Memory device including a word line with portions with different sizes in different metal layers

A memory device, comprising:

• a first word line configured to transmit a first word line signal to a first set of memory cells arranged in a first row;
• a second word line configured to transmit a second word line signal to a second set of memory cells arranged in a second row, wherein a first portion of the second word line is formed in a first metal layer, a second portion of the second word line is formed in a second metal layer, a third portion of the second word line is formed in a third metal layer above the second metal layer, and fourth portions of the second word line are formed in a fourth metal layer;
• a third word line configured to transmit a third word line signal to a third set of memory cells arranged in a third row;
• and
• a fourth word line configured to transmit a fourth word line signal to a fourth set of memory cells arranged in a fourth row
• wherein the fourth portions of the second word line are partially overlapped with the second portion of the second word line, and the third portion of the second word line, in a layout view.

A memory device, comprising:

• a first segment of a first word line and a first segment of a second word line formed in a first metal layer;
• a second segment of the first word line and second segments of the second word line formed in a second metal layer above the first metal layer;
• third segments of the second word line formed in a third metal layer between the second metal layer and a fourth metal layer that is above the second metal layer;
• and
• a third segment of the first word line formed in a fifth metal layer,
• wherein the third segment of the first word line and the first segment of the first word line are overlapped by the second segment of the first word line entirely.