TY - GEN

T1 - Excimer mirror thin film laser damage competition

AU - Stolz, Christopher J.

AU - Blaschke, Holger

AU - Jensen, Lars

AU - Mädebach, Heinrich

AU - Ristau, Detlev

PY - 2011/12/6

Y1 - 2011/12/6

N2 - Excimer lasers are a critical technology for the $400 billion annual market of manufactured integrated circuits. Other uses of excimer lasers include medical applications such as laser eye surgery and micro-machining industrial applications. Ultraviolet laser mirrors are used for beam steering, therefore high reliability is desired for such commercial industrial applications. A laser damage competition of excimer mirror coatings creates the opportunity to survey private industry, governmental institutions, and university labs allowing a direct laser resistance comparison of samples tested under identical conditions. The major requirement of the submitted coatings was a minimum reflectance of 97% at 193 nm at normal incidence. The choice of coating materials, design, and deposition method were left to the participant. Damage testing was performed with a 193 nm excimer laser at a pulse length of 13 ns. A double blind test assured sample and submitter anonymity so only a summary of the deposition process, coating materials, layer count and spectral results are presented. In summary, a 70× difference was seen in the twelve submitted mirror samples, with the highest laser resistant sample being deposited by resistive heating and composed of three materials (LaF3, AlF3, & MgF2). Laser resistance was strongly affected by substrate cleaning, coating deposition method, and coating material selection whereas layer count had a minimal impact.

AB - Excimer lasers are a critical technology for the $400 billion annual market of manufactured integrated circuits. Other uses of excimer lasers include medical applications such as laser eye surgery and micro-machining industrial applications. Ultraviolet laser mirrors are used for beam steering, therefore high reliability is desired for such commercial industrial applications. A laser damage competition of excimer mirror coatings creates the opportunity to survey private industry, governmental institutions, and university labs allowing a direct laser resistance comparison of samples tested under identical conditions. The major requirement of the submitted coatings was a minimum reflectance of 97% at 193 nm at normal incidence. The choice of coating materials, design, and deposition method were left to the participant. Damage testing was performed with a 193 nm excimer laser at a pulse length of 13 ns. A double blind test assured sample and submitter anonymity so only a summary of the deposition process, coating materials, layer count and spectral results are presented. In summary, a 70× difference was seen in the twelve submitted mirror samples, with the highest laser resistant sample being deposited by resistive heating and composed of three materials (LaF3, AlF3, & MgF2). Laser resistance was strongly affected by substrate cleaning, coating deposition method, and coating material selection whereas layer count had a minimal impact.

KW - damage testing

KW - excimer laser

KW - ISO21254-2

KW - mirror

KW - multilayer

KW - nanosecond pulse length

KW - thin film

UR - http://www.scopus.com/inward/record.url?scp=84856351542&partnerID=8YFLogxK

U2 - 10.1117/12.899187

DO - 10.1117/12.899187

M3 - Conference contribution

AN - SCOPUS:84856351542

SN - 9780819488237

T3 - Proceedings of SPIE - The International Society for Optical Engineering

BT - 43rd Annual Laser Damage Symposium Proceedings - Laser-Induced Damage in Optical Materials

T2 - 43rd Annual Laser Damage Symposium - Laser-Induced Damage in Optical Materials: 2011

Y2 - 18 September 2010 through 21 September 2010

ER -