SiC's thermal conductivity, strength, and chemical stability make it ideal for the heat fluxes in 2.5D and 3D chip designs.
www.powerelectronicsnews.com, Sept. 17, 2025 –
Silicon carbide (SiC) is best known as the wide-bandgap material driving high-efficiency power electronics that support the green transition. Yet its potential reaches beyond power electronics. SiC’s exceptional thermal and mechanical properties are now opening new opportunities in advanced chip packaging—particularly as artificial intelligence (AI) workloads and 3D architectures push thermal limits.
As AI accelerators and 2.5D/3D chip stacks grow ever denser, heat removal has become a critical constraint. TSMC, the world’s leading semiconductor foundry, is responding with a bold shift toward 12-inch monocrystalline SiC substrates, whose thermal conductivity can reach ~500 W·m⁻¹·K⁻¹—far exceeding that of conventional ceramics such as alumina (Al₂O₃) or sapphire.
Developed in collaboration with partners and equipment suppliers, this initiative aims to replace traditional ceramic bases in applications ranging from AR (augmented reality) smart lenses to hyperscale data-center processors. In wearable lenses, dense electronics operate within a tiny enclosure near the eye, making precise thermal management essential for user safety and device stability.
TSMC’s decision to exit the gallium nitride (GaN) business and focus on new uses of SiC reflects both market pressures and a recalibration of its materials strategy. By leveraging SiC’s superior thermo-mechanical performance, the company aims to build a scalable platform for next-generation packaging.
While 12-inch SiC substrates used for thermal management do not require the ultra-low defect densities demanded by power MOSFETs or diodes, crystal integrity remains essential.
Micropipes, voids, and dislocations can disrupt heat flow, compromise mechanical strength, and impair surface flatness during grinding and chemical–mechanical polishing. At larger diameters, issues like bow and warp become increasingly critical, as they directly impact die-attach quality and yield in advanced packaging workflows. Since heat in SiC is primarily conducted by quantized lattice vibrations (phonons), any crystal imperfection—such as micropipes, voids, or dislocations—that scatters or obstructs these vibrations reduces thermal conductivity and can lead to localized hot spots. Consequently, the focus shifts from eliminating electrically active defects to ensuring uniform bulk density, minimal porosity, and high surface planarity—key prerequisites for reliable, high-volume manufacturing of SiC thermal substrates.
High thermal conductivity, mechanical strength, and resistance to thermal stress, plus chemical stability in harsh environments, make SiC ideal for the intense heat fluxes in 2.5D and 3D chip designs.
In 2.5D integration—chips are mounted side-by-side on a silicon or organic interposer; connections are short, fast, and power-efficient.
By contrast, in 3D integration, chips are stacked vertically with through-silicon vias (TSVs) or hybrid bonding, creating very high interconnect density.
Beyond passive heat spreading, SiC enables hybrid cooling, combining traditional substrates and exotic solutions such as diamond or liquid metals.
TSMC’s decision to exit GaN by 2027 will allow the company to redirect resources toward SiC. Scaling to 12-inch wafers offers potential cost advantages and may improve process uniformity (in terms of lower process-induced defects per unit area), although crystal defect density and challenges in slicing, planarization, and wafer flatness remain.
Once synonymous with power devices, SiC is now entering domains where thermal control is the bottleneck. TSMC is evaluating:
Together, these pathways could reshape the thermal backbone of AI accelerators and data-center chips.
Effective heat dissipation is a key differentiator in advanced semiconductor design. Diamond achieves very high thermal conductivity (~1,000-2,200 W·m⁻¹·K⁻¹) in high-purity form, while single-layer graphene can reach ~3,000-5,000 W·m⁻¹·K⁻¹; but both remain costly and difficult to scale. Alternatives, such as liquid metals, conductive gels, and microfluidic cooling, also show promise, although they too face trade-offs in terms of cost, manufacturability, and integration.
SiC, by contrast, offers a more practical compromise: good thermal performance, strong mechanical robustness, and a path toward scalable, mass-producible components.
TSMC brings decades of experience in 12-inch wafer production. Its existing infrastructure, process control, and packaging expertise allow it to treat SiC not just as a material upgrade, but as part of a broader platform strategy—accelerating deployment in AI and high-performance computing without reinventing the manufacturing wheel.
TSMC’s SiC roadmap unfolds in tandem with Intel’s efforts in backside power delivery and other thermal-power co-design techniques. These approaches underline a broader shift: thermal management is now integral to semiconductor innovation.
TSMC is doing more than improving heat dissipation—it is shaping a differentiated platform for AI and high-performance computing, positioning SiC as a cornerstone of future chip packaging.