaccording to acoustic matching, so vibrational energy can high efficient effect on polishinginterface. Design and construction the additional vibration system and polishing experimentsystem in the high frequency ultrasonic polishing system, measured and macroscopicobserved the vibration transmission capacity of the system. Chemical mechanical polishingexperiments of silicon wafer were conducted with high frequency ultrasonic vibration assistedpolishing experiments show that under the specific experimental parameters, high frequencyvibration effectively reduced the wafer surface roughness vastly.