Asymmetric fluid-structure dynamics in nanoscale imprint lithography

More documents

Recommendations

Info

minimum gap size at which the reference should be taken still needsquantification. It is believed that by taking a reference in this way, the effect ofK () t can be eliminated.In addition to collecting a reference signal, a dark signal can also becollected to account for the effect of ambient illumination. This dark signal istaken with the tungsten-halogen lamp momentarily off. The dark signal can thenbe subtracted from both the reference signal and intensity signal before theintensity is normalized by the reference as in equation 6.2. The PSD of thenormalized intensity is then taken.~ intenstiy − darkR =reference − dark[6.2]60605050magnitude of the FFT403020magnitude of the FFT403020101000 200 400 600 800 1000 1200 1400 1600 1800 2000FFT index(a)00 200 400 600 800 1000 1200 1400 1600 1800 2000FFT index(b)Figure 6.14 FFT of the intensity of the reflectivity data (a) 2 13 -point FFT(b) 2 14 -point FFTFigure 6.14 shows the effect of the reference signal in the FFT of thereflectivity data. A low frequency false peak appears which has relatively largemagnitude. This poses a problem because the false peak masks the true peak97
when measuring thin layers in the range of about 300 to 400 nm. Figure 6.15illustrates the case when a false peak masks the true peak. The differencebetween 6.14a and 6.14b is that the number of zeros used to pad the FFT has beenincreased by a power of two. This stretches the FFT out and the spectral leakageis increased, however, note that the index at the maximum of the FFT has nowbeen approximately doubled. Spectral leakage is the smearing of energy acrossthe FFT domain, which results in wider peaks. This doubles the resolution since apeak at an FFT index of 200.5, which cannot be resolved in 6.14a, is now equal toa peak at an FFT index of 401 in 6.14b, for example.y g18magnitude of the FFT1614121086False peakTrue peak4200 1000 2000 3000 4000 5000 6000 7000 8000 9000FFT indexFigure 6.15 False signal masking the true signal in FFT6.5.3 Template/Substrate DeformationThe template and substrate can be deformed when using setscrews toconstrain their positions. The setscrews cause local stress concentrations that areundesirable. This leads to possible bowing of the template and substrate. Tominimize the effect of stress concentrations on the bowing of the template andsubstrate, flat aluminum plates were placed between the setscrews and the quartzpieces.98
Page 3 and 4:
Asymmetric Fluid-StructureDynamics
Page 5 and 6:
AcknowledgementsFirst of all, I wou
Page 7 and 8:
Table of ContentsList of Tables ...
Page 9 and 10:
6.2.3 Control Software ............
Page 11 and 12:
List of FiguresFigure 1.1 Optical m
Page 13 and 14:
Figure 6.9 Force due to fluid press
Page 15 and 16:
The exponential escalation in the c
Page 17 and 18:
1.2.1 Optical Lithography Process O
Page 19 and 20:
patterns to the desired specificati
Page 21 and 22:
1.3 STEP AND FLASH IMPRINT LITHOGRA
Page 23 and 24:
transferlayerwaferStep 1: Spin-coat
Page 25 and 26:
the etch barrier fluid has an infin
Page 27 and 28:
Researchers at the University of Te
Page 29 and 30:
stage development. Design requireme
Page 31 and 32:
minimum and maximum base layer thic
Page 33 and 34:
square plate with fluid completely
Page 35 and 36:
7. The fluid is assumed incompressi
Page 37 and 38:
⎛ ∂ ⎞⎜τdz ⎟dxdy⎝+ τ
Page 39 and 40:
where V 1 and V 2 correspond to U 1
Page 41 and 42:
ddx⎛⎜h⎝3dp ⎞ ∂h⎟ = 12µ
Page 43 and 44:
dhdtLzhθh αh βxx αx = 0 x βFig
Page 45 and 46:
C2hhtanθ2 21= αxαxβxαxβ( ) (
Page 47 and 48:
⎛⎜ hD⎜⎝6C ⎞1tanθ⎟24µh
Page 49 and 50:
at the plate edges. Freeland obtain
Page 51 and 52:
For the case of 10 psi of pressure,
Page 53 and 54:
are the same as the width of the tr
Page 55 and 56:
orientation stages relative to the
Page 57 and 58:
Wafer ChuckAir SolenoidMounting Pla
Page 59 and 60: The one degree-of-freedom template
Page 61 and 62: Figure 3.7 Initial and final desire
Page 63 and 64: 7645321Figure 3.8 Active stage prot
Page 65 and 66: Chapter 4: Real-Time Gap Sensing Vi
Page 67 and 68: R( λ)( 4πnd/ λ)2 2 −2αd−αd
Page 69 and 70: Rate Monitoring and is adapted for
Page 71 and 72: 10090807060PSD504030201000 500 1000
Page 73 and 74: the multi-imprint and active stage
Page 75 and 76: 5.2.2 Composite Stiffness and Dampi
Page 77 and 78: ( )2πR−1.5clamping length of 1.5
Page 79 and 80: 65actuator height, micron432100 0.1
Page 81 and 82: time marching is required to minimi
Page 83 and 84: 5.4 SQUEEZE FILM DYNAMICS OF INCLIN
Page 85 and 86: force, lb504540353025201510500 0.05
Page 87 and 88: improve upon these results by tunin
Page 89 and 90: Again, Figure 5.12 shows that a bas
Page 91 and 92: optically flat quartz plate coated
Page 93 and 94: optic probe was illuminated with a
Page 95 and 96: Figure 6.3 Screenshot of control so
Page 97 and 98: 6.3 EXPERIMENTAL PROCEDUREExperimen
Page 99 and 100: film thickness, nm40003800360034003
Page 101 and 102: Figure 6.6 shows that the force due
Page 103 and 104: similar. In Figures 6.7 and 6.8, th
Page 105 and 106: 500045004000film thickness, nm35003
Page 107 and 108: Figure 6.13 shows the force-time pl
Page 109: ⎛ n ⎞in the FFT that is not ind
Page 113 and 114: is a major milestone. The next step
Page 115 and 116: 7.2.4 Control schemeThe ultimate go
Page 117 and 118: Assuming the liquid perfectly wets
Page 119 and 120: ase h (for a semi-circular notch,h
Page 121 and 122: Chou, S. Y., P .R. Krauss, and P. J
Page 123 and 124: Tripp, J. H. 1983. Surface roughnes
show all

Asymmetric fluid-structure dynamics in nanoscale imprint lithography

Create successful ePaper yourself

Delete template?

Save as template?