Method for manufacturing semiconductor substrate, method for manufacturing damascene wiring structure, semiconductor substrate, and damascene wiring structure

A damascene wiring structure comprising a semiconductor substrate, an insulating layer, a metal layer, a wiring portion, and a cap layer, wherein

• the semiconductor substrate includes a main surface provided with a recess,
• the recess has a bottom surface, a side surface, and an inclined surface,
• the inclined surface is connected to the bottom surface and the side surface between the bottom surface and the side surface, and is inclined with respect to the bottom surface and the side surface so as to form an obtuse angle with the bottom surface and the side surface, and
• a plane orientation of the bottom surface, a plane orientation of the side surface, and a plane orientation of the inclined surface are different from each other,
• the recess is a groove extending along the main surface,
• the insulating layer has a first portion provided on an inner surface of the groove and a second portion formed integrally with the first portion and provided on the main surface,
• the metal layer is provided on the first portion of the insulating layer,
• the wiring portion is formed on the metal layer embedded in the groove, and
• the cap layer is provided so as to cover the second portion of the insulating layer, an end of the metal layer, and the wiring portion.