Metallization of Electronic Interconnects (HDI and ULSI) by Charge Modulation Control of Metal Distribution

摘要

A charge-modulated electrochemical deposition (CM-ECD) process is being developed to meet the specifications of today's advanced interconnect structures, such as ultra large scale integration (ULSI) and high density interconnect (HDI) for the semiconductor and printed wiring board industries, respectively. The key technical objectives of the CM-ECD process are to obtain void-free copper metallization, either conformal or feature filling, and minimal over-plate. By proper tuning of the CM-ECD process parameters, specifically cathodic and anodic on-times and peak currents, the above objectives can be met for interconnect sizes of 0.25 to 325 microns. In addition, the CM-ECD process utilizes a simple plating bath chemistry and multiple interconnect sizes are plated by sequencing the CM-ECD process parameters. Consequently, the need for masking and/or changing a proprietary plating bath chemistry is eliminated.