This chapter describes the development of a laser-produced-plasma (LPP) EUV source for advanced lithography applications in high-volume manufacturing (HVM) of semiconductor devices. EUVL is expected to succeed 193-nm immersion multipatterning technology for sub-10-nm critical-layer patterning. The most recent results from high-power systems targeted at the 250-W configuration are described to date. The requirements and technical challenges related to successful implementation of these technologies are outlined for the reader. Development of second-generation LPP light sources for ASML's NXE:3300B, NXE:3350B, and NXE:3400B (Fig. 3A.1) EUV scanners is complete, with approximately 15 units installed and operational at chipmaker customers. Different aspects and performance characteristics of the sources as well as related research and development progress at our facilities were already described in detail in several earlier publications. We have described initial dose stability results, power scaling and availability data for ASML's NXE:3100 first-generation sources, and have reported on several new development results. Ten first-generation NXE:3100 sources (Fig. 3A.2) have been operational for over five years; five systems were deployed to customers for use in process development at early adopters of EUVL technology. Key features of the NXE platform as well as scanner performance during the system introduction have already been reviewed in detail. In this chapter, we report on the characterization of source components that are critical to achieve the higher power required for the second-generation light sources to support EUV scanners at chipmaker production facilities. The NXE:3300B source drive laser uses a master oscillator power amplifier (MOPA) laser architecture with a pre-pulse mode of operation. The pre-pulse conditions the target from a liquid tin (Sn) droplet to a lower-density target at the focal plane of the laser focusing optics. A main (high-energy) pulse from the drive laser is then focused onto the prepulse-conditioned target, creating a highly ionized plasma that emits EUV radiation at wavelengths around 13.5 nm.

A novel method of modeling Sn (tin) scattering through H2 (molecular hydrogen) is examined. Density-functional theory (DFT) software from the Amsterdam Modeling Suite was used to determine the interaction energy of Sn and H2 at varying spacing and orientations. This data was used to generate a function that describes the average interaction energy with respect to distance between the two species for neutral Sn as well as selected Sn ionized states. These resulting functions were inserted into RustBCA, a binary collision approximation code for ion-material interactions. The scattering of a Sn beam through H2 was modeled for each newly generated potential, along with well-known potentials such as ZBL and Moliere for comparison. Legacy software, such as TRIM, is not capable of modeling scattering using potentials that contain attractive components. The potentials generated with DFT have attractive components, so this analysis is only possible now using RustBCA. This method can give more accurate results than previous work. A model using the ZBL potential wherein a neutral Sn beam of 10 keV scattered through 15 cm of H2 left 87.8% of the Sn atoms within 41.4 millisteradians of the primary axis and an average energy of 816.3 eV ± 8.71 eV. The same model with a DFT-generated potential gives a much narrower particle distribution with higher average energies. This modeling work will also be compared against ongoing experimental measurements of Sn ions through H2 for further comparison.

Multiple ASML NXE:3400C scanners are installed at customer factories and being used in high volume manufacturing (HVM) of leading semiconductor devices. The latest generation of NXE:3400C sources has improved performance and availability by implementing a modular vessel concept and an automated tin supply system. In this paper, we provide an overview of 13.5 nm tin laser-produced-plasma (LPP) extreme-ultraviolet (EUV) sources enabling HVM at the N5 node and beyond. The field performance of sources operating at 250 watts power including the performance of subsystems such as the Collector and the Droplet Generator will be shown. Progress in the development of key technologies for power scaling towards 420W will be described.

Over 50 EUV scanners are installed at customer factories and being used in high volume manufacturing (HVM) of leading semiconductor devices. The latest generation of EUV sources are operating at 250W while meeting all other requirements. Future EUV scanners are projected to require more stable EUV and higher powers >600W to meet throughput requirements. In this paper, we provide an overview of a the latest advances in the laboratory for tin laser-produced-plasma (LPP) extreme-ultraviolet (EUV) sources at 13.5nm enabling HVM at the N5 node and beyond, highlighting crucial EUV source technology developments needed to meet future requirements for EUV power and stability. This includes the performance of subsystems such as the Collector and the Droplet Generator.

