mask metrology and pattern profile analysis using the ait: down to 65 nm · mask metrology and...
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Mask Metrology and Pattern Profile Analysis Using the AIT: Down to 65 nm
I. Mochi, K. A. GoldbergLawrence Berkeley National Laboratory
Tom WallowGlobalFoundries
2010 International Workshop on EUV Lithography
The SEMATECH Berkeley Actinic Inspection Tool
λ = 13.2 – 13.6 nm
NA :0.0875 (0.35 4x)0.0750 (0.30 4x)0.0625 (0.25 4x)
Magnification : 907x
Through focus image series95 nm HP – 0.0875 NA
-2.8 µm -2.4 -2.0 -1.6 -1.2
-0.8 -0.4 0.0 0.4 0.8
1.2 1.6 2.0 2.4 2.8
1.2
µm
(24 nm HP – 0.35 NA)
The AIT currently resolves dense line patterns > 65 nm
100 nm(25 nm)
GlobalFoundriesMask MET10
300 nm
I 1
0.5
0
The AIT currently resolves dense line patterns > 65 nm
95 nm(24 nm)
GlobalFoundriesMask MET10
300 nm
I 1
0.5
0
The AIT currently resolves dense line patterns > 65 nm
90 nm (23 nm)
GlobalFoundriesMask MET10
300 nm
I 1
0.5
0
The AIT currently resolves dense line patterns > 65 nm
85 nm(21 nm)
GlobalFoundriesMask MET10
300 nm
I 1
0.5
0
The AIT currently resolves dense line patterns > 65 nm
80 nm(20 nm)
GlobalFoundriesMask MET10
300 nm
I 1
0.5
0
The AIT currently resolves dense line patterns > 65 nm
75 nm(19 nm)
GlobalFoundriesMask MET10
300 nm
I 1
0.5
0
The AIT currently resolves dense line patterns > 65 nm
70 nm(18 nm)
GlobalFoundriesMask MET10
300 nm
I 1
0.5
0
The AIT currently resolves dense line patterns > 65 nm
65 nm(16 nm)
GlobalFoundriesMask MET10
300 nm
I 1
0.5
0
Photon flux requirements for EUV reticle imaging microscopy in the 22- and 16nm nodesDaniel T. Wintz, Kenneth A. Goldberg, Iacopo Mochi, and Sungmin Huh, Proc. SPIE 7636, 76362L (2010)
How many photons do we need?
1µm
1µm 1µm
1µm 1µm
EUV Defect imaging with the AIT
Actinic imaging of native and programmed defectson a full-field maskI. Mochi, K. A. Goldberg, B. La Fontaine, A. Tchikoulaeva, C. Holfeldt,
Proc. SPIE 7636 76371A, (2010)
AIT: Tunable λ measurements from 13.2–13.6 nm
λ/Δλ=1/1450
AITbandwidth
• Narrow-band illumination is required for zoneplates.• The AIT can operate across a range of wavelengths
to synthesize broad-spectrum EUV illumination. Huh, SEMATECH
Native phase defects show little λ dependence
1.5
0.0
I
Def
ect V
Def
ect X
Def
ect 1
Def
ect 2
λ = 13.2 13.3 13.4 13.5 13.6 nm
Huh, SEMATECH
Phase Retrieval from Defocused Images and Its Applications in LithographyRudolf M. von Bunau, Hiroshi Fukuda and Tsuneo TerasawaJpn. J. Appl. Phys. 36 (1997) 7494
A practical algorithm for the determination of the phase from image and diffraction plane picturesR. W. Gerchberg and W. O. SaxtonOptik 35, 237 (1972)
?Initial phase guess
Measured amplitudes(known)
Reconstructed phase
LensMask
G-S modified algorithm
P
π/2
-π/2
0
0.39
-0.36
Phase roughness on a blank mask
π/2
-π/2
0±π
Reconstructed phase
0.5 µm
In focus image
Single surface approximation height
0.8 nm (pv)0.14 nm (rms)
Conclusion
This work was supported by SEMATECH, through the U.S. Department of Energy under Contract No. DE-AC02-05CH11231
Phase roughness
BossungNILSContrast
λsensitivity
Phase defects
LER Defect inspection
OPC Correction