We are developing a CO2 laser driven Tin plasma EUV source for HVM EUVL. This approach enables cost-effective EUV power scaling by high-conversion efficiency and full recovery of Tin fuel. The RF-excited, multi 10 kW average power pulsed CO2 laser system is a MOPA (master oscillator power amplifier) configuration and operates at 100 kHz with 20 ns pulse width. The EUV light source is scalable to in-band 200 W IF power with a single 20-kW CO2 laser beam. EUV chamber is kept uncontaminated by using a small size droplet target and effective Tin exhaust by magnetic plasma guiding. Characterization of the plasma flow in uniform magnetic field was studied by monitoring the motion of Tin plasma stream in a large vacuum chamber, depending on the magnetic flux up to 2 T. Topics relevant for HVM source is reported on continuous operation and Tin vapor evacuation.
We are developing a Sn droplet generator for a LPP HVM EUV light source. Droplet trains with frequencies up to 500kHz and droplet diameters below 20um are generated via the continuous jet method. Charging single droplets and using deflector electrodes these charged droplets are selected from the droplet train and irradiated by the drive laser. Due to the small droplet diameter, the drive laser otherwise irradiates several droplets inside the droplet train thus increasing the Sn debris as is experimentally shown. In addition, the paper outlines that a 30um droplet size is the mass limit for up to 180W EUV generation based on the assumption that each Sn atom emits on average a single in-band photon.
We are developing a laser produced plasma light source for high volume manufacturing (HVM) EUV lithography. The
light source is based on a high power, high repetition rate CO2 laser system, a tin target and a magnetic ion guiding for
tin treatment. The laser system is a master oscillator power amplifier (MOPA) configuration. We have achieved an
average laser output power of 10 kW at 100 kHz by a single laser beam with good beam quality. EUV in-band power
equivalent to 60 W at intermediate focus was produced by irradiating a tin rotating plate with 6 kW laser power. This
light source is scalable to more than 200 W EUV in-band power based on a 20-kW CO2 laser. Collector mirror life can
be extended by using droplet target and magnetic ion guiding. Effectiveness of the magnetic ion guiding is examined by
monitoring the motion of fast Sn ion in a large vacuum chamber with a maximum magnetic flux density of 2 T.
We are developing a laser produced plasma light source for high volume manufacturing (HVM) EUV lithography. The
light source is based on a short pulse, high power, high repetition rate CO2 master oscillator power amplifier (MOPA)
laser system and a Tin droplet target. A maximum conversion efficiency of 4.5% was measured for a CO2 laser driven Sn
plasma having a narrow spectrum at 13.5 nm. In addition, low debris generation was observed. The CO2 MOPA laser
system is based on commercial high power cw CO2 lasers. We have achieved an average laser power of 7 kW at 100 kHz
by a single laser beam with good beam quality. In a first step, a 50-W light source is under development. Based on a 10-kW CO2 laser, this light source is scalable to more than 100 W EUV in-band power.
We evaluated Sn debris generated from a CO2 laser (10.um) and a Nd:YAG laser (1064nm) plasma. Experiments were
performed with bulk Sn-plates (t=1mm) and freestanding Sn-foils (t=15um). Quartz Crystal Microbalances (QCM) were
used for debris analysis. We observed a drastically lower deposition for the CO2 laser driven plasma compared with the
Nd:YAG laser plasma. In addition, several Sn coated targets with different Sn thickness were investigated for the CO2
drive laser with respect to the generated plasma debris. In general, a 100nm Sn coated glass target generated more debris
than the solid Sn target. Especially, we observed for the Sn-plate target that the deposition rate is smaller than the erosion
(sputter) rate caused by the plasma ions.
We develop a laser produced plasma light source for high volume manufacturing (HVM) EUV lithography. The light
source is based on a short pulse, high power, high repetition rate CO2 master oscillator power amplifier (MOPA) laser
system and a Tin droplet target. A maximum conversion efficiency of 4.5% was measured for a CO2 laser driven Sn
plasma having a narrow spectrum at 13.5 nm. In addition, low debris generation was observed. The CO2 MOPA laser
system is based on commercial high power cw CO2 lasers. We achieve an average laser power of 3 kW at 100 kHz with a
single laser beam that has very good beam quality. In a first step, a 50-W light source is developing. Based on a 10-kW
CO2 laser this light source is scalable to more than 100 W EUV in-band power.
A CO2 laser driven Xe droplet plasma is presented as a light source for EUV lithography. A short-pulse TEA CO2 master oscillator power amplifier system and a pre-pulse Nd:YAG laser were used for initial experiment with 0.6% of CE from a Xe jet. A target technology is developed for high average power experiments based on a Xe droplet at 100kHz. Magnetic field ion mitigation is shown to work well in the pre-pulsed plasma combined with a CO2 laser main pulse. This result is very promising with respect to collector mirror lifetime extension by magnetic field mitigation. A master oscillator power amplifier (MOPA) CO2 laser system is under development with a few kW and 100 kHz repetition rate with less than 15ns laser pulse width using a waveguide Q-switched CO2 laser oscillator and RF-excited fast axial flow CO2 laser amplifiers.
