Benefits of Zero Degree Single Wafer High Energy Implants for Advanced Semiconductor Device Fabrication

High energy well implants for retrograde well formation are usually tilted to avoid channeling. However, this can cause the well profile under the STI (Shallow Trench Isolation) to be skewed or asymmetric due to shadowing by the resist. This results in poor inter-well isolation and increased leakage currents. This problem becomes more pronounced below 65 nm design rules. In this paper, using experimental data and TCAD simulations we demonstrate the improvement in inter-well isolation and junction characteristics that can be achieved with true-zero well implants. Finally, we briefly discuss the corresponding die shrinkage that can be expected.