MANUFACTURE OF SEMICONDUCTOR DEVICE

PURPOSE:To contrive prevention of lateral spike diffusion, stabilization of element characteristics and to achieve a long lifetime of an element by a method wherein, after an epitaxial layer has been selectively removed, and a mask layer has been formed by performing a lithographic method, impurities are selectively diffused using said mask layer. CONSTITUTION:An n type clad layer 3 consisting of n type GaAlAs, an active layer 4 consisting of GaAs, a p type clad layer 5 consisting of p type GaAlAs, a cap layer 6 consisting of n type GaAs, and a screen layer 11 consisting of Ga1-xAlxAs (x>=0.4) are formed successively. The screen layer 11 is partially removed, and a mask layer 12 with which the cap layer part opposing to the channel 2 will be exposed is formed. When Zn is diffused on the whole main surface of a wafer 10, a contact region 7 with which ohmic contact will be obtained is formed. An anode electrode 8 is formed on the whole main surface of the wafer 10, and a cathode electrode 9 is formed on the lower surface of the wafer 10. After a cleavage has been formed on the wafer 10 along the plane of cleavage orthogonally intersecting with the channel 2 by applying external force, an element is obtained by cutting the wafer at the intermediate part of a channel 2 and another channel 2.