Efficient Narrow Spectral Width Soft X-Ray Discharge Sources

Methods for making pulsed and continuous discharge plasma light sources for extreme ultraviolet(EUV) projection lithography and soft-x-ray microscopy as well as other applications are disclosed. A first light source of doubly ionized lithium ions emits over a narrow bandwidth of approximately 13.5 nm. A second light source of beryllium ions radiates at approximately 7.60 nm. A third light source of boron ions radiates at approximately 4.86 nm, and a fourth light source of carbon ions radiates at approximately 3.38 nm. Preferred embodiments of apparatus for generating pulsed and continuous discharge sources are disclosed

Adjustable Bore Capillary Discharge

An emitting capillary discharge light source is modified by means to provide for constant, capillary discharge chamber diameter despite interior surface erosion during operation of the light source in order to maintain capillary bore size. The emissions are generated within the capillary discharge chamber and discharged from its outlet. The emission also carries debris generated from within the capillary discharge chamber by erosion of its inner walls reducing its initial inner diameter. The debris is deleterious to the mirrors and other components positioned in the emission stream whereas the erosion distorts the plasma beam. This increase in the initial inner diameter of the discharge chamber leads rapidly to poor imaging of the light stream. By keeping the inner bore diameter of the capillary discharge chamber constant, i.e., 110%, and preferably 105%, of the initial inner bore diameter, the imaging problem is overcome

Discharge Lamp Sources Apparatus and Methods

Capillary discharge extreme ultraviolet lamp sources for EUV microlithography and other applications. The invention covers operating conditions for a pulsed capillary discharge lamp for EUVL and other applications such as resist exposure tools, microscopy, interferometry, metrology, biology and pathology. Techniques and processes are described to mitigate against capillary bore erosion, pressure pulse generation, and debris formation in capillary discharge-powered lamps operating in the EUV. Additional materials are described for constructing capillary discharge devices fore EUVL and related applications. Further, lamp designs and configurations are described for lamps using gasses and metal vapors as the radiating species

Capillary Discharge Extreme UV Lamp Sources for EUV Micrography and other related Applications

Capillary discharge extreme ultraviolet lamp sources for EUV microlithography and other applications. The invention covers operating conditions for a pulsed capillary discharge lamp for EUVL and other applications such as resist exposure tools, microscopy, interferometry, metrology, biology and pathology. Techniques and processes are described to mitigate against capillary bore erosion, pressure pulse generation, and debris formation in capillary discharge-powered lamps operating in the EUV. Additional materials are described for constructing capillary discharge devices fore EUVL and related applications. Further, lamp designs and configurations are described for lamps using gasses and metal vapors as the radiating species

Population Inversions In Lightning Discharges?

Population inversions are typically produced by applying an electrical current through the gas, such as in neon signs. Many possible excitation techniques can provide the pumping energy when this current is applied. These include processes such as electron impact excitation, charge exchange, Penning ionization, atom or molecular collisions, Auger decay, recombination and photoionization pumping. There are a number of molecules, such as excimers and CO2, that produce laser output at much higher pressures, but they are also generally very sensitive to the presence of impurities. Laboratory results have demonstrated a number of recombination lasers in a variety of elements, and researchers have succeeded in producing the nitrogen laser in air. This suggests that these inversions, and possibly even significant stimulated emission, could be occurring in lightning discharges

Intense short wavelength sources for EUV lithography and other applications

Extreme ultraviolet lithography (EUVL) uses reduction imaging to print microchip features smaller than 0.1 μm. The use of all-reflective optics makes it possible to operate a lithographic stepper in the 13-14 nm wavelength range with the necessary throughput required by commercial microchip manufacturers. The Lyman alpha transition in doubly ionized lithium is an efficient source at 13.5 nm. The ratio of excitation energy to radiated energy for this transition is 53% and only two electrons per atom are needed to be removed to produce this radiating state. The optimum lithium plasma radiating at 13.5 nm is estimated to require an electron density of 1018-1019 cm-3 and an electron temperature of 15-20 eV

Laser Fundamental

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The Amazing Cadmium Atom

In this paper, I summarize the unique properties of the Cd atom that have lead to many new types of laser excitation schemes and processes that began 35 years ago. These include the CW blue and ultraviolet laser transitions in Cd+, the generation of 125-ps pulses (the shortest mode-locked pulses at that time), the process of Penning ionization as a laser excitation mechanism, recombination lasers produced by both laser-produced plasmas and a new segmented arc recombination laser (SPER laser) and the first soft-X-ray pumped photoionization laser, which are all described briefly herein

Intense Euv Incoherent Plasma Sources For Euv Lithography And Other Applications

Intense visible and ultraviolet sources, both incoherent and coherent, have been used in a variety of commercial applications over the years. Perhaps two of the most far-reaching applications are in the areas of microlithography and materials processing. In microlithography, the mercury vapor discharge lamp has provided the illuminating flux for microlithography machines for over 20 years. More recently, excimer lasers are playing an increasing role in this field. In materials processing, because of flux requirements that will be discussed later, sources have been largely restricted to lasers. The available lasers cover a wide range of wavelengths and pulse durations and have become major industrial tools for a broad spectrum of applications. This paper will point out the role that intense extreme ultraviolet incoherent (nonlaser) sources might play in the future, in that they may be able to provide similar intensities to those presently provided only by lasers, but in a much simpler, more efficient way and, in some systems, at a potentially much lower cost