Papers by Keyword: PVT Method

Abstract: The development of semiconductor materials and devices will lead to a new industrial technology revolution, in which the Silicon Carbide (SiC) substrate material has very excellent performance and it is especially suitable for manufacturing wave length lasers, white light emitting tubes, high-frequency, high-temperature and high-power devices, etc. This paper focuses on solving the key problems for producing large size and low defects of SiC crystals by the PVT method, such as the preparation and purification of the high purity raw material, the simulation of the temperature field, the control of the crystal defects and the growth of the large size SiC crystals.It is critical for the development of SiC industry.

Abstract: Several SiC bulk crystals were grown with erbium and ytterbium as doping materials. Erbium contents determined by secondary ion mass spectroscopy (SIMS) ranged from 1.2 · 1014 cm-3 to 1.04 · 1015 cm-3, while ytterbium contents were below SIMS detection limit. Photoluminescence (PL) investigations of the characteristic 4f-4f-transition lines revealed a reduced luminescence yield in highly nitrogen and aluminum co-doped samples. Also, samples without intentional co-doping grown on the C-face showed less luminescence intensity than those grown on the Si-face. A stabilizing effect of erbium doping on the 4H polytype was observed.

Abstract: Several highly aluminum doped SiC bulk crystals were grown with a modified PVT (MPVT) method. To facilitate 4H-SiC formation, growth was conducted on the C-face. The samples were investigated using Hall measurements in the Van-der-Pauw geometry. Lowest room temperature values for specific resistivities were 0.09 Ωcm for 6H-SiC and 0.2 Ωcm for 4H-SiC, which are to our knowledge the lowest values yet reported in literature. Thus, resistivity values of < 0.2 Ωcm, which are required for substrates in high power device applications, could be demonstrated for 4HSiC. Remarkably, in very highly doped samples the type of conduction could not be determined by Hall measurements.