| 摘要 |
PROBLEM TO BE SOLVED: To prevent cracks from occurring on a semiconductor substrate due to the difference in thermal expansion coefficient caused by a change in temperature between a semiconductor substrate and a metal layer. SOLUTION: An insulator coating 20 is formed in a ring so as to cover the boundary between the outer circumferential edge of a P-type diffusion layer 12 and an N-type semiconductor on a semiconductor substrate 11, a contact metal layer 15 is laminated on the surface of the semiconductor substrate 11 inside the insulator coating 20, and a stress relaxing intermediate layer 30, a cushion electrode layer 16 and a lead-out layer 17 are formed so as to cover the surfaces of the contact metal layer 15 and the insulator coating 20. The insulator coating 20 is made of a silicon dioxide coating 13 and a nitride coating 14 having an etching rate smaller than that of the silicon dioxide coating 13. The stress relaxing intermediate layer 30 has a linear expansion coefficient more approximate to the semiconductor substrate 11 than to the stress relaxing metal layer 16. The extraction electrode layer 17 (e.g. Ni) has a smaller etching rate for a surface treatment agent than that of the cushion electrode layer 16 (e.g. Al). COPYRIGHT: (C)2011,JPO&INPIT |
