The present invention contemplates preventing clogging of a dicer for forming separation trenches in a semiconductor wafer, and as well improving the yield of a semiconductor device cut out of the semiconductor wafer. A second adhesive to be charged into spaces contains an epoxy material as a base material. Silica filler particles (diameter: about 2 to about 4 .mu.m) are added to the base material in an appropriate amount. Charging of the second adhesive may be performed by adding the adhesive dropwise to a side wall of a semiconductor wafer, or by immersing an edge of the semiconductor wafer in the adhesive in the form of liquid. When a liquid-form epoxy material of low viscosity is employed, the spaces can be evenly filled with the second adhesive by capillary action. An n-electrode is formed on an exposed surface of an n-type layer through vapor deposition employing a resist mask. Separation trenches are formed through half-cut dicing from the exposed surface of the n-type layer toward the second adhesive.