Reduction of the Pass Gate Effect with a Spherical Shallow Trench Isolation in the BCAT Structure

We investigates the pass gate effect, a type of adjacent cell interference, through TCAD simulations of a typical DRAM structure at the 1y-nm technology node. Our results show that the pass gate effect is highly dependent on several factors, including the geometrical distance, the ratio between oxide and active silicon, and the oxide trap density at shallow trench isolation. To explain the pass gate effect, we used energy band diagrams and analyzed its tendencies in various environments. Based on our analysis results, we propose and optimize a spherical shallow trench isolation structure. Our analysis results convincingly demonstrate that the proposed structure is effective in mitigating the pass gate effect compared to typical structures.