| 摘要 |
PURPOSE:To obtain the manufacturing method of the guard ring of a semiconductor element using a heterojunction, in which voltage breakdown due to sufficient multiplication occurs in a light receiving region before the voltage breakdown is yielded in the guard ring, by setting the width of a cap layer within a specified range, implanting ions, and providing a P-N junction. CONSTITUTION:A light absorbing layer 3 having a forbidden band width of at least Eg1, an avalanche multiplying layer 4 having a forbidden band width of Eg2 (Eg2>Eg1), and cap layer 4' having a concentration lower than that of the avalanche multiplying layer 4 are laminated. A P-N junction is provided selectively in the avalanche layer 4 and the cap layer 4' by ion implantation. In this manufacturing method of a compound semiconductor light receiving element, the thickness D of the cap layer 4' is set so that relationship RP<=D<=4RP, where RP is the projecting distance of the implanting ions used for forming the P-N junction, is obtained. For example, the thickness of the cap layer 4' is set within said range. Thereafter, a window is provided in an insulating film 11 by an ordinary exposure technology. Ions are implanted in a region 11' selectively, and a region 5'' is provided. Thereafter, the surface of the semiconductor is coated by a heat-treatment protecting film 12. Heat treatment is performed, and a P-N junction 5' is formed. |
