Lateral electrodeposition of compositionally modulated metal layers
View Patent ↗A method for making a laterally modulated metallic structure that is compositionally modulated in the lateral direction with respect to a substrate.
1. A method for forming a laterally modulated metallic structure comprising:
forming a pattern in a masking material situated on a first metal layer to form an exposed region of the first metal layer;
etching the exposed region of the first metal layer to expose a substantially nonconductive substrate;
etching the first metal layer between the masking material and the substantially nonconductive substrate for a distance to form a cavity comprising a first metal sidewall and an underside of the masking material; and
electrochemically depositing a second metal layer on the first metal sidewall, the second metal layer comprising one or more metals, wherein the second metal layer is deposited in a sideways direction from the first metal sidewall.
2. The method of claim 1 , wherein at least one of the one or more metals differs from a metal of the first metal layer.
3. The method of claim 1 , wherein the step of etching is a cathodic etching step.
4. The method of claim 1 , wherein the step of electrochemically depositing uses a time-varying potential.
5. The method of claim 4 , wherein the time-varying potential is a pulsed potential.
6. The method of claim 1 , wherein the step of electrochemically depositing uses a periodically varying potential.
7. The method of claim 1 , wherein the second metal layer comprises alternating layers of ferromagnetic metal and nonferromagnetic metal.
8. The method of claim 1 , further comprising removing the masking material after the step of electrochemically depositing.
9. The method of claim 1 , wherein the first metal layer is selected from the group consisting of Cu, a copper alloy, Ni, a Ni alloy, Ag, a Ag alloy, Au, a Au alloy, Co, and a Co alloy.
10. The method of claim 1 , wherein the one or more metals of the second metal layer are selected from the group consisting of Cu, a copper alloy, Ni, a Ni alloy, Ag, a Ag alloy, Au, a Au alloy, Co, and a Co alloy.
11. The method of claim 1 , further comprising removing a portion of the substantially nonconductive substrate.