Abstract: A manufacturing method for a device chip includes a wafer preparation step of preparing a wafer including a base substrate, a laser beam absorbing layer layered on a front surface of the base substrate, and a device layer being layered on the laser beam absorbing layer and having devices formed in respective separate regions demarcated by a plurality of crossing division lines, a device layer dividing step of forming respective division grooves that divide at least the device layer into individual device chips along the plurality of division lines, and a lift-off step of, after the device layer dividing step is carried out, applying a laser beam of such a wavelength as to be absorbed in the laser beam absorbing layer, from the base substrate side, and lifting off a device chip from the front surface of the base substrate.

Abstract: There is provided a wet etching method including an etchant supply step of supplying an etchant from an etchant supply nozzle to a to-be-etched surface of a workpiece, an etching step of etching the to-be-etched surface with the etchant remaining on the to-be-etched surface, and an etchant removal step of, after performing the etching step, removing the etchant, which still remains on the resulting etched surface, from the etched surface. The etchant supply step, the etching step, and the etchant removal step are repeated a plurality of times in this order.

Abstract: A gettering layer forming method includes a coating step of applying a solution of metal salt to a back side of a wafer, and a diffusing step of heating the wafer after performing the coating step, thereby diffusing the metal salt on the back side of the wafer to form a gettering layer containing the metal salt on the back side of the wafer, in which the metal salt is diffused in the gettering layer.

Abstract: A gettering layer forming method includes a coating step of applying a solution of metal salt to a back side of a wafer, and a diffusing step of heating the wafer after performing the coating step, thereby diffusing the metal salt on the back side of the wafer to form a gettering layer containing the metal salt on the back side of the wafer, in which the metal salt is diffused in the gettering layer.

Abstract: A laser processing method including the steps of covering the back side of a workpiece with fine particles having absorptivity to the wavelength of a laser beam to be applied to the workpiece, thereby forming a fine particle layer on the back side of the workpiece, and next applying the laser beam through the fine particle layer to the back side of the workpiece to thereby perform ablation to the workpiece. The laser beam applied to the workpiece is absorbed by the fine particle layer to thereby suppress the scattering of the energy of the laser beam and the reflection of the laser beam, so that the ablation to the workpiece can be efficiently performed.