TITLE

Abnormal dependence of contact resistivity on hole concentration in nonalloyed ohmic contacts to p-GaN

AUTHOR(S)
Kwak, Joon Seop; Nam, Ok-Hyun; Park, Yongjo
PUB. DATE
May 2002
SOURCE
Applied Physics Letters;5/13/2002, Vol. 80 Issue 19, p3554
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
The dependence of contact resistivity on hole concentration has been investigated for nonalloyed Pd contacts to p-GaN. The hole concentration was varied by changing the Mg concentration, [Mg], in p-GaN. The p-GaN having the [Mg] of 4.5×10[sup 19] cm[sup -3] showed the hole concentration of 2.2×10[sup 17] cm[sup -3], where contact resistivity was measured as 8.9×10[sup -2] Ω cm[sup 2]. When the [Mg] increased to 1.0×10[sup 20] cm[sup -3], the hole concentration was significantly reduced to 2.0×10[sup 16] cm[sup -3]. Nevertheless, the Pd contacts on the p-GaN displayed contact resistivity as low as 5.5×10[sup -4] Ω cm[sup 2]. The abnormal dependence of contact resistivity on hole concentration may be explained by predominant current flow at the Pd/p-GaN interface through a deep level defect band, rather than the valence band. © 2002 American Institute of Physics.
ACCESSION #
6630270

 

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