US 7,321,467 B2
Anti-reflection coating layer and design method thereof
Chun-Chung Huang, Hsinchu (Taiwan)
Assigned to MACRONIX International Co., Ltd., Hsinchu (Taiwan)
Filed on May 26, 2005, as Appl. No. 10/908,783.
Prior Publication US 2006/0268415 A1, Nov. 30, 2006
Int. Cl. G02B 1/10 (2006.01)
U.S. Cl. 359—586  [359/589] 17 Claims
OG exemplary drawing
 
1. An anti-reflection coating layer suitable to be formed between an under layer and a photoresist layer, the anti-reflection coating layer characterized in:
a refraction (n) of the anti-reflection coating layer, wherein n is a constant; and
an extinction coefficient (k) of the anti-reflection coating layer, wherein k is increased in gradient toward the under layer, wherein the k of the anti-reflection coating layer is increased in gradient from a top set as 0 to the under layer.