Metal wires and methods for manufacturing the same

A method for manufacturing a metal wire, comprising:

• forming a structure to be etched on a substrate, wherein the structure to be etched comprises a metal bar on a substrate and
• a mask above the metal bar, a width of a surface of the mask in contact with the metal bar being smaller than a width of a surface of the metal bar in contact with the mask, a width of a surface of the metal bar in contact with the substrate being smaller than the width of the surface of the metal bar in contact with the mask, wherein an orthographic projection of the mask on the substrate is within an orthographic projection of the metal bar on the substrate;
• and
• wet etching the metal bar of the structure to be etched until an etching speed is lower than one third of an average speed of a stable etching stage under a protection of the mask, wherein when the etching speed is lower than one third of the average speed of the stable etching stage, a metal wire is formed, a width of the metal wire being smaller than the width of the mask;
• widths of the metal wire at different heights are the same, and a highest height of the metal wire is greater than each of the widths of the metal wire;
• wherein forming the metal bar on the substrate comprises:
• forming a sacrificial layer on the substrate, a groove being formed in the sacrificial layer;
• the groove has a first section perpendicular to the substrate in a width direction of the groove, and the first section is wide at a top and narrow at a bottom as a whole, wherein the width direction of the groove is parallel to the substrate;
• filling a metal material in the groove to form the metal bar;
• and
• removing the sacrificial layer;
• wherein a direction of the width of the surface of the metal bar is parallel to the substrate, a direction of the width of the mask is parallel to the substrate, a direction of the width of the metal wire is parallel to the substrate, and a direction of the height of the metal wire is perpendicular to the substrate.