ISSN:
1662-0356
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Natural Sciences in General
,
Technology
Notes:
Lithographic processes belong to the most critical steps in the fabrication of microelectroniccircuits. Optical projection lithography which transfers the layout of a mask into a photoresistat the top surface of a silicon wafer is still the workhorse of semiconductor industry. Many innovationsregarding the optical imaging system and the introduction of new mask technologies havepushed optical projection techniques close to their theoretical limits. Nowadays, optical projectionlithography is used to create 45nm features with a wavelength of 193nm.This paper discusses the impact of the mask on the performance of a lithographic process. For largefeature sizes the mask can be considered as infinitely thin and its local transmission and phase canbe directly derived from the design. For mask features comparable to the wavelength of the usedlight and below, the mask becomes a complex scattering object which has a pronounced impact onthe intensity, phase, and polarization of the diffracted light. The light diffraction from the mask hasto be computed by rigorous electromagnetic methods. Several consequences with respect to thechoice of most appropriate mask materials and geometries will be discussed
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/42/transtech_doi~10.4028%252Fwww.scientific.net%252FAST.55.173.pdf
