Samsung is a leading memory manufacturer and it has now announced a technology that will make it possible for them to stack memory circuits. Samsung has used the “through silicon via” (TSV) technology to stack four 512MBit DDR2 circuits on top of each other to create a “wafer-level-processed stacked package” (WSP) at 2Gbit. IBM has announced that it has used the same technology to build three dimensional circuits. In the long run TSV will make it possible for Samsung to build single modules with up to 4GB capacity. The secret is to replace the wires between the circuits. Using lasers they cut through the silicon and fill the gap with copper and then place them on top of each other.
Samsung has managed to work around the performance issues that have surfaced with previous processes by housing the WSP in aluminum. All in all this is a pretty advanced process which we suspect will be reflected by the price of the modules.