Ambient Pressure Dependent Characteristics of F₁₆CuPc Transistors with Polyimide and SiO₂ Gate Insulators

Abstract

N-channel organic field effect transistors (FETs) with F₁₆CuPc/SiO₂(300 nm)/Si and F₁₆CuPc(20 nm)/Polyimide(320 nm)/Si structures were fabricated, and the transistor electrical characteristics measured in the air and in a vacuum at a pressure below 1.3 Pa were compared. The threshold voltage V_th and the mobility μ of the transistor with the SiO₂ gate insulator are strongly dependent of the ambient pressure during the measurements, while those of the transistor with the Polyimide gate insulator are nearly independent of the ambient pressure during the electrical measurements. The change of the transistor characteristics on the ambient pressure might be attributed to the absorption and desorption of some negatively charged chemical species on the transistor channel interface region.

Keywords:

• organic thin film transistor
• perfluorinated copper phthalocyanine
• polyimide

Acknowledgments

This work has been supported by the Frontier Project of the Japan Ministry of Education, Culture, Sports, and Science and Technology.