A hydrogen plasma cleaning technique to clean Sn (tin) off EUV collector optics is studied in detail. The cleaning process uses hydrogen radicals and ions (formed in the hydrogen plasma) to interact with Sn-coated surfaces, forming SnH 4 and being pumped away. This technique has been used to clean a 300mm-diameter stainless steel dummy collector optic, and EUV reflectivity of multilayer mirror samples was restored after etching Sn from them. Previous experiments have shown etch rates of greater than 10 nm/min over a 2 inch diameter circular plasma area with an SWP launcher. An etch experiment was conducted with a sweep over sample bias to investigate the influence of hydrogen ions. Radial etch rates for each hydrogen ion energy were measured using profilometry. Langmuir probe and radical measurements were also taken. Langmuir probe measurements of the surface wave plasma show a two temperature distribution for electrons: a bulk temperature of 2.3 eV and some population at 8.6 eV. The bulk electron density was measured to be 2.7e11 cm -3 . Radical probe measurements give the hydrogen radical density at 1.96e15 cm -3 . A COMSOL model of this experiment was also built and simulation results will be presented. In this work, experiments elucidating the fundamental processes of tin removal are conducted by varying pressure, power, surface temperature and gas flow rate. The ion bombardment reduces the number of radicals needed to etch a single tin atom to the range of -. The linear SWP antenna yields plasma densities on the order of and radical densities on the order of , allowing for greater utilization of ion etch enhancement. Etch rates of up to 200 nm/min have been achieved. The surface temperature of the samples is an important factor in the etching process such that decrease of the surface temperature increases the etch rates and decreases the hydrogen desorption rates. In addition, a kinetic etch model is developed to explain the behavior of the etch rates as function of the surface temperature. Furthermore, results from experiments performed in Illinois NXE:3100 chamber will be discussed.

Over 85 EUV scanners are installed at customer factories and being used in high volume manufacturing (HVM) of leading semiconductor devices. The latest generation of EUV sources are operating at 250W with 92% availability, while meeting all performance requirements. Future EUV scanners are projected to require even higher power to meet throughput requirements. In this paper, we provide an overview of a the latest advances in the laboratory for tin laser-produced-plasma (LPP) extreme-ultraviolet (EUV) sources at 13.5nm enabling HVM at the N5 node and beyond, highlighting crucial EUV source technology developments needed to meet future requirements for EUV power and stability. This includes the performance of subsystems designed for critical source functions such as collector protection and continuous tin droplet supply.

Multiple ASML’s NXE:3400B scanners are installed at the factories and slated to go to a high volume manufacturing (HVM) phase. The latest generation of the scanners NXE:3400C has an improved performance and availability also due to availability improvement of the EUV sources by implementing modularity concept. In this paper, we provide an overview of a tin laser-produced-plasma (LPP) extreme-ultraviolet (EUV) sources at 13.5nm enabling HVM at the N7 node and beyond. The field performance of the source at 250 watts power including the performance of subsystems such as the Collector and the Droplet Generator will be shown. Progress in the development of key technologies for power scaling towards 500W will be described.

This year, we expect EUV lithography to succeed 193 nm immersion multi-patterning technology for sub-10 nm critical layer patterning. In order to be successful, the EUV lithography source has to de...

In this paper, we provide an overview of state-of-the-art technologies for incoherent laser-produced tin plasma extreme-ultraviolet (EUV) sources at 13.5nm with performance enabling high volume semiconductor manufacturing (HVM). The key elements to development of a stable and reliable source that also meet HVM throughput requirements and the technical challenges for further scaling EUV power to increase productivity are described. Improvements in availability of droplet generation and the performance of critical subsystems that contribute to EUV collection optics lifetime toward the one tera-pulse level, are shown. We describe current research activities and provide a perspective for EUV sources towards the future ASML Scanners.

In this paper, we provide an overview of various technologies for scaling tin laser-produced-plasma (LPP) extremeultraviolet (EUV) source performance to enable high volume manufacturing (HVM). We will show improvements to source architecture that facilitated the increase of EUV power from 100W to 250W, and the technical challenges for power scaling of key source parameters and subsystems. The performance of critical subsystems such as the Droplet Generator and Collector protection will be shown, with emphasis on stability and lifetime. Finally, we will describe current research activities and provide a perspective for LPP EUV sources towards 500W.

We provide an overview of laser-produced-plasma (LPP) extreme-ultraviolet (EUV) source performance to enable high volume manufacturing and improvements in various technologies for scaling output power of the source. Several companies have multiple systems and are ramping toward production, we will show current output and availability of sources and describe their readiness for HVM. We will show improvements to source architecture that facilitated the increase of EUV power to 250W, and the technical challenges for power scaling of key source parameters and subsystems. The performance of critical subsystems such as the Droplet Generator and Collector protection will be shown, with emphasis on stability and lifetime. Finally, we will describe current research activities and provide a perspective for LPP EUV sources towards 500W.

In this paper, we provide an overview of various challenges and their solutions for scaling laser-produced-plasma (LPP) extreme-ultraviolet (EUV) source performance to enable high volume manufacturing. We will discuss improvements to source architecture that facilitated the increase of EUV power from 100W to >200W, and the technical challenges for power scaling of key source parameters and subsystems. Finally, we will describe current power-scaling research activities and provide a forward looking perspective for LPP EUV sources towards 500W.

Extreme ultraviolet (EUV) lithography is expected to succeed in 193-nm immersion multi-patterning technology for -sub-10-nm critical layer patterning. In order to be successful, EUV lithography has to demonstrate that it can satisfy the industry requirements in the following critical areas: power, dose stability, etendue, spectral content, and lifetime. Currently, development of second-generation laser-produced plasma (LPP) light sources for the ASML's NXE: 3300B EUV scanner is complete, and first units are installed and operational at chipmaker customers. We describe different aspects and performance characteristics of the sources, dose -stability results, power scaling, and availability data for EUV sources and also report new development results.

