In the rapidly evolving field of semiconductor manufacturing, achieving fast, accurate and reliable thin film measurements within high aspect ratio (HAR) structures is critical. Chipmetrics offers unique silicon test structures on chips and on wafers as well as measurement services which are perfect solutions for high aspect ratio metrology. Our advanced solutions provide the necessary tools to ensure that these measurements are not only accurate but also efficient, for the demanding requirements of modern semiconductor processes.
The conformality of thin films in high aspect ratio (HAR) structures using new processes is often unpredictable. The kinetics of ALD film formation in HAR structures are fundamentally classified into two types: diffusion-controlled or reaction-controlled. Additionally, each precursor may have unique diffusion and reaction characteristics, which increases the complexity and the need for experimental approaches, especially when more than two precursors are involved. Conducting deposition experiments with PillarHall LHAR test structures provides rapid and precise insights into the film formation mechanisms and conformality performance across any deposition reaction system, from coupon-sized R&D to 300 mm wafer processes at the fab level. It is recommended to use the PillarHall test structure already during the process optimization stage, even before targeting uniform films on flat wafers.
By initiating HAR experiments early, many challenges that typically arise at later stages can be mitigated. Tuning the process from flat substrate films to HAR conformal films can be achieved by adjusting precursor dosages and pulse times, indirectly influencing reaction conditions and dynamics. Expectations should be set for the impact on film properties, which, in the worst case, may lead to wasted efforts in optimizing flat substrate processes. Moreover, HAR experiments and metrology offer a valuable and unique way to deepen understanding of the process window and tunability, which can also be applied during the flat substrate and wafer-level ramp-up phases later on.
Plasma-assisted and plasma-enhanced ALD/CVD processes enable lower deposition temperatures and improved throughput compared to conventional thermal processes in industrial processes. However, achieving conformal HAR deposition with plasma-assisted processes can be challenging due to the directional nature of the ionic species formed by plasma. The geometry of the HAR substrate significantly influences the performance of plasma-assisted processes. Nevertheless, the reaction mechanisms also involve plasma radicals, which can enhance conformality ([link and reference]). Pioneering work by TU Eindhoven has demonstrated the potential to fine-tune plasma ALD processes to achieve high conformality.
ALD is part of the rapidly evolving family of atomic layer processing technologies. Innovations in reactor design and applications, as well as combinations of ALD and CVD, offer significant opportunities to develop new methods and enhance control over film formation in high aspect ratio structures.
Spatial ALD is a film deposition technology that operates under ambient air and pressure conditions. These conditions pose fundamental challenges for achieving highly conformal films. Pioneering research by TU Eindhoven, utilizing PillarHall test structures, has demonstrated that spatial ALD processes can be finely tuned to meet HAR requirements.
Atomic Layer Etching (ALE) represents an emerging etching technology that operates inversely to ALD. PillarHall is compatible with ALE etching experiments, and the first demonstration was recently conducted by TU Dresden.
Surface cleaning and pre-treatment is also important topic. PillarHall, being entirely silicon-based, provides a foundation for multistep processing when the starting surface is single-crystal silicon with native oxide. Various pre-treatments can significantly impact film conformality and should always be considered as part of thin film experiments.
Area Selective Deposition (ASD) introduces another innovative approach within atomic layer processing, which may involve combinations of ALD and ALE or specific growth inhibitors. ASD aims to deposit films selectively on one patterned material while preventing deposition on other substrate areas, utilizing both surface topography and chemistry. Currently, PillarHall is best compatible to certain top membrane topographically controlled ASD studies. Additionally, Chipmetrics offers comprehensive ASD test chip and ASD test wafer design services.
1. PillarHall® LHAR4:
The PillarHall® LHAR4 is a cutting-edge metrology test structure, meticulously engineered for high aspect ratio (HAR) film deposition processes. This product enables precise measurement of film conformality, including thickness, composition, and other property distributions within HAR structures—without the need for cross-sectioning.
o Key Features:
Accurate Conformality Measurements: Offers rapid and precise measurement of film conformality and thickness
Troubleshooting Aid: Facilitates the identification and resolution of issues related to film deposition in HAR structures
o Benefits:
Enhanced Process Optimization: Plays a crucial role in refining process control and optimization, leading to more reliable production outcomes.
