Peter Nunan

Using Multiple Implant Regions To Reduce Development Wafer Usage

The cost of new process development has risen significantly with larger wafer sizes and the increased number of fabrication steps needed to create advanced devices. The high value of each 300 mm development wafer has spurred efforts to find a way to explore more than a single process setting with each wafer. Traditional methods of defining multiple spatially distinct implant regions on a single wafer achieve poor utilization of device die. The need for efficient utilization of the die and wide process latitude for defining multiple implant regions per wafer has led to the development of an implant proximity mask (vMask™), which permits sharply defined borders between implant regions that may have different species, energy, angle, or dose. The capability of this system to achieve multiple spatially resolved implant conditions per wafer with high die utilization and using the same process parameters as production implants will be described. Specifically, results for measurement of the uniform process area, ...

High Current Implant Precision Requirements for Sub‐65 nm Logic Devices

As CMOS devices shrink they become increasingly sensitive to variations of ion beam angular properties and beam current density. In sub‐65 nm devices beam divergence and beam steering variations at levels commonly seen in high current implanters for Source/Drain Extension (SDE) implants could significantly shift device characteristics compromising yield and robustness of manufacturing process. In this paper we review the implant precision requirements for Source/Drain Extension (SDE) formation for sub‐65nm node devices. TCAD simulation was used to analyze the effects of beam divergence and steering errors for an on‐axis (0°) SDE implant on sub‐65 nm NMOS HP devices. Effects of energy contamination introduced along with decelerated low energy ions in p‐type SDE implants in PMOS devices is also discussed. Response of device electrical characteristics to variation of beam angle properties is quantified and beam angle control requirements for state‐of‐the‐art ultra‐low energy implanters formulated.