(12) Ullltfild States Patent (10) Patent No.: US 7,426,712 B2
Kotani et al. (45) Date of Patent: Sep. 16, 2008
LITHOGRAPHY SIMULATION METHOD AND RECORDING MEDIUM
Inventors: Toshiya Kotani, Tokyo (JP); Shigeki Nojima, Yokohama (JP); Shoji Mimotogi, Yokohama (JP)
Assignee: Kabushiki Kaisha Toshiba, Tokyo (JP)
Notice: Subject to any disclaimer, the term of this
patent is extended or adjusted under 35
U.S.C. 154(b) by 245 days.
Appl. No.: 11/485,554
Filed: Jul. 13, 2006
US 2007/0019058 A1 Jan. 25, 2007
Foreign Application Priority Data
13, 2005 (JP) ........................... .. 2005-204146
Int. Cl.
G06F 17/50 (2006.01)
G03F 9/00 (2006.01)
U.S. Cl. ........................................... .. 716/19; 430/5
Field of Classification Search ................. .. 716/ 19; 430/5
See application file for complete search history. References Cited
5,563,012 A * 10/1996 Neisser ...................... .. 430/22
5,889,686 A 3/1999 Mimotogi et al. 6,617,083 B2 9/2003 Usui et al. 7,363,611 B2* 4/2008 Rosenbluth ................ .. 716/21
Primary Examiner—Jack Chiang
Assistant Examiner—Magid Y Dimyan
(74) Attorney, Agent, or Firm—Finnegan, Henderson, Farabow, Garrett & Dunner, L.L.P.
A lithography simulation method includes: taking in design data of a pattern to be formed on a substrate and mask data to prepare a mask pattern used in forming a latent image of the pattern on the substrate by transmission of an energy ray; obtaining the latent image of the pattern by calculation of an intensity of the energy ray; locally changing, at least in a portion corresponding to a pattern of interest, a relative position in a direction of the intensity of the energy ray between a latent image curve and a reference intensity line in accordance with a distance between the pattern of interest and a pattern of a neighboring region , the latent image curve being an intensity distribution curve of the energy ray constituting the latent image, the reference intensity line being defined to specify a position of an edge of the pattern of interest; and calculating a distance between intersections of a portion of the latent image curve corresponding to the pattern of interest and the reference intensity line in the changed relative position to define a line width of interest of the pattern of interest.
8 Claims, 6 Drawing Sheets
CALCULATE LATENT IMAGE I"’$2
WT CALCQULATE MODULATED $3
L [LATENT IMAGE]
SELECT PATTERN 0 $4
I OF INTEREST
CALCULATE WIDTH W OF PATTERN S5
OF INTEREST OR SPACE WIDTH S
BETWEEN PATTERN OF INTEREST
I AND PATTERN ADJACENT THERETO
DETERMINE SHIFT AMOUNT IN 56
ACCORDANCE WITH WIDTH w on SPACE
WIDTH s on e§s__31s2c>1= Ruuz TABLE
MOVE MODULATED LATENT IMAGE OR $7
REFERENCE INTENSITY LINE AS MUCH
AS DETERMINED SHIFT AMOUNT IN
OPTICAL INTENSITY DIRECTION
CALCULATE DISTANCE BETWEEN INTERSECTlONS $3 OF REFERENCE INTENSITY LINE AND MODULATED
LATENT IMAGE AFTER MOVED, AND OUTPUT CALCULATED DISTANCE AS LINE WIDTH OF INTEREST
