Patent ID: 11934109
Assignee: ZHONGKE JINGYUAN ELECTRON LIMITED, BEIJING (CN)
Field: Optics (Instruments)
Classification: CPC G  H | IPC G  H

Claim 1:
2. The overlay alignment mark according to claim 1,
wherein the pair of solid features are designed to be in the form of two solid patterns having strip-shaped sections in the first layer respectively, both of which not only have central symmetry, to each other, about a first reference point located therebetween in the first layer, but also have mirror symmetry to each other with respect to the first reference point,
wherein the two pairs of hollowed feature are designed to be in the form of two pairs of through-holes having rectangular sections in the second layer respectively, with the two imaginary lines connecting between geometric centers of respective pairs in the two pairs of through-holes extending in the two mutually orthogonal directions respectively,
wherein the pair of solid features are at least partially observable through one pair of through-holes, which functions as the respective pair of hollowed features and have its respective imaginary line connecting between geometric centers thereof extending in a first direction of the two mutually orthogonal directions, and the other pair of through-holes not only have central symmetry about a second reference point in the second layer but also have mirror symmetry to each other with respect to the second reference point, and
wherein respective two opposite side edges of the strip-shaped sections of the pair of solid features extend in a second direction, perpendicular to the first direction, of the two mutually orthogonal directions and are at least partially exposed from the respective pair of hollowed features.