Experimental and modeling study of the capacitance–voltage characteristics of metal–insulator–semiconductor capacitor based on pentacene/parylene

• Published in: Thin solid films Vol. 519; no. 13; pp. 4313 - 4318
• Main Authors: Wondmagegn, W.T., Satyala, N.T., Mejia-Silva, I., Mao, D., Gowrisanker, S., Alshareef, H.N., Stiegler, H.J., Quevedo-Lopez, M.A., Pieper, R.J., Gnade, B.E.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 29-04-2011; Elsevier
• Subjects: Capacitance; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Defects; Diffusion; interface formation; Dispersion; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in interface structures; Exact sciences and technology; Interface; Metal-insulator-semiconductor structures (including semiconductor-to-insulator); Pentacene; Physics; Poole–Frenkel; Solid surfaces and solid-solid interfaces; Surface double layers, schottky barriers, and work functions; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Pentacene; Capacitance; Poole–Frenkel; Interface; Dispersion; Defects; Defect states; MIS structures; Work functions; Digital simulation; Theoretical study; Dispersions; Poole-Frenkel; Experimental study; CV characteristic; Charge density; Interfaces; Experimental result; Numerical analysis; Logic gates; Organic semiconductors; Modelling; Diffusion; Active material; MIS capacitors
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2011.02.014

The capacitance–voltage (C–V) characteristics of metal–insulator–semiconductor (MIS) capacitors consisting of pentacene as an organic semiconductor and parylene as the dielectric have been investigated by experimental, analytical, and numerical analysis. The device simulation was performed using two-dimensional drift-diffusion methods taking into account the Poole–Frenkel field-dependent mobility. Pentacene bulk defect states and fixed charge density at the semiconductor/insulator interface were incorporated into the simulation. The analysis examined pentacene/parylene interface characteristics for various parylene thicknesses. For each thickness, the corresponding flat band voltage extracted from the C–V plot of the MIS structure was more negative than −
2.4
V. From the flat band voltage the existence of a significant mismatch between the work functions of the gate electrode and pentacene active material has been identified. Experimental and simulation results suggest the existence of interface charge density on the order of 3
×
10
11
q/cm
2 at the insulator/semiconductor interface. The frequency dispersion characteristics of the device are also presented and discussed.