Sensor X – Real Time Gas Composition, Atomic Vision
All semiconductor fabs employ a variety of gas composition sensors to understand the process chemistry during vacuum processes. For example, optical emission spectrometers (OES) are commonly found in etch and deposition chambers for end pointing key etch and dry clean processes. Residual gas analyzers (RGA) are commonly used to understand the possible contaminants inside a chamber for
troubleshooting purposes. As technologies scale beyond 32nm, these traditional sensor technologies are struggling to meet the required sensitivity requirements. Sensor X provides the highest sensitivity and signal to noise (S/N) performance by breaking up molecular gas species into their discrete atomic components. As such, Sensor X is quickly becoming the industry standard for applications that range from low exposed area oxide etch end point to micro-leak detection to general vacuum chamber troubleshooting.
The Sensor X SolutionSensor X creates a high density plasma within its micro-cavity during wafer processing. Molecular gas species within the chamber diffuse into the Sensor X micro-cavity and are then broken down to their atomic elements for identification using optical emission spectroscopy. The system consists of the Sensor X unit, an RF generator to power the remote plasma, a spectrometer to sample the atomic emission and a data collection / control / visualization system. Often, for chambers with existing OES systems, Sensor X can leverage the existing infrastructure, requiring only the micro-cavity and RF generator.
Atomic Spectra, High Sensitivity, Easy to UnderstandSensor X’s key differentiating feature lies in its ability to create an atomic emission spectrum versus the common molecular spectral fingerprints available with other sensors. Molecular emission peaks are difficult to identify and often overlap thereby degrading S/N performance. Sensor X’s atomic peaks however are discrete peaks that tend not to overlap for maximum S/N performance. Furthermore, these peaks are very easy to identify to a known atomic species given they have been extensively characterized by NIST.
Transparent to ProcessSensor X is designed to be completely transparent to the wafer processing environment. Extensive studies, performed by both Pivotal and its IDM and OEM customers (e.g., particle checks, etch / deposition rate studies), have demonstrated absolutely no impact to the wafer processing environment.
Easy to Install, Easy to MaintainSensor X mounts onto any available port that is in gaseous communication with the wafer processing environment. Once an available port is identified, installation is very simple and quick. With no moving parts or differential pumping systems, Sensor X is also very easy to maintain, requiring a possible sapphire window replacement on a annual basis.
End Point Low Exposed Area (< 1%) Critical Etch ProcessesSensor X provides a breakthrough approach to reliably calling end point on low exposed areas. For example, by focusing on atomic silicon emission peaks, the Sensor X system can enable existing etch end point systems to accurately catch end points during critical oxide etches. The results are improved post etch parametrics and yield, especially at smaller technology nodes that are highly susceptible to under or over etching.
End Point Various Dry Clean ProcessesDue to the frequency of dry cleans in etch and deposition processes, an effective dry clean end point system can significantly increase wafer throughput and reduce overall equipment cost of ownership. Sensor X has been proven to deliver reliable end points for a variety of processes including metal based dry cleans (e.g., Ti, W) post atomic layer deposition processes.
Identify Micro-Leaks In SituDeposition processes are becoming increasingly sensitive to micro-leaks (e.g., < 2mT / min rate of rise) and are a primary source of particle-related defect issues. Furthermore, standard off-line helium leak detection approaches are not able to identify “transient” leaks that occur momentarily when a certain pressure is achieved or valve movement occurs, often leading to multi-million dollar scrap events. With Sensor X’s strong S/N performance, even the smallest leaks can be identified during wafer processing and avoided immediately.
Troubleshoot & Match Chambers More EffectivelyComparing a “golden” chamber’s spectral fingerprint with a troublesome chamber can allow the tool engineer to immediately identify and troubleshoot the key issues. Sensor X has reduced months of troubleshooting time and money to days by easily and quickly identifying the sources of contamination that lead to poor wafer processing performance.
- SX1100 – Datasheet
- Advanced Etch End Point – Application Note
- Dry Clean End Point – Application Note
- Contamination Identification – Application Note
The Sensor X Solution
Atomic Spectra, High Sensitivity, Easy to Understand
Transparent to Process
Easy to Install, Easy to Maintain
End Point Low Exposed Area (< 1%) Critical Etch Processes
End Point Various Dry Clean Processes
Identify Micro-Leaks In Situ
Troubleshoot & Match Chambers More Effectively