TEUS - LPP EUV light source with high brightness and low debris
LPP EUV source is based on fast rotating liquid metal target. A novel LPP target with conventional debris mitigation techniques has resulted in an ultimate solution for a clean photon EUV source.
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Fast rotation target provides:-Redirection of droplet debris away from input (laser) and output (EUV) windows -Undisturbed target surface for a high rep rate laser system (up to 1 MHz) -Minimum synchronisation required as the target is continuous -Excellent inherent source spatial stability |
High rotation speed allows drastic changes in angular velocity distribution for droplets with initial velocities comparable with linear velocity of the target (Key elements, general principles and techniques protected by granted patents)
| Actinic source TEUS | EUV collection angle, sr | Laser average power, W | Pulse duration, ns | Pulse frequency, kHz | Plasma size, µm | Brightness*, W/mm2sr | EUV power**, mW | Collector lifetime***, % |
| s100 | 0.05 | 100 | 1.5 | 25 | 60 | 100 | 5 | >1year |
| s200 | 0.05 | 200 | 1.5 | 50 | 60 | 200 | 10 | >0.5year |
| s400 | 0.05 | 400 | 1.5 | 100 | 60 | 400 | 20 | >0.2year |
| Actinic source TEUS | EUV collection angle, sr | Laser average power, W | Pulse duration, ns | Pulse frequency, kHz | Plasma size, µm | Brightness*, W/mm2sr | EUV power**, mW | Collector lifetime***, % |
| M100 | 0.15 | 100 | 1.5 | 25 | 60 | 100 | 15 | >1year |
| M200 | 0.15 | 200 | 1.5 | 50 | 60 | 200 | 30 | >0.5year |
| M400 | 0.15 | 400 | 1.5 | 100 | 60 | 400 | 60 | >0.2year |
All parameters are for in-band (13.5 nm ± 1%) radiation. Conversion efficiency for in-band radiation is 2%@2π. For full-band (13.5 nm ± 2%) conversion efficiency is 4%@2π, allowing to double brightness and the collected EUV power
*- at the plasma for different source sizes of 30-60um (where the higher brightness corresponds to the smaller spot size)
**- after collection mirror.
***- time of 10% loss of reflectivity
With the use of a replaceable membrane it is possible to prevent any particles from reaching the compartment which contains the reticle, pellicle and any sensitive elements