Method of manufacturing optical detection element and optical detection element

A method of manufacturing an optical detection element, comprising:

• a first process of forming an amorphous semiconductor layer on a support;
• a second process of forming a first metal layer on the semiconductor layer;
• a third process of carrying out a heat treatment so that the semiconductor layer is polycrystallized and the semiconductor layer and the first metal layer are interchanged with each other, thereby forming the first metal layer on the support and forming a polycrystalline photoelectric conversion layer on the first metal layer;
• and
• a fourth process of forming a second metal layer on the photoelectric conversion layer,
• wherein in the fourth process, the second metal layer is formed so that a width of the second metal layer in a first direction orthogonal to a thickness direction of the second metal layer becomes a width with which surface plasmon resonance occurs due to incidence of light in a predetermined wavelength region.