A 3DStacked MemoryIntegrated onaLogicDevice UsingSMAFTITechnology

A general-purpose 3D-LSIplatform technology fora high-capacity stacked memoryintegrated onalogic device wasdeveloped forhigh-performance, power-efficient, and scalable computing. SMAFTItechnology [1-5], featuring an ultra-thin organic interposer withhigh-density feedthrough conductive vias, wasintroduced forinterconnecting the3D stacked memoryandthelogic device. A DRAM-compatible manufacturing process wasrealized through theuseofa"viafirst" process andhighly dopedpoly-Si through-silicon-vias (TSVs) forvertical traces inside memorydice. A multilayer ultra-thin die stacking processusingmicro-bump interconnection technology wasdeveloped, andSn-Ag/Cu pillar bumpsandAu/Nibackside bumpsformemorydice wereusedforthis technology. Thevertical integration of stacked DRAM withTSVsandalogic device inaBGA package hasbeensuccessfully achieved, andactual device operation hasbeendemonstrated forthefirst timeasa3DLSIwiththeDRAM introducing TSVsonthelogic device.