Oxide Thin-Film Transistors for OLED Displays

Review of Material Properties of Oxide Semiconductor Thin Films Grown by Atomic Layer Deposition for Next-Generation 3D Dynamic Random-Access Memory Devices

“…This superior stability against NBS can be attributed to the limited presence of hole carriers in most AOS materials. 239 Nevertheless, NBS conditions can stimulate the creation of electron−hole pairs from deep-level subgap states above the valence band edge when subjected to visible/ultraviolet light. These pairs, once formed, are separated by the internal electric field under NBS conditions.…”

Progress, Challenges, and Opportunities in Oxide Semiconductor Devices: A Key Building Block for Applications Ranging from Display Backplanes to 3D Integrated Semiconductor Chips

“…The PBS‐induced V TH instability can be attributed to: 1) trapping of accumulated electrons at the interface between a gate insulator (GI) and an AOS channel layer or 2) their injection into bulk trap states of GI ( Figure ). [ 18,30 ] This indicates that the N e of AOS channel layer is reduced during the PBS condition, leading to a positive shift of the V TH . Here, a V O site existing near some undercoordinated In (In*) cation (referred to as In*–M by Nahm and Kim) can be an intrinsic acceptor‐like trap, which easily captures two electrons and converts to (In*–M) 2− states, aggravating the PBS stability in the In‐based AOS with oxygen deficiency.…”

“…This implies that the stability against the NBS conditions is generally superior to that against the PBS conditions, which can be mainly attributed to scarcity of hole carriers in most of the AOS. [ 30 ] However, electron–hole pairs can be generated from deep level subgap states above the VB edge by exposure to visible/ultraviolet (UV) light; these pairs are separated by the local electric field under NBS conditions (Figure 4). [ 30 ] In particular, photoinduced hole carriers move toward the interface between the GI and channel layer, being trapped (injected) at the interface (into the bulk of GI).…”

“…[ 30 ] However, electron–hole pairs can be generated from deep level subgap states above the VB edge by exposure to visible/ultraviolet (UV) light; these pairs are separated by the local electric field under NBS conditions (Figure 4). [ 30 ] In particular, photoinduced hole carriers move toward the interface between the GI and channel layer, being trapped (injected) at the interface (into the bulk of GI). This results in significant deterioration in the reliability against the NBS conditions, which is called negative gate bias illumination stress (NBIS).…”