Progress in Near-Equilibrium Ammonothermal (NEAT) Growth of GaN Substrates for GaN-on-GaN Semiconductor Devices

• DOI: 10.3390/cryst12081085
• Publication Date: 2022-08-04T00:52:01Z
• Authors: Tadao Hashimoto; Edward R. Letts; Daryl Key
• Keywords: Crystal (programming language)

This paper reviews the near-equilibrium ammonothermal (NEAT) growth of bulk gallium nitride (GaN) crystals and reports evaluation 2″ GaN substrates 100 mmbulk crystal grown in our pilot production reactor. Recent progress oxygen reduction enabled growing NEAT with lower residual oxygen, coloration, optical absorption. The concentration was approximately 2 × 1018 cm−2, absorption coefficient 1.3 cm−1 at 450 nm. Maps full-width half maximum (FWHM) X-ray diffraction rocking curveswere generated for finished wafers. curve maps confirmed high-quality uniform microstructure across entire surface substrates. average FWHM 50 best from recent batch 28 ± 4 arcsec 002 34 5 201 diffraction, an radius curvature 20 m. topography measured on both sides implied that density dislocations wasreduced by one order magnitude during growth. A typical substrate shows dislocation about 105 cm−2.