Low-temperature and scalable complementary thin-film technology based on solution-processed metal oxide n-TFTs and pentacene p-TFTs

Abstract

In this work, a completely scalable integration process is presented for organic–inorganic complementary logic, based on low-temperature spin-coated n-type metal oxide TFTs and thermally evaporated p-type pentacene TFTs. Both transistor types are photolithographically processed side-by-side, without the use of any shadow mask. High performance n-type metal oxide TFTs, post-annealed at a maximum temperature of only 250 °C, exhibit saturation mobilities exceeding 2 cm 2/(V s), subthreshold swing as low as 0.19 V/decade and I on/ I off ratios beyond 10 7 after integration with p-type pentacene TFTs. Using this hybrid complementary technology, 5-stage and 19-stage ring-oscillators are demonstrated, operating at supply voltages as low as 2.5 V. The ring-oscillators oscillate at a frequency of more than 110 kHz, corresponding to stage delays as low as 0.74 μs, at a supply bias of 20 V.