Uniform crack-free aluminum deposition by two step aluminum electroplating process
In one implementation, a method of depositing a material on a substrate is provided. The method comprises positioning an aluminum-containing substrate in an electroplating solution, the electroplating solution comprising a non-aqueous solvent and a deposition precursor. The method further comprises depositing a coating on the aluminum-containing substrate, the coating comprising aluminum or aluminum oxide. Depositing the coating comprises applying a first current for a first time-period to nucleate a surface of the aluminum-containing substrate and applying a second current for a second time-period, wherein the first current is greater than the second current and the first time-period is less than the second time-period to form the coating on the nucleated surface of the aluminum-containing substrate.
1. A method of depositing a material on a substrate, comprising:
positioning an aluminum-containing substrate in an electroplating solution, the electroplating solution comprising a non-aqueous solvent and a deposition precursor;
depositing a coating on the aluminum-containing substrate, the coating comprising aluminum or aluminum oxide, wherein depositing the coating comprises:
applying a first current for a first time-period to nucleate a surface of the aluminum-containing substrate; and
applying a second current for a second time-period, wherein the first current is greater than the second current and the first time-period is less than the second time-period to form the coating on the nucleated surface of the aluminum-containing substrate;
wherein the first current is between about −150 milliamperes (mA) and about −60 mA and the second current is between about −50 mA and about −30 mA; and
wherein the first time-period is between about 60 seconds and about 300 seconds and the second time-period is between about 20 minutes and about 5 hours.
2. The method of claim 1 , wherein the electroplating solution comprises the non-aqueous solvent and a second solvent in a ratio of between 4:1 and 1:4.
3. The method of claim 1 , wherein the aluminum substrate comprises Al6061 or Al6063 alloy.
4. The method of claim 1 , wherein the deposition precursor comprises AlCl 3 or Al(NO 3 ) 3 .
5. The method of claim 4 , wherein the deposition precursor has a concentration within a range of about 0.3 M to about 1 M.
6. The method of claim 1 , wherein the electroplating solution further comprises a supporting electrolyte.
7. The method of claim 6 , wherein the deposition precursor has a concentration within a range of about 0.1 M to about 0.3 M.
8. The method of claim 1 , wherein depositing the coating comprises pulsing the first current on and off.
9. The method of claim 1 , wherein the coating has a thickness of between about 100 nanometers to about 2 micrometers.
10. A method of depositing a material on a substrate, comprising:
positioning an aluminum-containing substrate having one or more plenums formed therein in an electroplating solution, the electroplating solution comprising:
a deposition precursor comprising AlCl 3 , Al(NO 3 ) 3 , or an aluminum alkyl; and
a non-aqueous solvent; and
depositing a coating on the aluminum-containing substrate, the coating comprising aluminum or aluminum oxide, wherein depositing the coating comprises:
applying a first current for a first time-period to nucleate a surface of the aluminum-containing substrate, wherein the first current is pulsed; and
applying a second current for a second time-period, wherein the first current is greater than the second current and the first time-period is less than the second time-period to form the coating on the nucleated surface of the aluminum-containing substrate;
wherein the first time-period is between about 60 seconds and about 300 seconds and the second time-period is between about 20 minutes and about 5 hours; and
wherein the first current is between about −150 milliamperes (mA) and about −60 mA and the second current is between about −50 mA and about −30 mA.
11. The method of claim 10 , wherein the first current is pulsed-on for a third time-period of between about 30 milliseconds and about 70 milliseconds and the first current is pulsed-off for a fourth time-period of between about 10 milliseconds and about 20 milliseconds.
12. The method of claim 10 , further comprising:
removing excess plating solution from the aluminum-containing substrate, wherein removing the excess plating solution comprises washing and drying the aluminum-containing substrate; and
post-treating the aluminum-containing substrate having the coating thereon.
13. The method of claim 12 , wherein the post-treating comprises exposing the aluminum-containing substrate to an ozone plasma.
14. A method of depositing a material on a substrate, comprising:
positioning an aluminum-containing substrate having one or more plenums formed therein in an electroplating solution, the electroplating solution comprising:
a deposition precursor comprising AlCl 3 , Al(NO 3 ) 3 , or an aluminum alkyl;
a non-aqueous solvent; and
a supporting electrolyte;
depositing a coating on the aluminum-containing substrate, the coating comprising aluminum or aluminum oxide, wherein depositing the coating comprises:
applying a first current for a first time-period to nucleate a surface of the aluminum-containing substrate, wherein the first current is pulsed; and
applying a second current for a second time-period, wherein the first current is greater than the second current and the first time-period is less than the second time-period to form the coating on the nucleated surface of the aluminum-containing substrate;
wherein the first time-period is between about 60 seconds and about 300 seconds and the second time-period is between about 20 minutes and about 5 hours; and
wherein the first current is between about −150 milliamperes (mA) and about −60 mA and the second current is between about −50 mA and about −30 mA.