Manufacture of semiconductor element

Abstract

Abstract PURPOSE:To obtain stable characteristics by forming a recess surrounded by an oblique face at each of a plurality of bases on one face of a substrate, forming an opposite conductivity type layer to that of the substrate, forming a mesa groove which has the outer periphery of an opening on the surface near the periphery of the base and narrows toward its bottom, and so cutting the substrate as to pass the bottom of each groove. CONSTITUTION:After one face of an n<-> type silicon substrate is formed with parts covered with a resist film in a lattice state, recesses 8 are formed by etching, an impurity is diffused in its whole face, a P<+> type layer is formed on the side having the recesses and an N<+> type layer 3 is formed on the other side. In this case, an oblique face 41 is formed at a P-N junction between the original N<-> type layer 1 of the substrate. Then, the inner face of the recess 8 and the narrow part of the flat face of the outer periphery are protected with resist films, a base for surrounding the recess is etched to the depth exceeding the junction to form a mesa groove 5. Then, the inner face of the groove 5 is covered with a passivation film 6, and cut into diode chips at the cutting face of a chain line 7. Thus, high breakdown strength and stable characteristics are obtained.

Inventors

• 👤 Kenji Suzuki
• 👤 健司 鈴木

Bibliographic Details