Ion-implantation in bulk semi-insulating 4H{endash}SiC
- Department of Electrical and Computer Engineering, George Mason University, Fairfax, Virginia 22030 (United States)
- Department of Material Science and Engineering, Australian National University, Canberra ACT 0200 (Australia)
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
- Naval Research Laboratory, Washington, D.C. 20375 (United States)
Multiple energy N (at 500&hthinsp;{degree}C) and Al (at 800&hthinsp;{degree}C) ion implantations were performed into bulk semi-insulating 4H{endash}SiC at various doses to obtain uniform implant concentrations in the range 1{times}10{sup 18}{endash}1{times}10{sup 20}&hthinsp;cm{sup {minus}3} to a depth of 1.0 {mu}m. Implant anneals were performed at 1400, 1500, and 1600&hthinsp;{degree}C for 15 min. For both N and Al implants, the carrier concentration measured at room temperature for implant concentrations {le}10{sup 19}&hthinsp;cm{sup {minus}3} is limited by carrier ionization energies, whereas for the 10{sup 20}&hthinsp;cm{sup {minus}3} 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 species) 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 {approximately}25 nm from the surface for samples annealed at 1600&hthinsp;{degree}C for 15 min. We measured room temperature sheet resistivities of {approximately}70 and 1.2{times}10{sup 4}&hthinsp;{Omega}/sq., respectively, for 2{times}10{sup 19}&hthinsp;cm{sup {minus}3} N (1500&hthinsp;{degree}C annealing) and 1{times}10{sup 20}&hthinsp;cm{sup {minus}3} Al (1600&hthinsp;{degree}C annealing) implanted samples. {copyright} {ital 1999 American Institute of Physics.}
- OSTI ID:
- 354506
- Journal Information:
- Journal of Applied Physics, Vol. 86, Issue 2; Other Information: PBD: Jul 1999
- Country of Publication:
- United States
- Language:
- English
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