Development of monolithic integration of MEMS switch and TFT as a hybrid complementary logic inverter

Abstract

Recently, the flexible electronics have become an exciting research area drawing active participation of scientists and engineers from both academia and industry due to the following advantages: large area production, low production cost, and various functionalities. In order to demonstrate the flexible electronics, it is necessary to build an integrated circuit on the flexible substrate and a thin-film transistor (TFT) is the most promising candidate as a switch used for flexible integrated circuit due to the low fabrication temperature process and large area production capabilities. Among other types of TFTs, an oxide TFT is the one that gets the most spotlighted since it has high performance in compare to the others. As you may already have known, the research has been well developed and progressed with n-type oxide TFT; however, despite the fact that n-type oxide TFT shows such excellent device characteristics, the p-type oxide TFT is still remained as a problematic issue- the device has high leakage current, low on/off ratio, and requires high fabrication temperature. Thus, the flexible integrated circuit using p-type and n-type oxide TFTs is currently facing a limitation. In this thesis, we suggested the novel concept to demonstrate the hybrid complementary logic inverter with MEMS switch and n-type oxide TFT. Here, MEMS switch and n-type oxide TFT are integrated together on the same substrate (monolithically integrated) to work as a logic inverter. After the demonstration, the characterizations of n-type oxide TFT and MEMS switch were performed to confirm that two devices were working properly without any problems. Through the measurements, we concluded that our MEMS switch had better switching characteristics in comparison with the current p-type oxide TFT in terms of leakage current and on/off switching ratio. Then finally, we investigated the characteristics of proposed hybrid complementary logic inverter. Our new concept of hybrid complementary logi...