Electroplating

From LNF Wiki
Revision as of 10:29, 16 March 2020 by Tonyes (talk | contribs)
Jump to navigation Jump to search

Electroplating is the deposition of conductive films on conductive surfaces. Ideal to obtain thick conductive deposits at fast deposition rates.

Electroplating
Electrochemistry1.jpg
Electrochemical Cell
Technology Details
Other Names Electrodeposition, Electrochemical deposition
Technology Deposition
Equipment Gold Plating Bench, Acid Bench 92, Base Bench 91
Materials Au, Cu, Ni, In, Fe-Ni, Ag,
Warning Warning: This page has not been released yet.

Equipment

At this bench we offer Copper, Nickel, Indium, and Ni-Fe plating

At this bench we offer silver plating

Method of operation

Electroplating (also referred to as electrodeposition or electrochemical deposition) uses an electrical current to reduce a metal, M, in solution (called electrolyte) at the anode (negative electrode in a cell) turning the metal ions into solid metal. If the surface has a seed layer and it is patterned, the metal will only deposit into the patterned region, where the conductive seed layer is exposed. In the electro-deposition of metals, generally a metal ion Mz+ is transferred from the solution into the metal lattice of the electrode. This is accompanied by the transfer of z electrons from an outside source (power supply) to the metal to render Mo on the electrode. The addition of the metal onto the electrode follows several ion-transfer mechanism, which might produce different types of growth, depending on activation and final energies. Electroplating does not always produces uniform smooth surfaces. The use of chemicals, known as additives, that inhibit the columnar or dendritic growth, brighteners or leveling compounds are common in commercially available plating solutions. Other technique to improve or control the uniformity of the deposit are the use of pulse plating the optimization of the cell design.

Applications

Electroplating is generally used in the semiconductor industry to deposit films thicker than one micron. Evaporating or sputtering thicker than a micron thin films is wasteful and requires repeated equipment maintenance. Electroplating can also be used to deposit metal compounds, like the NiFe alloy. Electroplating is the recommended when depositing conductive compounds on that are off-the-line-of-sight, as the case of filling wafer-through via or filling pores in an aluminum oxide film (AAO).

Electroplating is commonly used to deposit metals and conductive polymers whose electrochemical potential is less cathodic than that of water. Though some metal electroplating, i.e. Pt, does use organic electrolyte, there not as common and easy to use as those that use aqueous electrolyte.

Figures of Merit

  • film thickness
  • film roughness
  • film stress
  • general uniformity
  • film chemical composition
  • deposition rate

See also

Further Reading

[1]

  • "Modern Electroplating" I. Schlesinger, Mordechay. II. Paunovic, Millan