High-Quality Thick Single-Crystal Diamond for Next-Generation Electronics

High-Quality Thick Single-Crystal Diamond for Next-Generation Electronics

At Diasemi, we focus on enabling the next leap in high-power, high-frequency electronics through breakthroughs in single-crystal diamond growth and device technology. Thick diamond films are essential for power electronics, RF systems, quantum devices, and extreme thermal environments—but until recently, scalable high-quality growth remained a major barrier.

Traditional MPCVD processes encounter serious challenges: edge polycrystallization, thickness-dependent degradation, and a trade-off between quality and growth rate. Effective area often shrinks as thickness increases, and films above ~1.7 mm commonly exhibit broadened XRD rocking curves, signaling crystal deterioration. Moreover, almost no work has been able to produce multiple >7 mm, high-quality thick diamond wafers in a batch process.

Diasemi’s optimized MPCVD methodology overcomes these barriers. Using an improved closed-substrate holder, precise temperature control, and refined plasma chemistry, we have demonstrated batch production of seven high-quality diamond samples up to 4.5 mm thick—all with smooth surfaces, no polycrystalline rims, and stable crystallinity across the entire area. XRD FWHM values remained below 78 arcsec with deviations <7 arcsec, while Raman FWHM values were consistently under 2.1 cm⁻¹.

To validate device-grade performance, we fabricated hydrogen-terminated diamond FETs on these samples. The devices achieved current densities exceeding 90–107 mA/mm, on/off ratios up to 9.35×10⁹, and mobilities of 76–89 cm²/(V·s). Threshold voltages, leakage currents, and on-resistance demonstrated exceptional uniformity, confirming that the underlying diamond is highly homogeneous and suitable for advanced electronics.

These results highlight Diasemi’s ability to deliver reproducible, large-area, ultra-high-purity diamond wafers for next-generation device platforms. Our advances in crystal growth, material control, and device integration establish a scalable pathway toward high-performance diamond electronics—reducing production costs while enabling the extreme thermal, electrical, and reliability requirements of future semiconductor technologies.