TY - JOUR
T1 - Gaussian distribution of inhomogeneous barrier height in tungsten/4H-SiC (000-1) Schottky diodes
AU - Toumi, S.
AU - Ferhat-Hamida, A.
AU - Boussouar, L.
AU - Sellai, A.
AU - Ouennoughi, Z.
AU - Ryssel, H.
N1 - Funding Information:
Dr. Z. Ouennoughi is supported by the Algerian ministry of research (MESRS) for an academic year in SQU.
PY - 2009/3
Y1 - 2009/3
N2 - The Gaussian distribution model have been used to analyze the anomalies observed in tungsten (W)/4H-SiC current voltage characteristics due to the barrier inhomogeneities that prevail at the metal-semiconductor interface. From the analysis of the forward I-V characteristics measured at elevated temperatures within the range of 303-448 K and by the assumption of a Gaussian distribution (GD) of barrier heights (BHs), a mean barrier height over(Φ, ̄)B 0 of 1.277 eV, a zero-bias standard deviation σ0 = 0.092 V and a factor T0 of 21.69 K have been obtained. Furthermore the modified Richardson plot according to the Gaussian distribution model resulted in a mean barrier height over(Φ, ̄)B 0 and a Richardson constant (A*) of 1.276 eV and 145 A/cm2 K2, respectively. The A* value obtained from this plot is in very close agreement with the theoretical value of 146 A/cm2 K2 for n-type 4H-SiC. Therefore, it has been concluded that the temperature dependence of the forward I-V characteristics of the W/4H-SiC contacts can be successfully explained on the basis of a thermionic emission conduction mechanism with Gaussian distributed barriers. In addition, a comparison is made between the present results and those obtained previously assuming the pinch-off model.
AB - The Gaussian distribution model have been used to analyze the anomalies observed in tungsten (W)/4H-SiC current voltage characteristics due to the barrier inhomogeneities that prevail at the metal-semiconductor interface. From the analysis of the forward I-V characteristics measured at elevated temperatures within the range of 303-448 K and by the assumption of a Gaussian distribution (GD) of barrier heights (BHs), a mean barrier height over(Φ, ̄)B 0 of 1.277 eV, a zero-bias standard deviation σ0 = 0.092 V and a factor T0 of 21.69 K have been obtained. Furthermore the modified Richardson plot according to the Gaussian distribution model resulted in a mean barrier height over(Φ, ̄)B 0 and a Richardson constant (A*) of 1.276 eV and 145 A/cm2 K2, respectively. The A* value obtained from this plot is in very close agreement with the theoretical value of 146 A/cm2 K2 for n-type 4H-SiC. Therefore, it has been concluded that the temperature dependence of the forward I-V characteristics of the W/4H-SiC contacts can be successfully explained on the basis of a thermionic emission conduction mechanism with Gaussian distributed barriers. In addition, a comparison is made between the present results and those obtained previously assuming the pinch-off model.
KW - Electrical measurements
KW - Inhomogeneity
KW - Schottky barrier
KW - Silicon carbide
KW - Tungsten
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U2 - 10.1016/j.mee.2008.10.015
DO - 10.1016/j.mee.2008.10.015
M3 - Article
AN - SCOPUS:59349090576
SN - 0167-9317
VL - 86
SP - 303
EP - 309
JO - Microelectronic Engineering
JF - Microelectronic Engineering
IS - 3
ER -