GlobalFoundries: Enhancing the accuracy of 3D-xACT for F2F 3D IC

Face-to-face (F2F) bonded 3D IC design is a fine-pitch vertical integration technique in which two active dies are directly bonded at their front-side metal layers. Effective 3D IC design requires co-optimization across architecture, physical design, packaging, and reliability domains, supported by specialized electronic design automation (EDA) tools and cross-die verification strategies. One such area of interest is the interface capacitance extraction between the dies. Traditionally, the Calibre 3D-xACT was targeted at Chiplets based digital design and was extracting (and netlisting between the ports) the interface capacitance of the nets connected to the ports only.

For more accurate characterization for high frequency AMS/RF the internal nets and the distributed capacitance are needed. Also, the net names and sub-net names of the parasitics need to be exactly matching the individual die parasitic netlist. We worked with Siemens PEX team to generate more detailed parasitic information using Calibre 3D-xACT for AMS/RF Designs.

Here is the brief on the new flow. The individual PEX tools are enhanced to insert additional ports during individual dies extraction and to generate (using the Calibre 3D STACK) annotated assembly design in GDS or OASIS format, as well as 3D LVS of the interface . This assembly layout has all the internal nets and sub-net information with same name as individual die parasitic netlist. Using this assembly layout, the interface capacitance is calculated using the Calibre 3D-xACT tool, generating detailed parasitics for AMS/RF design characterization.