Crossing Automation - Technology Highlights
Crossing Automation is at the leading-edge of automation technology development for semiconductor, MEMS and green technology-related manufacturing; as part of our commitment to driving the most effective, cost-efficient automation systems, our engineering department consistently strives to identify new approaches to automation technology and unique and innovative ways to implement existing and off-the-shelf components to increase customers' ROI and decrease time to market.
Check back regularly to see the latest developments at Crossing Automation and what the company is doing to further increase our customers' performance, and ultimately, profitability.
Compact, Cost-Effective Modular Vacuum Platform Design
As the market for integrated vacuum platforms has grown beyond the conventional semiconductor cluster tool, requirements for smaller and lower cost systems have raised the bar for the platform designer. Long process times can significantly undercut the value provided by a onesize-fits-all design and are pushing semiconductor manufacturers to identify alternative approaches.
One such approach is to implement the concept of module re-use and derivative designs that can break through the cost-size barriers. One example of this design (Fig. 1) is built around a standard Shuttle-Lock&0153; module, which functions as a load-lock as well as a wafertransfer device. A standard BOLTS-compatible loadport, coupled with a compact mini-environment, provides a standard interface to the fab for material movement. An atmospheric aligner provides the required wafer orientation and centering to satisfy any process module requirements. The aligner, loadport, and vacuum transfer elements are all completely standard. Only the packaging is original and supports the existing interface standards prevalent in the industry.
The resulting design (Fig. 2) provides a very compact system(< 0.7 m2) that fully utilizes two process modules running cycle times in the 15-20 minute range. The cost of such a system is easily less than half that of a conventional cluster tool and the software integration can be done in the same manner as any other Crossing platform, leveraging the API interface and device libraries.
Behind the Technology: Wafer Engine™
Automation Technology As I See It: Anthony Bonora
Automated wafer handling technology began with the use of tweezers and vacuum pencils in the 1970s then moved to O-ring drive systems and other specialized mechanical transfer systems in the early 1980s. The advent of larger diameter wafers, including 150 mm and 200 mm, coupled with the requirements for backside cleanliness, random access requirements and the advent of the SEMI/MESC standards, resulted in a gradual adoption of the SCARA style folding arm robots in the late 1980s that are still prominent today. The slow adoption of standards and the poor adherence to a wafer transfer plane standard led to a multitude of tool architectures that required diverse and specialized robots with highly customized designs.
In the late 1990s the 300 mm wafer size transition began; this change was accompanied by rigorous new standards for tool loading heights and loadport interfaces for all process and metrology tools in a fab. While these standards narrowed the need for the specialized choices for wafer handling solutions, and in some cases actually reduced tool flexibility and throughput rates, positive benefits included the rapid evolution and adoption of interchangeable front opening unified pod (FOUP) loadports and the adoption of equipment front end modules (EFEMs) and factory automated material handling systems (AMHS) as an industry-wide norm for 300 mm manufacturing. These standards also played an important role for the transition to the AMHS that improved factory scheduling efficiency and removed ergonomic barriers for handling heavier wafer containers.
A fresh examination of wafer handling approaches to optimize EFEM performance was initiated in the early 2000 timeframe. At that time there was significant diversity in new wafer handling requirements, which were challenging to meet with the conventional SCARA robot designs.
These new demands included:
- The ability to perform dual-swap wafer exchanges very rapidly for the higher throughput tools that were coming to market.
- High placement accuracy to minimize the time required for pattern acquisition in certain process and metrology tool applications.
- Flexible and/or extendable horizontal travel to support a growing number of EFEMs utilizing more than three loadports.
- Improved serviceability and access within the EFEM.
A variety of architectural approaches were analyzed and ranked in terms of their ability to measurably achieve differentiated performance relative to the existing status quo. The Wafer Engine™ approach was selected as offering the most favorable combination of attributes for the anticipated requirements of the next generation of semiconductor processing tools.
The Wafer Engine architecture is decidedly different than conventional SCARA robots in terms of how precision motion profiles are generated and controlled for the different wafer moves that are typically required in EFEMs and Sorters.
Key differences include:
- Improved Wafer Exchanges to/from a FOUP
- Improved Airborne Particulate Management
- Extendable Z Travel
- Extendable Horizontal (X) Travel
- Improved Serviceability and Access
- Increased Opportunities for Future Wafer Engine Enhancements