Element Six and Entegris develop diamond chip cooling

Element Six and Entegris have established a long-term development partnership to integrate synthetic diamond into advanced semiconductor packaging, with engineering work focused on wafer-level bonding, surface preparation, and the thermal resistance between diamond and surrounding materials.

The agreement combines Element Six’s expertise in engineered synthetic diamond with Entegris’ semiconductor materials and surface engineering capabilities. The companies intend to develop manufacturing approaches suitable for graphics processors, radiofrequency devices, and more complex semiconductor packages incorporating advanced logic and memory.

Both single-crystal and polycrystalline diamond are included in the programme, alongside engineered surfaces and bonded structures intended to accommodate different device architectures. The partners have not disclosed a qualified commercial process, customer deployment, or date for volume production.

Semiconductor thermal management becomes increasingly demanding as more processing resources are integrated into a limited package area. Graphics processors and other high-performance devices can generate concentrated regions of heat, while advanced packaging may place several active dies and memory components close together.

Heat must move from the semiconductor junction through a sequence of materials before reaching the external cooling system. These can include the semiconductor die, bonding materials, package substrates, heat spreaders, and thermal interfaces connecting the assembly to a heat sink or liquid cooling arrangement.

Each layer contributes resistance to heat flow, and the interfaces between dissimilar materials can introduce additional restrictions. A material with high thermal conductivity may therefore deliver a smaller improvement than expected if heat cannot pass efficiently into or out of it.

Synthetic diamond is attractive because its thermal conductivity can substantially exceed that of conventional heat-spreading metals. Element Six supplies chemical vapour deposition diamond materials with thermal conductivity values ranging from approximately 1,000 to 2,200 W/mK across its product grades.

Those values describe the bulk properties of particular diamond materials. Their contribution within a semiconductor package depends on thickness, geometry, orientation, interface quality, and the thermal characteristics of the surrounding components.

The problem becomes more complex where high-power devices contain several dies arranged side by side or stacked vertically. Heat generated in one region may need to pass through multiple interfaces and intermediate structures before it can be removed.

Thermal boundary resistance is particularly important at the junction between diamond and another material. Even where both materials conduct heat efficiently, an imperfect interface can impede the transfer of thermal energy.

Surface roughness, microscopic voids, contamination, and the composition of intermediate bonding layers all influence the effective resistance. Mechanical contact alone may not provide a sufficiently reliable or efficient thermal path for a high-power semiconductor package.

Element Six and Entegris intend to address these constraints through engineered diamond surfaces and bonding technologies. Their development programme covers manufacturing methods that can incorporate diamond at wafer level rather than relying exclusively on the attachment of separately processed heat spreaders after individual devices have been packaged.

Wafer-level integration could provide opportunities for more repeatable assembly and alignment, although its practicality depends on compatibility with semiconductor fabrication processes and the reliability of the completed bond.

Suitable bonding methods must accommodate the different mechanical and thermal properties of diamond and the adjoining semiconductor or package material. Temperature changes during fabrication and operation can generate stress where materials expand or contract at different rates.

Repeated thermal cycling may also influence bond integrity. Semiconductor qualification will therefore require measurements covering thermal performance, mechanical reliability, processing yield, and the behaviour of the interface over time.

The collaboration includes heterogeneous integration, where dies or materials manufactured using different processes are combined in a single assembly. This approach is increasingly used to integrate processing, memory, and specialised functions without manufacturing every component using the same semiconductor technology.

Such packages can introduce several concentrated heat sources and complex routes for heat removal. Diamond materials may offer additional thermal capacity within selected regions, but the optimum configuration will depend on the placement of active devices and the electrical and mechanical constraints of the package.

Element Six already manufactures synthetic diamond for thermal management applications, including heat spreaders and composite materials. The new partnership builds on that material capability by developing approaches intended for closer integration into semiconductor manufacturing.

Entegris contributes expertise in materials processing and surface engineering. Its existing semiconductor activities include materials used in polishing, cleaning, and other fabrication operations where surface characteristics and contamination control are important.

The company also completed its acquisition of Advanced Abrasives Corporation, a supplier of diamond-based precision abrasives used in hard-substrate polishing. Entegris is planning a new manufacturing line in Taiwan for silicon carbide processing solutions, alongside continued US research into advanced thermal interface materials.

Those developments form part of Entegris’ wider materials strategy. The Taiwan manufacturing investment concerns silicon carbide solutions and should not be presented as a confirmed production facility for the diamond structures being developed with Element Six.

Olivier Blachier, Chief Innovation Officer and President of Materials Solutions at Entegris, said the development work would concentrate on engineering diamond surfaces and bonding methods suited to semiconductor packaging, rather than relying solely on the material’s thermal properties.

Producing a reliable diamond interface at commercial scale will require the partners to establish suitable process conditions, material specifications, and quality control methods. The economics of integration will also depend on processing complexity, usable manufacturing yield, and the amount of diamond material required for each package.

The companies have not reported thermal resistance measurements for a jointly developed structure or demonstrated a quantified temperature reduction in a commercial GPU or RF package. Their agreement establishes the scope of the development programme rather than confirming that the intended thermal improvements have already been achieved.

Entegris is scheduled to discuss its advanced thermal management strategy at its Capital Markets Day on 9 November 2026. Subsequent qualification results and semiconductor customer programmes will determine how the partnership progresses towards commercially manufactured diamond-enabled packages.