12-12-2012, 12:44 PM
DOPING DEPENDENCE OF THERMAL OXIDATION ON N-TYPE 4H-SIC
[attachment=43495]
ABSTRACT
The doping dependence of dry thermal oxidation
rates in n-type 4H-SiC was investigated.
The oxidation was performed in the temperature range 1000oC to 1200oC for samples with nitrogen doping in the range of 6.5×1015/cm3 to 9.3×1018/cm3, showing a clear doping dependence.
Samples with higher doping concentrations displayed higher oxidation rates.
The results were interpreted using a modified Deal-Grove model.
5 STEPS IN THERMAL OXIDATION
1.Transport molecular O2 gas to the O2 Surface
2. In-diffusion of O2 through the oxide film
3. Reaction with SiC at the oxide/ SiC interface
4. Out diffusion of product gases through the oxide film
5.Removal of product gases away from the oxide surface
CONCLUSION
In this study of 4H-SiC nitrogen doping (6.5×1015/cm3 to 9.3×1018/cm3) dependence of dry thermal oxidation, the oxidation rate was found to increase with doping concentration
These changes were attributed to doping induced
lattice mismatch, as well as the stronger Si-N bond as compared to the Si-C bond,
oxidation of SiC may, in some cases, be defect-mediated.
[attachment=43495]
ABSTRACT
The doping dependence of dry thermal oxidation
rates in n-type 4H-SiC was investigated.
The oxidation was performed in the temperature range 1000oC to 1200oC for samples with nitrogen doping in the range of 6.5×1015/cm3 to 9.3×1018/cm3, showing a clear doping dependence.
Samples with higher doping concentrations displayed higher oxidation rates.
The results were interpreted using a modified Deal-Grove model.
5 STEPS IN THERMAL OXIDATION
1.Transport molecular O2 gas to the O2 Surface
2. In-diffusion of O2 through the oxide film
3. Reaction with SiC at the oxide/ SiC interface
4. Out diffusion of product gases through the oxide film
5.Removal of product gases away from the oxide surface
CONCLUSION
In this study of 4H-SiC nitrogen doping (6.5×1015/cm3 to 9.3×1018/cm3) dependence of dry thermal oxidation, the oxidation rate was found to increase with doping concentration
These changes were attributed to doping induced
lattice mismatch, as well as the stronger Si-N bond as compared to the Si-C bond,
oxidation of SiC may, in some cases, be defect-mediated.