Gordon Angel

Metrology Requirements For Single Wafer Ion Implanters

As production CMOS devices shrink to 90nm and below, the requirements for high quality ion beams increase in medium and high current implant systems. Critical variations in device performance can be related to changes in ion beam properties, such as ion beam size, shape and density as well as ion beam angle steering and distribution. Transistor properties are known to be sensitive not just to mean beam angle but also to details of the distribution of angles contained within the beam. As a result, modem single wafer implanters are required to monitor more than just the energy and dose of implanted ions. The process security provided by single wafer ion implantation can be ensured by measurements which verify the angle integrity of each setup and implant. Monitoring of energy contamination, another element of beam quality, allows end users to utilize the improved productivity of decel operation on high current implanters while maintaining minimal and, more importantly, repeatable energy contamination. Final...

In situ charging potential monitoring for a high current ribbon beam

We discuss measurements and modeling associated with the high current ion beam space charge neutralization. We show the importance of the electron temperature in maintaining low beam potential and induced voltage on implanted wafers.