Thermal management is critical in modern electronic systems. Efforts to improve heat dissipation have led to the exploration of novel semiconductor materials with high thermal conductivity, including boron arsenide (BAs) and boron phosphide (BP). However, the integration of such materials into devices and the measurement of their interface energy transport remain unexplored. Here, we show that BAs and BP cooling substrates can be heterogeneously integrated with metals, a wide-bandgap semiconductor (gallium nitride, GaN) and high-electron-mobility transistor devices. GaN-on-BAs structures exhibit a high thermal boundary conductance of 250 MW m⁻² K⁻¹, and comparison of device-level hot-spot temperatures with length-dependent scaling (from 100 μm to 100 nm) shows that the power cooling performance of BAs exceeds that of reported diamond devices. Furthermore, operating AlGaN/GaN high-electron-mobility transistors with BAs cooling substrates exhibit substantially lower hot-spot temperatures than diamond and silicon carbide at the same transistor power density, illustrating their potential for use in the thermal management of radiofrequency electronics. We attribute the high thermal management performance of BAs and BP to their unique phonon band structures and interface matching.

热管理在现代电子系统中至关重要。改善散热的努力导致了对具有高导热性的新型半导体材料的探索，包括砷化硼（BAs）和磷化硼（BP）。然而，将这些材料集成到设备中以及测量它们的界面能量传输仍未得到探索。在这里，我们展示了 BA 和 BP 冷却基板可以与金属、宽带隙半导体（氮化镓，GaN）和高电子迁移率晶体管器件异质集成。^{GaN-on-BAs 结构表现出 250 MW m -2}  K ^-1的高热边界电导，以及器件级热点温度与长度相关缩放（从 100 μm 到 100 nm）的比较表明，BA 的功率冷却性能超过了报道的金刚石器件。此外，在相同的晶体管功率密度下，使用 BAs 冷却基板运行的 AlGaN/GaN 高电子迁移率晶体管的热点温度显着低于金刚石和碳化硅，这说明了它们在射频电子器件热管理中的应用潜力。我们将 BA 和 BP 的高热管理性能归因于它们独特的声子能带结构和界面匹配。