[en] Static AutoClean is a new in-situ cleaning strategy in development at ATMI registered that enables increased process efficiency and safety in the ion implantation process. Like the Dynamic in-situ AutoClean technology previously introduced and released by ATMI, Static AutoClean utilizes XeF₂ chemistry for in-situ cleaning of hazardous contaminants and deposits. Static AutoClean, however, is targeted towards cleaning areas of the beam-line (like electrode insulators or source bushings) where cleaning efforts using Dynamic AutoClean may not be sufficient. An explanation of this cleaning strategy and results showing its effectiveness will be presented in a separate paper at this conference (S. Yedave et al.). This paper presents the surface analytical data and methods used to understand and evaluate the effectiveness of Static AutoClean in removing contaminants from surfaces within the source vacuum chamber. Energy Dispersive Spectroscopy (EDS) was used to track the magnitude and spatial distribution of contaminants present on the surfaces within various regions in the source chamber space of an implanter following ion source operation with a commonly used dopant gas. After in-situ cleaning, these same components and surfaces were re-evaluated by EDS to quantitatively determine the reduction in surface contaminants present within the chamber. Learnings regarding the distribution of implant process contamination within the source chamber as well as Static AutoClean's effectiveness in removing it will be presented.

[en] Germanium tetrafluoride has long been the standard dopant gas of choice for germanium implantation processes. While this material maintains several positive attributes (e.g., it is a nonflammable gas that is easily delivered to an ion source), its use can result in extremely short ion source lifetimes. This is especially the case for the situation when an ion implanter runs solely or predominantly GeF₄. Presented here is an examination of various potential solutions to the short source life problem, some of which enable significant improvement.

[en] Xenon difluoride (XeF₂) has been shown to provide many process benefits when used as a daily maintenance recipe for ion implant. Regularly flowing XeF₂ into the ion source cleans the deposits generated by ion source operation. As a result, significant increases in productivity have been demonstrated. However, XeF₂ is a toxic oxidizer that must be handled appropriately. Furthermore, it is a low vapor pressure solid under standard conditions (∼4.5 torr at 25 deg. C). These aspects present unique challenges for designing a package for delivering the chemistry to an ion implanter. To address these challenges, ATMI designed a high-performance, re-usable cylinder for dispensing XeF₂ in an efficient and reliable manner. Data are presented showing specific attributes of the cylinder, such as the importance of internal heat transfer media and the cylinder valve size. The impact of mass flow controller (MFC) selection and ion source tube design on the flow rate of XeF₂ are also discussed. Finally, cylinder release rate data are provided.