Specific Process Knowledge/Thin film deposition/Electroplating-Ni: Difference between revisions
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== Technotrans microform.200 == | == Technotrans microform.200 == | ||
The Technotrans microform.200 (Electroplating-Ni in LabManager) is a machine capable of depositing nickel electrochemically. This is done by lowering the sample into an electrolyte containing nickel ions and | The Technotrans microform.200 (Electroplating-Ni in LabManager) is a machine capable of depositing nickel electrochemically. This is done by lowering the sample into an electrolyte containing nickel ions and then apply a voltage across the sample and the anode. The anode is a basket filled with nickel pellets. The cathode is the sample to be coated with nickel. | ||
At the anode metallic nickel is oxidized to nickel ions: | |||
Ni (s) Ni2+ (aq) + 2 e- | |||
At the cathode (the sample surface), nickel ions from solution are reduced to metallic nickel: | |||
Ni2+ (aq) + 2 e- Ni (s) | |||
The minimal charge accepted by the software on the machine is 0.1 Ah (Ampere-hours). This corresponds to roughly 2 µm of nickel on a four inch wafer. You can abort a program prematurely to achieve even lower thicknesses, but this requires manual control of the machine. | |||
The maximum allowed thickness is ~1,4 mm (1400 µm), since higher a thickness will make the release of the sample difficult. This corresponds to a charge of 53-54 Ah on a four inch wafer. | |||
The plating bath is an aqueous solution of nickel sulphamate, boric acid and sulfamic acid. The bath is moderately acidic (pH = 3,5 - 3,8) and the temperature of the bath is 51-52°C. The sample will spin at 60 RPM during deposition. | |||
Uniformity across a 4" wafer is around 5% for the standard processes (the edge being slightly thicker than the center of the sample). Running at high current densities will deposit a nickel layer that is quite soft. Decreasing current density will increase tensile strength of the deposited nickel. | |||
'''The user manual(s), quality control procedure(s) and results, user APV(s), technical information and contact information can be found in LabManager:''' | '''The user manual(s), quality control procedure(s) and results, user APV(s), technical information and contact information can be found in LabManager:''' | ||