Scientists at Tokyo Tech have developed a novel method using palladium to inject hydrogen into the deeply buried oxide-metal electrode contacts of amorphous oxide semiconductors (AOSs) storage devices. This breakthrough reduces contact resistance, addressing a key issue that has been hindering the application of AOSs in next-generation storage devices and displays.
Thin film transistors (TFTs) based on AOSs have shown great promise for high-density DRAM technologies but have struggled with contact issues that lead to high contact resistance. This impacts charge carrier mobility and increases power consumption, especially in vertically stacked architectures.
To combat this, the Tokyo Tech team developed a method where hydrogen is injected into the buried oxide-metal contacts using palladium. This catalyzes the dissociation of hydrogen at low temperatures, resulting in a highly conductive oxide layer that reduces contact resistance.
Lead researcher Assistant Professor Masatake Tsuji explained that the choice of metal electrode is crucial for the success of this method. In their study, they used palladium due to its ability to catalyze hydrogen dissociation and transport, making it ideal for hydrogen injection in AOS TFTs at low temperatures, even in deeply buried internal contacts.
The team demonstrated the effectiveness of this method by fabricating a-IGZO TFTs with Pd thin film electrodes and treating them in a hydrogen atmosphere at 150°C for 10 minutes. The result was a highly conductive interfacial layer formed by the reaction between oxygen and hydrogen, showcasing the potential of this innovative approach.
This research, published in the journal ACS Nano, opens up new possibilities for the practical application of AOSs in advanced storage devices, offering a promising solution to longstanding contact resistance issues.
