Lambda Physik Ag

Coherent, Inc.

Elko Bergmann

Klaus Wolfgang Vogler

Frank Voss

Sergei V Govorkov

Gongxue Hua

Thomas Schroeder

Frank Simon

Holger Graefe

Uwe Wiedenbruch

The present invention provides laser beam micro-smoothing for laser annealing systems. Laser beam micro-smoothing comprises shifting a laser beam in the direction perpendicular to the scanning direction (y) of a laser annealing system, while holding the laser beam fixed in the direction of scanning (x). The shifting may be accomplished, for example, with a pair of micro-smoothing mirrors. The shifting smoothes out small-scale inhomogeneities in the profile of the laser beam and prevents microscopic stripes associated with prior art laser annealing systems. Because the shifting occurs only in the direction perpendicular to the scanning direction (y), the laser annealing process in not adversely affected.

Laser beam micro-smoothing

A beam parameter monitoring unit for coupling with a molecular fluorine (F) or ArF laser resonator that produces an output beam having a wavelength below 200 nm includes a detector and a beam path enclosure. The unit may also include a beam splitter within the enclosure for separating the output beam into first and second components, or first and second beam are attained by other means. The detector measures at least one optical parameter of the second component of the output beam. The beam path enclosure includes one or more ports for purging the beam path enclosure with an inert gas to maintain the enclosure substantially free of sub-200 nm photoabsorbing species. An optical path of the second component of the output beam through the enclosure from the laser resonator to the detector is substantially free of ssub-200 nm photoabsorbing species so that the second beam component reaches the detector without substantial attenuation from the photoabsorbing species, while the first component is used for processing a workpiece.

Energy monitor for molecular fluorine laser

A F laser includes a laser tube filled with a laser gas mixture at least including molecular fluorine for generating a spectral emission including multiple closely-spaced lines in a wavelength range between 157 nm and 158 nm, including a first line centered around 157.62 nm and a second line centered around 157.52 nm, multiple electrodes within the discharge chamber connected with a power supply circuit for energizing the molecular fluorine, a laser resonator including a line selection unit for selecting one of the first and second lines of the multiple closely spaced lines and for supressing the other of the first and second lines, for generating a narrow bandwidth VUV output beam, and at least one intracavity polarizing element. The narrow bandwidth VUV output beam is polarized at least 95%, and may be 98% or more.

Molecular fluorine laser with intracavity polarization enhancer

A molecular fluorine laser includes a discharge chamber filled with a gas mixture including molecular fluorine and a buffer gas and not including a laser active rare gas, multiple electrodes within the discharge chamber defining a discharge region therebetween connected to a pulsed discharge circuit for applying discharge pulses to the electrodes for energizing the gas mixture, and a resonator including the discharge chamber for generating an oscillator laser beam at a wavelength around 157 nm and a bandwidth of less than 0.6 pm. The laser further includes a power amplifier for increasing the energy of the attenuated oscillator laser beam to a second predetermined energy for lithographic processing, a line-narrowing unit for reducing the bandwidth, a low intensity suppressor module to suppress the weaker lines of the F -laser, and a synchronization unit to synchronize the oscillator and amplifier.

Growing community of inventors

Goettingen, Germany

Elko Bergmann