Grain boundary induced short-term memory effect in fully depleted thin-polysilicon devices

In this paper, we investigate the floating body effect (FBE) in fully depleted polysilicon-body ultrathin-body MOSFETs. Generally, the FBE cannot occur in a fully depleted body. However, we demonstrate that an FBE-like phenomenon can be observed in fully depleted polysilicon-body MOSFETs due to the grain boundaries of the polysilicon. To analyze this, devices with various conditions were fabricated and measured. As a result, we may argue that generated holes can be trapped at grain boundaries, which causes an FBE-like phenomenon. Based on this, we expect that thin-polysilicon devices can be utilized for various applications such as 1T-DRAM or synaptic devices.