Accelerated Material and Process Development: Significantly speeds up the development and qualification phases for new materials and deposition processes, reducing time-to-market.
More information: Link to PillarHall page
2. Chipmetrics® VHAR1:
The Chipmetrics VHAR1 test structure features an array of vertical holes, specially designed to facilitate conventional ultra-high aspect ratio (UHAR) metrology through cross-sectional analysis. Ideal for applications that involve channel hole geometries, such as directional deposition and etch processes, the VHAR1 also serves as a complementary tool to the PillarHall when there is a need to focus more on 3D substrate geometry factors.
o Key Features:
Ultra-High Aspect Ratio Support: Optimized for advanced metrology in structures with extremely high aspect ratios.
Detailed Film Analysis: Enables in-depth analysis of film thickness and conformality in vertical high aspect ratio geometries.
Complex Structure Evaluation: Assists in the detailed evaluation of deposition and etching processes in complex structures.
More information: Link to VHAR1 page.
3. Measurement service
Comprehensive Metrology Solutions
Customers can send their PillarHall samples to us, and we will conduct detailed measurements of the film penetration depth profile as a service. Utilizing our state-of-the-art laboratory facilities, we provide precise and reliable metrology services that cater specifically to the needs of our customers.
Service Highlights:
• Expert Analysis: Our advanced laboratory is equipped with the latest technology to deliver accurate and comprehensive film depth profiling.
• Convenience: Clients simply send their samples, and our experts handle all aspects of the measurement process.
• Custom Reports: Each measurement service is concluded with a detailed report, providing insights that are critical for process optimization and quality control.
One of the most unique features of the PillarHall LHAR approach is the ability to measure the chemical and elemental composition of films on HAR sidewalls as a function of film penetration depth. Useful analytical instruments include XPS, ToF-SIMS, SEM/EDX, Raman spectroscopy, and imaging ellipsometers. Additionally, scanning probe methods prove valuable as they allow for the mapping of film properties such as electrical, magnetic, mechanical, and wetting characteristics through variable probes. The main requirement is that the measurement spot or pixel size must be sufficiently small, and the instrument must be capable of operating in line-scan or imaging mode.
The mapping of elemental and other properties of the film on the HAR sidewall provides a more accurate understanding of film conformality. It also aids in identifying potential issues in device functionality and tracing these problems back to the film manufacturing process.
By initiating HAR experiments early, many challenges that typically arise at later stages can be mitigated. Tuning the process from flat substrate films to HAR conformal films can be achieved by adjusting precursor dosages and pulse times, indirectly influencing reaction conditions and dynamics. Expectations should be set for the impact on film properties, which, in the worst case, may lead to wasted efforts in optimizing flat substrate processes. Moreover, HAR experiments and metrology offer a valuable and unique way to deepen understanding of the process window and tunability, which can also be applied during the flat substrate and wafer-level ramp-up phases later on.
Plasma-assisted and plasma-enhanced ALD/CVD processes enable lower deposition temperatures and improved throughput compared to conventional thermal processes in industrial processes. However, achieving conformal HAR deposition with plasma-assisted processes can be challenging due to the directional nature of the ionic species formed by plasma. The geometry of the HAR substrate significantly influences the performance of plasma-assisted processes. Nevertheless, the reaction mechanisms also involve plasma radicals, which can enhance conformality ([link and reference]). Pioneering work by TU Eindhoven has demonstrated the potential to fine-tune plasma ALD processes to achieve high conformality.
ALD is part of the rapidly evolving family of atomic layer processing technologies. Innovations in reactor design and applications, as well as combinations of ALD and CVD, offer significant opportunities to develop new methods and enhance control over film formation in high aspect ratio structures.
