For decades, transistor density has increased rapidly, but heat has become a major barrier to improving chip performance. The main reason is the end of Dennard scaling, which once allowed voltage and power to shrink as transistors got smaller. Now, even though transistor density continues to rise, power density and therefore heat rises too. This creates reliability issues, reduces efficiency, and risks thermal runaway in large systems such as data centers. Emerging transistor technologies, like nanosheets and CFETs, further increase power density, intensifying the thermal challenge. Cooling methods such as liquid cooling, immersion, microfluidics, and jet impingement offer improvements but are not sufficient on their own, especially in mobile devices and large data centers. A promising direction is backside technology moving power delivery, capacitors, and voltage regulators to the wafer’s underside. This can reduce voltage loss and lower heat generation, but thinning the silicon substrate introduces new hot-spot problems. Future chip design will require a holistic approach called system technology co-optimization, which integrates semiconductor processes, architecture, packaging, and cooling. No single solution will solve the heat problem; instead, advanced modeling, collaboration, and careful design choices will be essential to managing thermal limits in upcoming chip generations.
Read more-https://spectrum.ieee.org/hot-chips