Influence of batch-to-batch substrate variation and cone effect on high energy implant distribution profile

Abstract

High-energy well implants for advanced 0.18μm CMOS technologies are performed at normal incidence angles for minimizing the shadowing caused by the thick photoresist and the STI dimensions. Under these conditions (high-energy, normal incidence), even a small variation in angle can cause a significant variation on the well profile and can negatively impact the device performances. In this article both batch-to-batch variation and cone effect on batch implanter are discussed and analyzed. The analysis was done using Thermo-Wave (T.W.) and Secondary Ion Mass Spectrometry (SIMS) analysis. A good correlation between T.W. and SIMS, which can help predicting the distribution profile with T.W. results, was found. Some possible solutions are suggested.