Spatial ALD is a film deposition technology that operates under ambient air and pressure conditions. These conditions pose fundamental challenges for achieving highly conformal films. Pioneering research by TU Eindhoven, utilizing PillarHall test structures, has demonstrated that spatial ALD processes can be finely tuned to meet HAR requirements.
Atomic Layer Etching (ALE) represents an emerging etching technology that operates inversely to ALD. PillarHall is compatible with ALE etching experiments, and the first demonstration was recently conducted by TU Dresden.
Surface cleaning and pre-treatment is also important topic. PillarHall, being entirely silicon-based, provides a foundation for multistep processing when the starting surface is single-crystal silicon with native oxide. Various pre-treatments can significantly impact film conformality and should always be considered as part of thin film experiments.
Area Selective Deposition (ASD) introduces another innovative approach within atomic layer processing, which may involve combinations of ALD and ALE or specific growth inhibitors. ASD aims to deposit films selectively on one patterned material while preventing deposition on other substrate areas, utilizing both surface topography and chemistry. Currently, PillarHall is best compatible to certain top membrane topographically controlled ASD studies. Additionally, Chipmetrics offers comprehensive ASD test chip and ASD test wafer design services.
1. PillarHall® LHAR4:
The PillarHall® LHAR4 is a cutting-edge metrology test structure, meticulously engineered for high aspect ratio (HAR) film deposition processes. This product enables precise measurement of film conformality, including thickness, composition, and other property distributions within HAR structures—without the need for cross-sectioning.
o Key Features:
Accurate Conformality Measurements: Offers rapid and precise measurement of film conformality and thickness
Troubleshooting Aid: Facilitates the identification and resolution of issues related to film deposition in HAR structures
o Benefits:
Enhanced Process Optimization: Plays a crucial role in refining process control and optimization, leading to more reliable production outcomes.
Accelerated Material and Process Development: Significantly speeds up the development and qualification phases for new materials and deposition processes, reducing time-to-market.
More information: Link to PillarHall page
2. Chipmetrics® VHAR1:
The Chipmetrics VHAR1 test structure features an array of vertical holes, specially designed to facilitate conventional ultra-high aspect ratio (UHAR) metrology through cross-sectional analysis. Ideal for applications that involve channel hole geometries, such as directional deposition and etch processes, the VHAR1 also serves as a complementary tool to the PillarHall when there is a need to focus more on 3D substrate geometry factors.
o Key Features:
Ultra-High Aspect Ratio Support: Optimized for advanced metrology in structures with extremely high aspect ratios.
Detailed Film Analysis: Enables in-depth analysis of film thickness and conformality in vertical high aspect ratio geometries.
Complex Structure Evaluation: Assists in the detailed evaluation of deposition and etching processes in complex structures.
More information: Link to VHAR1 page.
3. Measurement service
Comprehensive Metrology Solutions
Customers can send their PillarHall samples to us, and we will conduct detailed measurements of the film penetration depth profile as a service. Utilizing our state-of-the-art laboratory facilities, we provide precise and reliable metrology services that cater specifically to the needs of our customers.
Service Highlights:
• Expert Analysis: Our advanced laboratory is equipped with the latest technology to deliver accurate and comprehensive film depth profiling.
• Convenience: Clients simply send their samples, and our experts handle all aspects of the measurement process.
• Custom Reports: Each measurement service is concluded with a detailed report, providing insights that are critical for process optimization and quality control.
Chipmetrics is a leader in the semiconductor 3D metrology, offering cutting-edge solutions for process control through its innovative test chips and wafers.
Our core technologies provide a new perspective in measuring 3D thin films within high aspect ratio device architectures, enabling precise and rapid assessments crucial for development and manufacturing.
We specialize in assisting our clients to develop new materials, optimize deposition processes, and enhance overall yields, significantly accelerating their time to market.
ISO 9001:2015 compliant. IC cleanliness certified
Country of origin: Finland, EU
Registered exporter FIREX31010316
Address: Yliopistokatu 7, Photonics center
80130, Joensuu, Finland
phone: +358 10 348 1344
E-mail: [email protected]
