Scalable selective-area diamond growth for thermal management applications

Abstract

Selective-area growth of diamond is highly desirable for integrated electronics and thermal management, yet scalable patterning with controlled microstructure remains challenging. Here, we report a nucleation-engineered strategy for selective-area and wafer-scale diamond growth using microwave plasma chemical vapor deposition. By combining nanodiamond seeding with either conventional photolithography or a laser-defined peel-off masking process, diamond patterns are realized across length scales ranging from micrometers to full 2-in. wafers on Si and GaN substrates. We demonstrate that spatial variations in seeding density result in distinct growth regimes, producing fine-grained diamond with mixed orientations in densely seeded regions and large-grained, (111)-textured diamond in sparsely seeded regions through geometric and thermodynamic selection. The resulting patterned diamond films exhibit high crystalline quality, as confirmed by Raman spectroscopy and x-ray diffraction. As a proof-of-concept demonstration, selectively patterned diamond films are employed as heat spreaders on Si substrates, resulting in an operating temperature reduction of more than 23 °C compared to bare Si under identical electrical loading conditions. These results establish scalable selective-area diamond growth as an effective platform for microstructured thermal management and integrated device applications.