Organic Permeable Base Transistors—Reliable Large-Scale Anodization for High Frequency Devices

Abstract

Organic permeable base transistors (OPBTs) have demonstrated impressive performance and potential in various applications, such as display driving circuits, light-emitting transistors, and logic circuits requiring high-frequency operation. However, large-scale implementation is hindered by fabrication reliability and repeatability issues, a problem also common with other types of organic transistors, leading to reliance on exceptional “hero” devices. To address this challenge, an electrochemical anodization process is scaled up and optimized for OPBTs to produce consistent performance across an entire 15 cm × 15 cm wafer. By controlling the Al base oxidation, an 87% yield of functional devices and a median transconductance of d−3is achieved S, proving that the anodization process does not degrade the device performance. Additionally, anodization reduces leakage current to below d−9A, increasing the current gain to a median of 10⁶, and decreases the oxide capacitance (C_ox) without affecting the transconductance (g_m), resulting in a driving-voltage normalized unity-gain cutoff frequency (f_T/V) of up to 2.6 MHzV⁻¹. The validity of the experimental results is confirmed through properly calibrated technology computer-aided design (TCAD) simulations, which rely on DC and small-signal AC analysis of OPBTs, based on the underlying physical equations.