Major IC packager reports elimination of formation of oxide on exposed Al/Cu bond pads during dicing through implementation of TENSOR HTD coolant water additive.
TENSOR HTD is a chemical formulation which when added to coolant water during dicing (singulation) greatly reduces or eliminates the formation of aluminum oxide on the surface of exposed Al/Cu bond pads and interconnects.
With the introduction of larger wafers combined with the increase in the amount of die per wafer, interconnect structures are exposed to coolant water for longer periods of time during the dicing process. It is during this extended exposure corrosion due to electrolytic/galvanic reactions occurs. Subsequent oxide formation occurs that measures thicker than 25 Angstroms (auger analysis). Thicker oxide formation results in poor bonding during packaging and resultant device failure.
A major IC packager reported recently that by simply injecting TENSOR HTD to the dicing saw coolant water at a ratio of 200:1, oxide formation was eliminated. Prior to using TENSOR HTD, the exposed metal interconnect structures would form an oxide layer of >75angstroms. This caused bonding problems and excessive scrap costs not tolerable to their customer. Once the product was implemented at the packagerís facility, scrap costs attributed to bond failure were significantly reduced.
The packager also reported that other benefits from using TENSOR HTD included; cleaner dicing blades that produce less chipping, reduction in the build-up of silicon dust on the wafer surface and elimination of the need for CO2 injectors used to reduce electrostatic discharge (ESD).