Automated Endpoint Detection of Copper Electrodeposition in Through-Silicon Vias (TSVs)

Background Information: For 3D, and heterogeneous integration (HI) of microelectronics devices, void-free copper (Cu)-filled TSVs are a critical technology. Cu overburden or over-plating, typically resulting from excess Cu electroplating on the surface often included to overcome process marginality, requires subsequent removal steps, generally by chemical mechanical polishing (CMP).

In general, more overburden requires longer CMP resulting in a loss of throughput and a higher consumption of consumable chemistries and polishing pads. Utilizing current and voltage transient signatures during the electrochemical deposition, Sandia has developed and filed for patent protection on automated endpoint detection methods which indicate when deposition has reached the top of the TSV features. Automation software allows for increased process monitoring and control.

Terminating deposition based on electrical data features results in vias with minimal Cu overburden. By reducing the time-consuming processing steps and providing automated process control, this endpoint detection method has potential to greatly enhance microelectronics manufacturing.

Technology Highlights: Improves manufacturing repeatability. Improves throughput and decreases consumable costs Relatively geometry independent – minimizing setup time for large work-mix manufacturers Endpoint signals are relatively insensitive to chemical changes – allowing improved process marginality to changes in the plating electrolyte over time.

Potential Applications: Semiconductor manufacturers and packaging vendors High bandwidth memory manufacturers Advanced packaging suppliers Opportunity Description: SNL is seeking partners to further develop and commercialize the TSV endpoint detection. Licensing and technical support (paid by Licensee) are available. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.

Primary Point of Contact: David V. Wick Licensing Executive Sandia National Laboratories dvwick@sandia.gov Keywords: Through Silicon Via, Through Substrate Via, TSV, Through Glass Via, TGV, microelectronics, heterogenous integration, 3D integration, electronics packaging, interposer, integrated circuit packaging