Silicon Wafers /
CMOS-compatible UBM for Silicon Wafers / SOI Wafers
These under bump metallization steps
produce optimum results on silicon wafers /
CMOS-COMPATIBLE PROCESS FOR
Cleaner – Epithas MCL—067 acid soak cleaner
for pretreatment of silicon wafers, including SOI wafers, prior to the Epithas Ni/Au process.
Micro-etch – LEC-19 removes naturally-occurring oxidation from aluminum and aluminum alloy surfaces. Pretreatment for electroless nickel on aluminum for silicon wafers, including SOI wafers.
Zincate – MCS-30 acid immersion zinc for silicon wafer plating; minimizes the dissolution of aluminum, assures thin, uniform zinc deposit for subsequent electroless nickel plating.
Electroless Nickel – NPR-18CM was developed for wafer plating applications with fine line circuitry. Highly stable bath; allows bridge-free deposition of electroless nickel. Low temperature operation for improved resist tolerance. 6-8% phosphorus as plated. 100 hour salt spray performance (ASTM B117). Adhesion is superior to electroplated nickel.
CMOS COMPATIBLE PROCESS FOR
Cleaner – Epithas MCL—067 acid soak pretreatment for silicon wafer plating,
including SOI wafers
Activator – MCT-14 is a highly stable activator for copper and copper alloys. Immersion reaction bath deposits palladium only on the copper surface. The palladium initiates the subsequent autocatalytic nickel plating step, electroless nickel.
Electroless Nickel – NPR-18CM – for wafer plating, including SOI wafers, involving fine line circuitry.