July 17, 2007 – A new system for ultrathin wafer processing developed by Brewer Science Inc. and EV Group aims to provide a temporary wafer bonding technology for reliably processing sub-100-micron thinned wafers.
The jointly developed technology, combining Brewer’s WaferBOND HT series of materials and EV Group’s bonding and debonding equipment platforms (EVG 850TBDB), performs temporary bonding of original-thickness device wafers onto rigid carrier wafers. The WaferBOND HT materials are spin-coated on, baked, and bonded on the EVG system, preparing for thinning and further backside processing steps with the created waferstack, the companies said.
Meanwhile, at SEMICON West, Brewer says it has commercialized its first-generation WaferBOND HT-250 coating, targeting higher-temperature advanced processes for flash memory, image sensors, and power devices. The polymeric spin-on coating enables device substrates to be temporarily bonded to a carrier substrate for thinning and follow-on processes, such as deposition, lithography, etching, plating, annealing and cleaning, to generate through-hole via structures and redistribution layers on the thin device wafer, the company says.
Brewer says the material has processing capability >200 deg.C with “broad” chemical resistance and process capability, low total thickness variation (<0.5-microns at 10nm), "excellent edge protection," <5mins slide-off debonding cycle, and "easy" polar solvent cleanup.
IMAGE CAPTION: Wafer with 0.7