MANUFACTURE OF SEMICONDUCTOR DEVICE

PURPOSE:To obtain a semiconductor device formed with a solder layer on the back surface electrode in less number of steps by enabling to simultaneously performing the step of dividing a molten solder layer formed on the overall area of the back surface of a wafer and the solder layer of the back surface electrode corresponding to the respective elements and the step of exposing lattice grooves from the molten solder layer. CONSTITUTION:Lattice grooves 4 for dividing the elements 2 at the side of the back surface electrode 3 of a wafer 1 are more deeply opened than the back surface electrode 3 by a thin abrasive or photoetching, and the silicon surface is exposed from the electrodes 3. The molten solders 8, 8a contacted with the electrodes 3 are excellent in wettability, and are rigidly contacted with the electrodes 3. On the other hand, molten solders 7, 7a buried in the grooves 4, 4a are contacted with the silicon surface of the wafer 1. Accordingly, the wettability is very bad, and the solders are solidified to molten solders 8, 8a contacted with the electrodes 3 by means of surface tension. As a result, the grooves 4, 4a are exposed, and the layer 11 divided via the grooves 4 solidified on the electrodes 3, thereby forming a solder layer 11.