Ion-implantation in bulk semi-insulating 4H–SiC

Abstract

Articles you may be interested inLattice mismatch and crystallographic tilt induced by high-dose ion-implantation into 4H-SiC Effects of implantation temperature on damage accumulation in Al-implanted 4H-SiC J. Appl. Phys. 95, 4012 (2004); 10.1063/1.1666974 High-energy (MeV) Al and B ion implantations into 4H-SiC and fabrication of pin diodes Comparison of the annealing behavior of high-dose nitrogen-, aluminum-, and boron-implanted 4H-SiC Appl.Multiple energy N ͑at 500°C͒ and Al ͑at 800°C͒ ion implantations were performed into bulk semi-insulating 4H-SiC at various doses to obtain uniform implant concentrations in the range 1 ϫ10 18 -1ϫ10 20 cm Ϫ3 to a depth of 1.0 m. Implant anneals were performed at 1400, 1500, and 1600°C for 15 min. For both N and Al implants, the carrier concentration measured at room temperature for implant concentrations р10 19 cm Ϫ3 is limited by carrier ionization energies, whereas for the 10 20 cm Ϫ3 implant, the carrier concentration is also limited by factors such as the solubility limit of the implanted nitrogen and residual implant damage. Lattice quality of the as-implanted and annealed material was evaluated by Rutherford backscattering spectroscopy measurements. Residual lattice damage was observed in the implanted material even after high temperature annealing. Atomic force microscopy revealed increasing deterioration in surface morphology ͑due to the evaporation of Si containing species͒ with increasing annealing temperature. The surface damage is in the form of long furrows running in one direction across the wafer to a depth of ϳ25 nm from the surface for samples annealed at 1600°C for 15 min. We measured room temperature sheet resistivities of ϳ70 and 1.2ϫ10 4 ⍀/sq., respectively, for 2ϫ10 19 cm Ϫ3 N ͑1500°C annealing͒ and 1ϫ10 20 cm Ϫ3 Al ͑1600°C annealing͒ implanted samples.

Comparison of Solid-State Microwave Annealing with Conventional Furnace Annealing of Ion-Implanted SiC

“…8,24 On the other hand, the boron implant is known to redistribute in SiC even for low-temperature annealing. 14,25 The small atomic size of boron resulting in a high transient enhanced diffusion is believed to be responsible for this behavior. In this work, we have performed SIMS measurements to study boron implant depth profiles in microwave-annealed SiC.…”

“…It is well known that due to a high donor ionization energy (%70-80 meV) in SiC, the measured carrier concentration at RT does not represent the actual substitutional activation of the implant. 25 By comparing the results of rapid SSM with that of furnace annealing for the 15-280 keV multiple energy N + implant, it can be stated that the implantation temperature plays an important role in the dopant activation process of rapid SSM annealing. For a 1620°C/10 s SSM annealing, the sheet resistance is closer to that of furnace annealing for the elevated temperature implantation, whereas it is only 50% of the corresponding furnace annealing value for the RT implantation.…”

Deep Level Defects in Silicon Carbide

“…Nj-Na at T = 300 K (1) and T = 650 K (2), difference of these(3), and concentration of the center at E c -1.1-1.22 eV(4)vs. the irradiation dose. From ref.…”

Ultra-Fast Microwave Heating for Large Bandgap Semiconductor Processing

“…5(a)). These furrows are supposed to be caused by the thermal desorption of species such as Si, SiC 2 , Si 2 C, etc, a mechanism which is popularly known as 'step bunching' (Capano et al, 1999;Rao et al, 1999;Vathulya and White, 2000;Rambach et al, 2005). The step bunching puts fabrication constraints on SiC devices (Phelps et al, 2002).…”