Metal wires and methods for manufacturing the same
The present disclosure provides a metal wire and a method for manufacturing the same. The method for manufacturing the metal wire includes: forming a metal bar on a substrate; forming a mask above the metal bar, a width of the mask being smaller than a width of the metal bar, and 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 to a saturation state under a protection of the mask to form a metal wire, a width of the metal wire being smaller than the width of the mask. The above method can form the metal wire with a high thickness and a narrow line width.
1 . 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.
2 . The method according to claim 1 , wherein the sacrificial layer is made of a light-sensitive organic material, the groove is formed by photo-etching the sacrificial layer, and the sacrificial layer is removed by ashing.
3 . The method according to claim 1 , wherein the first section of the groove is in a shape of isosceles trapezoid.
4 . The method according to claim 1 , wherein filling the metal material in the groove comprises:
depositing the metal material on the sacrificial layer and in the groove;
forming a photoresist pattern covering the metal material in the groove and exposing the metal material outside the groove; and
perform etching under a protection of the photoresist pattern to remove the metal material outside the groove.
5 . The method according to claim 1 , wherein the mask has a second section perpendicular to the substrate in a width direction of the mask, and the second section is narrow at a top and wide at a bottom as a whole.
6 . The method according to claim 5 , wherein the second section of the mask is in a shape of isosceles trapezoid.
7 . The method according to claim 1 , wherein the substrate comprises a Cyclo Olefin Polymer (COP) optical material; and
an ashing barrier layer is formed on the substrate before forming the sacrificial layer on the substrate, and the sacrificial layer is formed on the ashing barrier layer.
8 . The method according to claim 7 , wherein the ashing barrier layer comprises silicon nitride or silicon oxide.
9 . The method according to claim 1 , wherein a metal seed layer is formed on the substrate before forming the sacrificial layer on the substrate, the sacrificial layer is formed on the metal seed layer, and the groove formed in the sacrificial layer exposes the metal seed layer; and
the metal material is filled in the groove by electroplating, and the metal material is not formed outside the groove.
10 . The method according to claim 9 , wherein in a process of wet etching the metal bar to form the metal wire, an exposed part of the metal seed layer is synchronously removed or not synchronously removed.
11 . The method according to claim 1 , wherein forming the metal bar on the substrate comprises:
forming a sacrificial layer on the substrate;
forming a first groove and a second groove in the sacrificial layer, the first groove and the second groove being separated from each other and arranged side by side; and
depositing a metal material, wherein the metal material formed above the sacrificial layer between the first groove and the second groove serves as the metal bar.
12 . The method according to claim 11 , wherein the sacrificial layer is made of a light-sensitive organic material, and the first groove and the second groove are formed by photo-etching the sacrificial layer.
13 . The method according to claim 11 , wherein a width of the first groove and/or the second groove is greater than or equal to 2 microns, and slopes of sidewalls of the first groove and/or the second groove are greater than or equal to 80 degrees and less than or equal to 90 degrees.
14 . The method according to claim 11 , wherein a hard mask is formed on the sacrificial layer before forming the first groove and the second groove, and the hard mask is formed with openings corresponding to the first groove and the second groove; and
the sacrificial layer is dry etched with the hard mask to form the first groove and the second groove in the sacrificial layer.
15 . The method according to claim 14 , wherein the hard mask is removed before depositing the metal material.
16 . The method according to claim 14 , wherein the hard mask comprises molybdenum, aluminum, indium tin oxide or indium gallium zinc oxide.
17 . A metal wire manufactured by the method for manufacturing the metal wire according to claim 1 .