Admittance Spectroscopy of Interface States in ZnO/HfO2 Thin-Film Electronics

作者：Siddiqui Jeffrey J^*; Phillips Jamie D; Leedy Kevin; Bayraktaroglu Burhan

来源：IEEE Electron Device Letters, 2011, 32(12): 1713-1715.

DOI：10.1109/LED.2011.2170399

• Admittance spectroscopy (AS)
• hafnium oxide (HfO2)
• interface charge density
• zinc oxide (ZnO)

The electronic properties of ZnO/HfO2 interface states are studied by dc current-voltage and ac admittance spectroscopy on thin-film transistors (TFTs) and metal-insulator-semiconductor capacitor structures. Subthreshold behavior of the transistors indicates an interface state density (N-it) value of 7.2 x 10(12) cm(-2). Cole-Cole plots of ac admittance demonstrate Debye behavior and extracted energy-dependent interface state density (D-it) with an approximate exponential decay of 3.0 x 10(13) cm(-2) . eV(-1) near the conduction band to 1.2 x 10(12) cm(-2) . eV(-1) at 0.9 eV below the conduction band. The integrated interface state density from these measurements is N-it = 7.9 x 10(12) cm(-2), which is consistent with the value obtained from subthreshold behavior of the TFTs.

• 出版日期2011-12