Günther Hans Derra

Optimised Light Sources for Projection Displays

The fast developments in projection display technology require a corresponding development of short arc lamps. Arc length and high luminance determine light collection rather than lamp power. The new UHP lamps combine highest brightness, extremely long life and system compactness.

Sn DPP source-collector modules: status of alpha resources, beta developments, and the scalability to HVM

For industrial EUV (extreme ultra-violet) lithography applications high power extreme ultraviolet (EUV) light sources are needed at a central wavelength of 13.5 nm, targeting 32 nm node and below. Philips Extreme UV GmbH and XTREME technologies GmbH have developed DPP (Discharge Produced Plasma) Alpha tools which run in operation at several locations in the world. In this paper the status of the Alpha Sn-DPP tools as developed by Philips Extreme UV GmbH will be given. The Alpha DPP tools provide a good basis for the development and engineering of the Beta tools and in the future of the HVM tools. The first Beta source has been designed and first light has been produced. Engineering steps will folow to optimize this first generation Beta Sn-DPP source. HVM tools target EUV power levels from 200W to 500W in IF. In this paper we show that the power requried for HVM can be generated with Sn-DPP sources. Based on Alpha Sn-DPP sources we show that repetition frequency and generated EUV pulse energy is scalable up to power levels that match the HVM requirements.

52.1: Invited Paper: New Developments in Projection Light Sources—Shorter Arcs and Miniaturisation

New developments of UHP lamps with higher power and shorter arcs (even below 1mm) fulfill the optical demands of future projectors and novel displays. In addition a new technology is presented which leads to a reduction of the lamp ignition voltage from 20kV to 5kV. This enables a further step in system size reduction.

EUV sources for the alpha-tools

In this paper, we report on the recent progress of the Philips Extreme UV source. The Philips source concept is based on a discharge plasma ignited in a Sn vapor plume that is ablated by a laser pulse. Using rotating electrodes covered with a regenerating tin surface, the problems of electrode erosion and power scaling are fundamentally solved. Most of the work of the past year has been dedicated to develop a lamp system which is operating very reliably and stable under full scanner remote control. Topics addressed were the development of the scanner interface, a dose control system, thermo-mechanical design, positional stability of the source, tin handling, and many more. The resulting EUV source-the Philips NovaTin(R) source-can operate at more than 10kW electrical input power and delivers 200W in-band EUV into 2π continuously. The source is very small, so nearly 100% of the EUV radiation can be collected within etendue limits. The lamp system is fully automated and can operate unattended under full scanner remote control. 500 Million shots of continuous operation without interruption have been realized, electrode lifetime is at least 2 Billion shots. Three sources are currently being prepared, two of them will be integrated into the first EUV Alpha Demonstration tools of ASML. The debris problem was reduced to a level which is well acceptable for scanner operation. First, a considerable reduction of the Sn emission of the source has been realized. The debris mitigation system is based on a two-step concept using a foil trap based stage and a chemical cleaning stage. Both steps were improved considerably. A collector lifetime of 1 Billion shots is achieved, after this operating time a cleaning would be applied. The cleaning step has been verified to work with tolerable Sn residues. From the experimental results, a total collector lifetime of more than 10 Billion shots can be expected.

Xenon DPP Source Technologies for EUVL Exposure Tools

The learning gained in previous developments for EUV Micro Exposure and Alpha Tools builds the basis for the EUVL source development at XTREME technologies and Philips EUV. Field data available from operation of these tools are in use for continuous improvements in core technology areas such as plasma generation and forming, component reliability, debris mitigation and optical performance. Results from integration and operation of alpha tool sources are presented in the areas power performance, component lifetime and debris mitigation efficiency. The analysis results and simulation work of the realized EUV source concept are discussed and innovative concepts for component and module improvements are introduced. The technological limit for the Xenon based sources seems to be reached on alpha performance level. Therefore the next EUV source generations are based on Tin to increase the efficiency and full performance of those sources. For the Betatool and HVM source generations a joint development work between XTREME technologies and Philips EUV is introduced. The related work is content of another presentation of this conference.

9.1: Arc Stabilisation for Short Arc Projection Lamps

UHP-lamps are standard for high efficient projection systems. All short arc lamps show arc instabilities. Optical integrators can successfully suppress visual effects but they are of limited use for small displays. A new technology is presented here which stabilises the lamp arc directly and keeps the good maintenance of the lamp.

Invited Paper: UHP‐lamp systems for projection applications

— Projection systems have found widespread use in conference rooms and other professional applications during the last decade and are now entering the home-TV market with considerable pace. Projectors as small as about one liter are nowadays able to deliver a screen flux of several thousand lumens and are, with a system efficacy of more than 10 lm/W, the most-efficient display system realized today. Because such highly efficient projectors employ microdisplays as light valves, short-arc lamps are a key component in realizing these properties. The introduction of the UHP-lamp system by Philips in 1995 can be identified as one of the key enablers for the commercial success of projection systems. The ultra-high-performance (UHP) lamp concept features outstanding arc luminance, a well-suited spectrum, long life, and excellent flux maintenance. For the first time, it combines a very-high-pressure mercury-discharge lamp having an extremely short and stable arc length with a regenerative chemical cycle that keeps the discharge walls free from blackening, leading to lifetimes of over 10,000 hours. In this review, the most important aspects of the UHP concept that enabled its success in the projection market are described, followed by a discussion of some recent additions to the UHP-product portfolio.