The status of the next generation lithography laser produced plasma light source development at EUVA is presented. The light source is based on a Xenon jet target and a Nd:YAG driver laser. The laser, having a master oscillator power amplifier (MOPA) configuration, operates at 10 kHz repetition rate and generates an average output power of 1.5 kW. The fwhm pulsewidth is 6 ns. The EUV system currently delivers an average EUV source power of 9.1 W (2% bandwidth, 2π sr) with a conversion efficiency of 0.6 %. Based on the development it is concluded that solid-state Nd:YAG laser technology can be cost efficiently used to produce 10 W level EUV light sources. In order to generate an average power of 115 W for a future extreme ultraviolet (EUV) light source, however, the cost of a Nd:YAG based LPP source will be too high. Therefore RF-CO2 laser technology will be used. The designed CO2 driver laser system has a MOPA configuration. The oscillator has ns-order pulsewidth and the laser system operates at a repetition rate of 100 kHz. Due to its inert cleanliness Xenon droplets will be the target material.
The main technological challenge of a future extreme ultraviolet (EUV) light source is the required average power of 115W at the intermediate focus. High repetition rate laser produced plasma (LPP) sources are very promising to face this challenge. We report the current status of the laser produced light source system we started to develop in 2002. The system consists of the following main components: The plasma target is a liquid xenon jet with a maximum diameter of 50 μm and a velocity of more than 30 m/s. A Nd:YAG laser oscillating at 1064 nm produces the plasma. The laser is a master oscillator power amplifier (MOPA) configuration with a maximum repetition rate of 10 kHz and an average power of 1.3kW. The EUV system currently delivers an average EUV in-band power of 7.2 W (2% bandwidth, 2π sr). In order to decrease debris and to reduce the supply of target material we started the development of a xenon droplet target. Currently droplets are generated in vacuum at a frequency of 140 kHz, i.e. 140000 droplets/s, having a diameter of 100 μm and a velocity of 28m/s.
The main technological challenge of a future extreme ultraviolet (EUV) light source is the required average power of
115W at the intermediate focus. High repetition rate laser produced plasma (LPP) sources are very promising to face
this challenge. We report the current status of the laser produced light source system we started to develop in 2002. The
system consists of the following main components: The plasma target is a liquid xenon jet with a maximum diameter of
50 micrometer and a velocity of more than 30 m/s. A Nd:YAG laser oscillating at 1064 nm produces the plasma. The
laser is a master oscillator power amplifier (MOPA) configuration with a maximum repetition rate of 10 kHz and an
average power of 1kW. The EUV system currently delivers an average EUV in-band power of 4 W (2% bandwidth, 2π
sr) having a stability of 0.54 % (1σ, 50-pulse moving average). In order to evaluate a further increase of the repetition
rate, xenon jet characteristics and EUV plasma images have been investigated at 10 kHz. In addition, a conversion
efficiency of 0.67% (2% bw, 2π sr) has been obtained at low repetition rate operation. This paper presents the progress
of our LPP light source development.
The roadmap of semiconductor fabrication predicts that the semiconductor market will demand 65 nm node devices from 2004/2005. Therefore, an Ultra-Line-Narrowed F2 laser for dioptric projection systems is currently being developed under the ASET project of The F2 Laser Lithography Development Project. The target of this project is to achieve a F2 laser spectral bandwidth below 0.2 pm (FWHM) and an average power of 25 W at a repetition rate of 5 kHz. The energy stability (3-sigma) target is less than 10%. An Oscillator-Amplifier arrangement at 2 kHz was developed as a first step of an Ultra-Line-Narrowed F2 laser system. With this laser system, we did the basic study of the synchronization technology for line narrowing operation using two system arrangements: MOPA (Master Oscillator/Power Amplifier) and Injection Locking. Based on this experience we have developed the 5 kHz system. With the 5 kHz Line-Narrowed Injection Locking system, we have achieved a spectral bandwidth of < 0.2 pm with an output energy of > 5 mJ and an energy pulse to pulse stability of 10%. The feasibility of a 5 kHz Ultra-Line-Narrowed F2 Laser for Dioptric Projection Systems has been demonstrated.
In the semiconductor industry, it is one of the most important issues to reduce manufacturing cost of the semiconductor device by increasing throughput. We have succeeded in the development of the high repetition rate excimer laser technology, and obtained the prospect of low CoO of the laser device. In this paper, we present the performance and advanced technologies of the newest model of the KrF excimer laser for microlithography; KLES-G20K. The laser achieves 20 W of output power with 0.6 pm bandwidth at 2 kHz. The pulse to pulse energy stability, 3 sigma is less than 6 percent and integrated energy stability is within +/- 0.4 percent. By our estimation, more than 50 percent of CoO of the laser device is cut by adopting developed machine compared to a present one.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.