Via the wanting glass: Many advances in semiconductor know-how hinge on decreasing package deal sizes whereas incorporating added performance and extra environment friendly energy supply strategies. Current strategies of energy supply devour vital area on the wafer, resulting in elevated prices, bigger die sizes, and fewer transistors. Earlier this 12 months, Samsung Semiconductor introduced its analysis on a substitute for standard semiconductor energy supply strategies: bottom energy supply. This might result in vital reductions in die measurement and decreased routing congestion.
In response to a report from TheElec and Samsung’s presentation at this 12 months’s Very Giant Scale Integration (VLSI) Symposium, the semiconductor producer used new bottom energy supply community (BS-PDN) approaches to efficiently cut back the required wafer space by 14.8% when in comparison with conventional entrance aspect energy supply networks (PDNs).
The profitable implementation additionally yielded 10.6% and 19% space reductions in two ARM circuits whereas decreasing wiring size by 9.2%.
In conventional frontside PDNs (FSPDNs), semiconductor parts should be organized on the entrance aspect of the wafer to be able to present transmission from the facility line to the sign line and to the transistors.
This configuration requires shared area and assets between the supply and sign networks, more and more resistant routing to hold electrons throughout the back-end-of-line stack, and may end up in power loss throughout transmission to floor rails within the semiconductor construction.
BS-PDN (Bottom Energy Supply Community) is designed to handle these architectural and energy supply limitations. The method utterly decouples the facility supply and sign networks and makes use of the bottom of the wafer to accommodate energy distribution. Utilizing the bottom of the wafer, Samsung and different semiconductor producers can as a substitute direct energy supply by shorter, wider strains that provide much less resistance, improved energy supply efficiency, and lowered routing congestion.
Whereas the transfer from FSPDN to BS-PDN sounds promising, there are a number of challenges that stop it from turning into a typical method for producers pursuing the know-how.
One of many greatest challenges to implementing the brand new energy supply mannequin, additionally introduced by Samsung on the symposium, is the potential discount in tensile energy related to BS-PDN. When utilized, BS-PDN can cut back the tensile stress acts and through-silicon through electrode (TSV), leading to separation from the steel layer.
Samsung mentioned that this drawback will be solved by decreasing the peak or widening the TSV, nevertheless extra analysis and testing is required earlier than an answer will be formally introduced. Further advances in sign and energy line connectivity may also be required to efficiently apply BS-PDN.
Along with the above, advances in chemical mechanical sharpening (CMP) know-how would even be required. Present CMP implementations are used to take away 5 to 10 microns of “peaks and valleys” from the bottom of a wafer. Implementing BS-PDN might require a brand new solution to polish the wafer with out damaging the underlying energy parts.
Samsung doesn’t have a present timeline outlining official implementation of BS-PDN-based architectures, however primarily based on present findings and challenges, it is not but clear if we’ll see BS-PDN implementations from Samsung, or different producers like TSMC and Intel, for a number of extra years.
Picture supply: imec-int.com
