Breakthrough in ‘bottom-up’ diamond patterning bypasses cutting or etching

As electronics become increasingly smaller and more powerful, driven by artificial intelligence development, they generate excessive, performance-hindering heat. Because of its high thermal conductivity, among other qualities, diamond has emerged as an ideal advanced electronics materials platform, but integrating it into chips has proven a major manufacturing challenge.

“Top-down” diamond patterning methods, such as reactive ion etching, are difficult given the material’s chemical inertness. While “bottom-up” approaches avoid the need for etching, they have historically faced challenges regarding scalability and masking materials.

Zhang et al. used microwave plasma chemical vapor deposition to develop a nucleation-engineered strategy for selective-area and wafer-scale diamond growth that provides for both precision and scalability.

“We can grow high-quality diamond exactly where we want it, from tiny microscopic patterns to full wafer scales on silicon and gallium nitride substrates,” said author Xiang Zhang. “Moreover, we found that patterning the diamond into small, specific islands actually cooled the electronics more effectively than covering the whole surface with a continuous film.”

Using a novel laser-defined masking strategy, the researchers patterned diamond on two-inch wafers. They also demonstrated the method’s high precision by replicating the shape of an owl (Rice University’s mascot) that preserved features as small as a few micrometers. Additionally, by changing nanodiamond placement density, they found they could tune the crystal structure, with sparser seeding generating larger, naturally preferred crystals.

“By enabling selective growth, we can place diamond heat spreaders directly onto active device regions — like the hot spots in high-power transistors — without damaging the surrounding material,” said Zhang. “This could lead to more efficient, cooler-running devices in everything from high-frequency communications to power electronics.”

Source: “Scalable selective-area diamond growth for thermal management applications,” by Xiang Zhang, Cheng Chang, Qing Zhu, Shisong Luo, Robert Vajtai, Yuji Zhao, and Pulickel M. Ajayan, Applied Physics Letters (2026). The article can be accessed at https://doi.org/10.1063/5.0319930 .

This paper is part of the Thermal Properties of Graphene and Carbon Materials — From Physics to Applications in Thermal Management Collection, learn more here .