ASML is committed to develop high power EUV source technology for use in EUV lithography for high-volume-manufacturing (HVM) of semiconductors. A stable dose controlled Laser-Produced-Plasma (LPP) EUV source has been successfully developed and introduced using a CO2 laser and small tin (Sn) droplets.

NXE:3300B scanners have been operational at customer sites since almost two years, and the NXE:3350B, the 4th generation EUV system, has started shipping at the end of 2015. All these exposure tools operate using MOPA pre-pulse source technology, which enabled significant productivity scaling, demonstrated at customers and at ASML. Having achieved the required throughput to support device development, the main priority of the ASML EUV program has shifted towards improving stability and availability. Continuous progresses in defectivity reduction and in the realization of a reticle pellicle are taking place at increased speed. Today's overlay and imaging results are in line with the requirements of 7nm logic devices; Matched Machine overlay to ArF immersion below 2.5 nm and full wafer CDU performance of less than 1.0nm are regularly achieved. The realization of an intensity loss-less illuminator and improvements in resist formulation are significant progress towards enabling the use of EUV technology for 5nm logic devices at full productivity. This paper will present an overview of the status of the ASML EUV program and product roadmap by reviewing the current performance and on-going developments in productivity, imaging, overlay and mask defectivity reduction.

We present highlights from plasma simulations performed in collaboration with Lawrence Livermore National Labs. This modeling is performed to advance the rate of learning about optimal EUV generation for laser produced plasmas and to provide insights where experimental results are not currently available. The goal is to identify key physical processes necessary for an accurate and predictive model capable of simulating a wide range of conditions. This modeling will help to drive source performance scaling in support of the EUV Lithography roadmap. The model simulates pre-pulse laser interaction with the tin droplet and follows the droplet expansion into the main pulse target zone. Next, the interaction of the expanded droplet with the main laser pulse is simulated. We demonstrate the predictive nature of the code and provide comparison with experimental results.

Cymer-ASML is committed to develop high power EUV source technology based on CO2 laser-produced-plasma (LPP) for use in EUV lithography for high-volume-manufacturing of semiconductors. Stable dose controlled EUV power at intermediate focus (IF) has been successfully developed using a CO2 laser of high intensity, short pulse duration, high repetition, and high average power. Figure 1 shows 185 W at Intermediate Focus (IF) dose-controlled EUV source power and dose stability over a one hour demonstration. EUV pulse energy up to 5 mJ with 22% overhead is created at 50 kHz. Dose error is all smaller than 1%. This enables 100% good dies exposure.

Multiple NXE:3300 are operational at customer sites. These systems, equipped with a Numerical Aperture (NA) of 0.33, are being used by semiconductor manufacturers to support device development. Full Wafer Critical Dimension Uniformity (CDU) of 1.0 nm for 16nm dense lines and 1.1 nm for 20nm isolated space and stable matched overlay performance with ArF immersion scanner of less than 4nm provide the required lithographic performance for these device development activities. Steady progresses in source power have been achieved in the last 12 months, with 100Watts (W) EUV power capability demonstrated on multiple machines. Power levels up to 90W have been achieved on a customer machine, while 110W capability has been demonstrated in the ASML factory. Most NXE:3300 installed at customers have demonstrated the capability to expose 500 wafers per day, and one field system upgraded to the 80W configuration has proven capable of exposing 1,000 wafers per day. Scanner defectivity keeps being reduced by a 10x factor each year, while the first exposures obtained with full size EUV pellicles show no appreciable difference in CDU when compared to exposures done without pellicle. The 4th generation EUV system, the NXE: 3350, is being qualified in the ASML factory.

This paper describes the development and evolution of the critical architecture for a laser-produced-plasma (LPP) extreme-ultraviolet (EUV) source for advanced lithography applications in high volume manufacturing (HVM). In this paper we discuss the most recent results from high power sources in the field and testing on our laboratory based development systems, and describe the requirements and technical challenges related to successful implementation of those technologies on production sources. System performance is shown, focusing on pre-pulse operation with high conversion efficiency (CE) and with dose control to ensure high die yield. Finally, experimental results evaluating technologies for generating stable EUV power output for a high volume manufacturing (HVM) LPP source will be reviewed.

Laser produced plasma (LPP) light sources have been developed as the primary approach for EUV scanner imaging of circuit features in sub-20nm devices in high volume manufacturing (HVM). This paper provides a review of development progress and readiness status for the LPP extreme-ultra-violet (EUV) source. We present the latest performance results from second generation sources, including Prepulse operation for high power, collector protection for long lifetime and low cost of ownership, and dose stability for high yield. Increased EUV power is provided by a more powerful drive laser and the use of Prepulse operation for higher conversion efficiciency. Advanced automation and controls have been developed to provide the power and energy stability performance required during production fab operation. We will also discuss lifetesting of the collector in Prepulse mode and show the ability of the debris mitigation systems to keep the collector multi-layer coating free from damage and maintain high reflectivity.