Paul J. Marganski

A Vaporizer for Decaborane and Octadecaborane

Decaborane (B10H14) and Octadecaborane (B18H22) are two promising new doping materials for performing very shallow boron implants at high implanter throughput. However, because these new materials are low‐vapor pressure solids at room temperature, their delivery to the implanter’s ion source requires specialized techniques to deliver the desired mass flow without condensation. Data are presented which describe several features of a vaporizer for producing Decaborane and Octadecaborane flows in a production environment. This paper will also focus on the critical design aspects of the vapor delivery system, including the effects of vaporizer geometry on vapor flow rate, the performance of various flow control systems, and the overall thermal design. In addition, data on physical and environmental, safety, and health properties of these materials are presented. The effectiveness of this system as a stable vapor source for an ion implanter will be described.

Optimization of Xenon Difluoride Vapor Delivery

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 °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...

Development of “Static” In‐Situ Implanter Chamber Cleaning

Since the introduction of XeF2 in‐situ cleaning, its use in production implanters has been mainly focused on cleaning ion sources by flowing the cleaning vapor through the source arc chamber. This has been called “Dynamic” in‐situ cleaning. “Static” in‐situ cleaning is a different method under development at ATMI which allows an entire vacuum chamber and its contents to be cleaned. The chamber is filled to a pressure of 1–3 Torr of XeF2 vapor, which reacts with deposited material on all internal surfaces, and the reaction by‐products are then pumped away. When applied to the source vacuum chamber, the Static cleaning method allows cleaning vapor to contact components, such as the HV bushing and the manipulator assembly, which may not be adequately cleaned with the Dynamic method. Recently, ATMI has installed a prototype Static in‐situ cleaning system on an in‐house Ion Source Test Stand in Danbury, CT. This paper will describe the prototype cleaning system and process and its applicability to production i...

Emissions Monitoring and Exhaust Analysis for the Axcelis Optima HD IMAX Ion Implanter

As integrated circuit features continue to become smaller, it has become difficult to meet the challenges of shallow junction implant using conventional ion implant dopant species. To meet this challenge, Axcelis has developed the Optima HD IMAX, a new ion implant tool that uses the molecular dopant species octadecaborane (ClusterBoron®, B18H22) and also has the capability to perform carbon implants using at least two molecular carbon‐based species (ClusterCarbon™, C14H14 and C16H10). An additional feature of the tool is an integrated chemical clean based on NF3 remote plasma technology. The use of new materials in this tool has generated the need for understanding the potential emissions and release vectors of the process materials and their byproducts. Presented here are data on exhaust emissions obtained using Fourier Transform Infrared (FTIR) spectroscopy. Additionally, FTIR spectroscopy has been used to measure concentration levels of residual species that might be found in the source and process cha...