ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Experimental results obtained from current–voltage (I–V) and capacitance–voltage techniques along with admittance spectroscopy have been qualitatively correlated to achieve a more comprehensive picture of dopant freeze-out and conduction mechanisms in a 6H–SiC n+p-type junction. Special attention was paid to the temperature range of 100–200 K. The dependence of the ideality factor, n, on the temperature was obtained experimentally from the I–V measurements. Two contributions have been considered in its evolution. At room temperature, n is very close to 2, indicating that recombination processes dominate the forward conduction mechanism. This result may be related to the SiC sample preparation process: structural defects may be present at the junction interface giving rise to interface states which act as recombination centers. At low temperatures (100–200 K), the Poole–Frenkel effect on the impurity level is the main effect responsible for the nonideal behavior of the junction. We have carried out a quantitative estimation of the n factor predicted by this effect incorporating partial ionization of the dopant. These calculations agree very well with the experimental values. At these temperatures the thermal excitation is low, the traps remain inactive, and their contribution to the conduction mechanisms is negligible. When the temperature increases, traps become thermally activated and then the recombination processes participate in the conduction mechanisms and they become dominant at room temperature. The admittance analysis allows numerical values of the aluminum emission rate to be obtained at different temperatures. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.360831
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