2017 年 83 巻 2 号 p. 167-172
This paper focuses on the thermal cleavage of a laminated wafer on which the borosilicate glass substrate is bonded on the silicon wafer. The semiconductor laser beam with an elliptical shape is applied to generate the thermal distribution inside the laminated wafer. The carbon dioxide laser is also used to improve the cleavage quality at the final edge of laminated wafer. The crack propagation during laser beam irradiation is observed by acoustic emission sensor, and the influence of physical and thermal property in each material on the crack propagation is evaluated. As results, the crack propagation in laminated wafer was achieved by the absorption to the silicon of semiconductor laser and the thermal conduction to the borosilicate glass by the generated heat inside the silicon. At the start edge in laminated wafer, the crack propagated only inside the silicon due to the difference of the absorption coefficient and the thermal properties in silicon and borosilicate glass. At the final edge in laminated wafer, the cleavage characteristic was improved by applying the CO2 laser beam for the purpose of adding the input energy to the borosilicate glass.