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Department Library

2011

Matthew Nilsen (Capstone, August 2011, Advisor: Larry Knight )

Abstract

This report informs the reader of the field of extreme ultraviolet (EUV) lithography, offering necessary background information and describing the development of a wide range spectrometer that has been designed to meet the requirements of this field. EUV lithography is a process for etching nano-sized features on a computer chip using high-energy, short wavelength radiation. Creating a spectrometer for the EUV range is very difficult due to attenuation, and violent deposition of materials on sensitive optics. Our wide range spectrometer (WRS) was developed using a laser produce plasma (LPP) and a series of mirrors with a transmission grating. This design gives it a compact size, resistance to deposition and ability to resolve a very wide spectral range, all necessary in EUV lithography.

2010

Jershon Lopez (Senior Thesis, August 2010, Advisor: Larry Knight )

Abstract

We have developed a compact (6 x 20 cm), wide-range (2 - 200 nm) spectrometer for diagnosing laser-produced plasma. The characterization of one of its interchangeable transmission gratings (2000 lines/mm) is described in this report. The grating has zeroth and first order diffraction efficiencies of 9.2% and 9.9% respectively. Plasma spectra obtained with this grating are also included.

2009

Bryce Allred (Senior Thesis, April 2009, Advisor: Larry Knight )

Abstract

We developed and are calibrating an Extreme Ultraviolet (EUV) transmission grating spectrometer for absolute intensity measurements over an extremely wide spectral range. Spectra from ablated Li, Fe, Sn, and W solid targets have been recorded and analyzed. We have acquired spectral resolution of 0.2 nm from wavelengths of 2 to 85 nm, with an overall spectral range of 2 to 250 nm. The device is very compact (60 x 200 mm) and ideal for absolute intensity measurements at 13.5 nm as well as for characterizing EUV lithography plasma sources. The CCD camera detector can be absolutely calibrated to equate the intensity recorded to electron energy and plasma temperature.

Jeffrey Kemp (Senior Thesis, April 2009, Advisor: Larry Knight )

Abstract

I participated in the development of a broadband spectrometer for the diag- nosis of high energy plasmas (2-250 nm). Spectra for Li, Fe, Sn, W, Mo, and Al have been obtained for these high energy transitions using a Toshiba TCD1304AP linear array CCD and an ORMINS analog to digital Converter. A new method for obtaining spectra has been implemented to facilitate the development of a computer interface that allows for real time analysis of high energy plasmas. This method replaces the analog to digital converter with a LeCroy Wavejet 354 oscilloscope. Spectra have been obtained using the LeCroy ScopeExplorer program. It is now possible to develop a computer in- terface in LabVIEW that will allow for the real time analysis of spectra in the 2-250 nm range.

2008

Nathan Gray (Senior Thesis, April 2008, Advisor: Larry Knight )

Abstract

We constructed and tested a spectrometer which can be used in applications such as plasma diagnostics for extreme ultraviolet lithography. Its design is simple and compact. Efficiency has been calculated. It provides real-time calibrated spectral information. We present a variety of plasma spectra that have been recorded with it.

2007

Matthew Harrison (Capstone, April 2007, Advisor: Larry Knight, Alexander Shevelko )

Abstract

Several conical spectrometers were built and used to monitor x-ray emission from laser produced plasmas. The plasmas were created using an Nd-YAG laser (.53 um/200 mJ/3 ns/1 Hz) on solid metal targets, principally magnesium and iron. Two detectors were used to record spectrum, a linear charge-coupled device (CCD) and EUV sensitive photographic film. Spectrum were recorded at a variety of distances from the target, from 3 cm to 90 cm. Observed wavelengths fall within the spectral range of 9-15 Å. A unique mounting structure and conical design were used in order to obtain spectra at a distance of 20 cm or more. Spectra acquired at close range have been calibrated for wavelength. When using a CCD as a detector, the spectrometers are capable of providing shot-to-shot spectral information of the laser produced plasmas. Such a diagnostic capability is promising for automated processes that plan to use laser produced plasmas as an x-ray source, such as x-ray lithography.

Nathan Packard (Capstone, April 2007, Advisor: Larry Knight, Matt Asplund )

Abstract

A laser produced plasma provides a high powered pulse in the x-ray regime. This compact, low cost and reliable x-ray source has been harnessed and controlled to aid the lithography process. A conical spectrometer derived from Von Hamos’ cylindrical spectrometer provides multiple advantages over the cylinder. While similar to the cylinder, using mica crystal for a diffraction grating, the cone provides for greater flexibility. More room in the working space, greater protection of the grating, and increased flexibility in obtainable spectral range are significant advantages over the cylinder. All spectra previously obtained by the cylinder have been duplicated in the cone, as well as many others. Our ability to match Von Hamos’ spectrum provides great reliability and validity to our approach.

2004

Jon Johnson (Senior Thesis, August 2004, Advisor: Larry Knight )

Abstract

n/a

2002

Jared Estus Daily (Senior Thesis, April 2002, Advisor: Larry Knight )

Abstract

Joshua A. Strong (Senior Thesis, December 2002, Advisor: Larry Knight )

Abstract

1998

Jason W. Mumford (Senior Thesis, April 1998, Advisor: Larry Knight )

Abstract

1996

David Christiansen (Senior Thesis, May 1996, Advisor: Larry Knight )

Abstract

B. Scott Williams (Senior Thesis, August 1996, Advisor: Larry Knight )

Abstract

1995

Mitch Larsen (Senior Thesis, February 1995, Advisor: Larry Knight )

Abstract

1992

Evan D. Hansen (Honors Thesis, April 1992, Advisor: Larry Knight )

Abstract

Nathan Rhead Hilton (Honors Thesis, May 1992, Advisor: Larry Knight )

Abstract