The contact mechanism and design principles for alloyed Ohmic contacts to n-GaN were investigated in Mohammad's paper [J. Appl. Phys. 95, 7940 (2004)]. Mohammad's study demonstrated that both tunneling and thermionic emission were equally important for low resistivity at the metals/ n-GaN interfaces. As regards this Comment, we point out the fundamental errors of this interpretation. In addition, we find that the results shown in Figs. 3-6 of Mohammad's paper are incorrect because the lower effective barrier height (BH) of less than 0 eV (due to the induced BH reduction by image force lowering or band gap narrowing) and a variable (c1) were neglected by the author.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)
- Physics and Astronomy(all)