Vita Controller: Bringing Modern Capabilities to Legacy Tools
By Jeffrey Dietz and Florent Ducrot
Smart watches provide information beyond just the time of day; “connected cars” provide important new safety and infotainment features; and Applied Materials’ Vita controller enables a wealth of modern automation and control capabilities for users of Applied’s 200mm tools, such as statistical process control (SPC), predictive run-to-run control and significantly higher speed of execution.
Introduced in 2014, the Applied Vita controller replaces aging system controllers in legacy tools. Today, the company’s technology-enabled service experts know how to fully utilize the Vita controller’s state-of-the-art data communications, processing, and storage features to tap into the torrent of process- and equipment-related data flowing from these tools to achieve greater and more consistent performance than ever before.
To date, more than 350 Vita units have been installed by some 60 customers worldwide on their Applied Materials Endura and Centura tools. Users are realizing substantial gains in performance, productivity, throughput, tool stability, system availability and overall cost of ownership, all of which have been achieved with total recipe transparency and backward-compatibility with the original software.
These results are being reported across this Vita installed base on all platforms and technologies, for applications which include:
- PVD (Al slab and fill, MOCVD liner barrier)
- Etch (aluminum, polysilicon, dielectric)
- CVD (HDP, SiH4, TEOS)
- Thermal (poly, epi, RTP, LPCVD)
More recently, the Vita controller has been released for use with Applied’s Producer tools. Early results demonstrate throughput improvements of up to 2.3%, faster data sampling rates, improved data quality and gains of up to 37% in automation communication speed.
Optimizing the Older Installed Base
Through close collaboration with Applied Materials, users who want to optimize their legacy equipment cost-effectively can accelerate the implementation of modern monitoring and control techniques, which are proven to increase yields and reduce overall cost of ownership.
Applied’s specialized TechEdge service engineer teams combine analytical skills with deep process tool expertise and detailed knowledge of advanced production technologies to quickly and effectively upgrade tools with the Vita controller. These proven capabilities are available to customers with Applied Materials comprehensive service agreements.
In the two years since its introduction, the Vita controller’s speed and bandwidth have enabled TechEdge engineers to use modern software leveraging univariate and multivariate analysis to discover and solve many different types of difficult problems with customers’ legacy tools (see Table 1).
Table 1: The analyses enabled by the Vita controller’s modern data-handling and high-speed communications capabilities have brought customers many benefits, such as the ones listed in the table.
Following are some specific examples of the kinds of improvements customers are achieving with upgraded legacy tools some of which are as much as two decades old running production processes at sites around the world.
One customer reduced unscheduled downtime and defects related to excessive chucking forces in a Centura tool (see Figure 1).
The problem occurred when lift pins were actuated. They generated excessive stress on wafers, which caused wafer breakage and/or particle defects, and also led to excessive stress on chamber mechanical components with premature failures.
Once the Vita controller was installed, Applied TechEdge engineers were able to do analysis from high resolution data traces. These analyses were conducted via Applied’s proprietary maintenance software in a predictive mode for early detection of residual chucking conditions.
A better understanding of these conditions enabled the excessive chucking forces to be addressed, eliminating wafer stress and breakage, with reduction of associated particles.
In addition, a 4% reduction in unscheduled downtime was achieved bringing the unscheduled-to-scheduled ratio to industry benchmark with a positive impact on the tool availability (a 1.3% average throughput increase). Finally, parts consumption was also reduced due to less premature failure of mechanical lift components.
Once established, this method was proliferated to the customer’s entire toolset, and optimized hardware matching enabled more predictable output.
Figure 1. Data from the Vita controller enabled an Applied Materials TechEdge engineer to analyze residual chucking conditions in order to predict problems with lift pins. The analysis showed voltage fluctuations associated with lift pin operation. This insight enabled corrective actions to be taken and excessive chucking forces to be reduced.
In a second example, a customer’s fab was heavily loaded (>95% utilization). The customer needed to reduce variability and increase overall throughput of a 200mm Endura bottleneck tool.
The customer engaged Applied Materials under a Managed Service Agreement, which included replacement of the old controller with Vita technology and also featured the addition of clean-in-place (CIP) hardware.
The resulting improved data acquisition and analysis capabilities helped the customer understand the root causes of the tool’s excursions and, together with the CIP hardware, delivered an 11.8% reduction in throughput variability and a throughput increase of 1.9% (see Figure 2). With these improvements the customer was able to more effectively fine-tune wafer flow throughout the fab for better cycle time.
Figure 2. One customer’s 200mm Endura tool was experiencing excursions that both increased throughput variability and reduced overall throughput. These limitations hindered workflow in the fab. Data was extracted from the Vita controller and analyzed, and together with new clean-in-place (CIP) hardware, it enabled the tool’s performance to be upgraded such that an 11.8% reduction in throughput variability and a throughput increase of 1.9% was achieved.
Another customer was experiencing recurring mismatched thickness uniformity beyond specification across chambers in a Centura tool, resulting in 50% downtime and excessive engineering hours spent in troubleshooting the problem
Applied’s TechEdge engineer leveraged the data collected from the Vita controller to perform FDC analysis and hardware- and PM-audits, to identify the root causes. He-carrier gas flow rates were subsequently identified as the largest contributing factor.
The collected data were also used to optimize post-clean seasoning time and RF power settings.
As a result, thickness non-uniformity was improved from >3% (1σ) to < 1.5% (1σ), enabling the process specification to be met (see Figure 3), and addressing the chamber/process dedication previously implemented. This overall program also enabled better WIP management.
|Figure 3. The graph at left shows differences in He-carrier gas flow rates in two chambers of a customer’s Centura tool. These differences led to the production of films with non-uniform thicknesses among chambers. The graph on the right shows that following analytical studies enabled by data from the Vita controller, film thickness uniformity was significantly increased.|
By maximizing output, tool stability and predictability on Centura and Endura platforms, an accelerated ROI was reported for both these programs.
The Vita controller is more than just a replacement for the vintage controller supplied with legacy 200mm tools. Its modern architecture and sophisticated capabilities enable analytical information to be extracted, analyzed, classified and implemented under Applied service agreements by highly specialized, expert support teams.
For additional information, contact Florent_Ducrot@amat.com.