Impact of Spatial Coherence
The degree of coherence of the illumination source is determined by the ratio of its angular extent to the numerical aperture. This ratio is often called the partial coherence factor, or . It also affects the pattern quality and hence the application of OPC. The coherence distance in the image plane is given roughly by Two image points separated by more than this distance will effectively be uncorrelated, allowing a simpler OPC application. This distance is in fact close to the Rayleigh criterion for values of close to 1.
Read more about this topic: Optical Proximity Correction
Famous quotes containing the words impact of, impact and/or coherence:
“The question confronting the Church today is not any longer whether the man in the street can grasp a religious message, but how to employ the communications media so as to let him have the full impact of the Gospel message.”
—Pope John Paul II (b. 1920)
“As in political revolutions, so in paradigm choice—there is no standard higher than the assent of the relevant community. To discover how scientific revolutions are effected, we shall therefore have to examine not only the impact of nature and of logic, but also the techniques of persuasive argumentation effective within the quite special groups that constitute the community of scientists.”
—Thomas S. Kuhn (b. 1922)
“Art and ideology often interact on each other; but the plain fact is that both spring from a common source. Both draw on human experience to explain mankind to itself; both attempt, in very different ways, to assemble coherence from seemingly unrelated phenomena; both stand guard for us against chaos.”
—Kenneth Tynan (1927–1980)