Minimizing the off-state current is mandatory for the development of low power consumption circuits based on organic thin-film transistors (OTFTs). Small OTFTs which are required for compact circuits suffer from parasitic current pathways through the semiconductor and hence precise patterning of the semiconductor film is essential. Since state-of-the-art patterning techniques such as oxygen based reactive ion etching usually severely damage the organic transistors, usually OTFTs with a large channel width W are discussed in the literature in order to circumvent this problem. Here we demonstrate that precise patterning of organic semiconductor films for OTFT using reactive ion etching is possible without compromising the transistor performance. If adequate etching conditions and appropriate masks are chosen, oxygen radicals do not affect the organic transistor because lateral diffusion as well as vertical bombardment of ions through the etching mask do not occur. With the method presented here, we show small footprint OTFTs with $W/L$ = 25 μm/10 μm and leakage current levels as low as 10 fA/μm which enable organic transistors to be used for demanding electronic applications such as high resolution active-matrix displays or photo detector arrays.

对于基于有机薄膜晶体管（OTFT）的低功耗电路的开发，必须最小化断态电流。紧凑电路所需的小型OTFT会受到穿过半导体的寄生电流路径的影响，因此精确地构图半导体膜至关重要。由于诸如氧气基反应性离子刻蚀之类的最先进的构图技术通常会严重破坏有机晶体管，因此通常具有较大沟道宽度W的OTFT为了避免这个问题，文献中对此进行了讨论。在这里，我们证明了在不影响晶体管性能的情况下，使用反应性离子蚀刻对OTFT进行有机半导体薄膜的精确构图是可能的。如果选择适当的蚀刻条件和适当的掩膜，则氧自由基不会影响有机晶体管，因为不会发生横向扩散以及离子通过蚀刻掩膜的垂直轰击。通过此处介绍的方法，我们展示了具有以下功能的小尺寸OTFT$\mathrm{w\; ^}/\mathrm{大号}$ = 25μm/ 10μm，泄漏电流低至10 fA /μm，这使有机晶体管可用于要求苛刻的电子应用，例如高分辨率有源矩阵显示器或光电探测器阵列。