Improved Surface Roughness of Diamond Wire Sawn Wafers Using Ultrasonic Vibration-Assist

Abstract

In order to improve the sawn-surface morphology of the wafers, ultrasonic vibration-assisted diamond wire sawing is studied in this paper. Experiments are conducted with and without applying vibrations in order to compare the effect of ultrasonic vibrations on surface characteristics of the sawn silicon. The surfaces without vibration super-imposed show the characteristics of typical sawn surfaces produced by diamond wire sawing consisting of crushed fragments and of lines parallel with the wire speed direction. While the surfaces of grooves produced ultrasonic vibration-assist displays intermittent patterns due to the recurring cutting action by diamond grits as a result of ultrasonic vibrations. The grooves produced by ultrasonic vibration-assisted wire sawing have higher hybrid parameters of the surface roughness (Sda and Sdq) compared to those without ultrasonic vibration-assisted attributed to the formation of intermittent patterns. The higher Sdq value is reported as favorable in the literature for better light absorption. The phase analysis shows no significant difference between the surfaces for all sawn grooves regardless of the application of vibrations. The spectra mainly consist of Si-IV, a-Si and Si-III and Si-XII. In summary, it is evident that the ultrasonic vibration-assisted diamond wire sawing process can improve the surface morphology of the sawn wafers.