Semiconductor structure

A reflective structure, comprising:

• a first metal base and a second metal base over an interconnect structure;
• a first dielectric film having a first thickness on the first metal base and a second thickness on the second metal base, the first thickness being different from the second thickness;
• a second dielectric film on the first dielectric film, having a third thickness over the first metal base and a fourth thickness over the second metal base, the third thickness being different from the fourth thickness;
• and
• a third dielectric film on the second dielectric film, having a fifth thickness over the first metal base and a sixth thickness over the second metal base, the fifth thickness being different from the sixth thickness;
• wherein a refractive index of the first dielectric film is smaller than a refractive index of the second dielectric film, and the refractive index of the second dielectric film is smaller than a refractive index of the third dielectric film.

A semiconductor structure, comprising:

• a metallization structure;
• a plurality of conductive pads over the metallization structure;
• and
• a dielectric layer on the metallization structure and covers the conductive pad, the dielectric layer comprising:
• a first dielectric film on the conductive pad;
• a second dielectric film on the first dielectric film;
• and
• a third dielectric film on the second dielectric film;
• wherein a refractive index of the first dielectric film is smaller than a refractive index of the second dielectric film, and the refractive index of the second dielectric film is smaller than a refractive index of the third dielectric film.