Browsing by Author "Loong, WA"

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AlSixNy as an embedded layer for attenuated phase-shifting mask in 193 nm and the utilization of a chemically amplified negative resist NEB-22 for maskmaking
(2000-06-01)
Loong, WA
;
Lin, CM
;
應用化學系
;
Department of Applied Chemistry
AlSixNy (x similar to 0.31, y similar to 0.45) thin film as a new embedded material for AttPSM in 193 nm lithography was presented. With the good controlling of plasma sputtering of Al (100 similar to 130 W) and Si (20 similar to 50 W) under Ar (75 seem), and nitrogen (2.5 similar to 5 seem), AlSixNy has enough deposition latitude to meet the requirements as an embedded layer. For required phase shift 180 degree, the calculated thickness d(180) of AlSixNy films is in the range of 87 similar to 100 nm. The T% in 365 and 488 nm for optical inspection and alignment is below 40%. Its sheet resistance R-s, is less than 0.8 k Omega/square. Helicon wave plasma etcher and Taguchi design of experiment have been applied to the study of the etching selectivity of AlSixNy over substrate fused silica and negative resist NEB-22. Under chamber pressure 3 mtorr, BCl3 45 sccm, Cl-2 7 seem, plasma source power 1400 W and substrate bias RF power 30 W for the selectivity of AlSixNy over NEB-22 was found to be 4.8:1. The selectivity of AlSixNy over fused silica was 12.3:1 under chamber pressure 9 mtorr, BCl3 13 seem, Cl-2 45 seem, O-2 8 seem, plasma source power 1400 W and substrate bias RF power 30 W. A 0.3 mu m line/space etched pattern using AlSixNy as embedded layer was successfully fabricated.
AlSixOy as a high-transmittance embedded material of ternary attenuated phase-shifting mask and correlation between chemical composition and optical properties of AlSixOy in 193 nm lithography
(2000-12-01)
Lin, CM
;
Loong, WA
;
應用化學系
;
Department of Applied Chemistry
AlSixOy (Al : Si : O = 1 : 0.36 : 0.88) thin film has the potential for use as a new and high-transmittance (T% similar to 35%) embedded layer of an attenuated phase-shifting mask (AttPSM) in 193 nm lithography. Increasing the compositions of Al2O3, SiO2 and other oxides increases n and decreases k in AlSixOy. Compared to a conventional AttPSM (T% < 10%), the high-T% AttPSM assisted by opaque Cr scattering bars can achieve a greater depth of focus, 0.45 m for a 0.10 mum isolated line. Under the conditions of BCl3/Cl-2 = 30/7 seem, chamber pressure 3 mTorr; source power 1400 W and RF bias power 30 W, the etching selectivity of AlSixOy over positive resist EP-1EG is 7.7 : 1. Under those of BCl3/Cl-2/O-2 = 35/7/3.2 seem, the selectivity of AlSixOy over substrate fused silica is 5.8 : 1. A 0.25-mum-line/space (1 : 1) etched pattern was successfully fabricated using AlSixOy as an embedded layer.
Chemical stability of embedded material for attenuated phase-shifting mask and application of high-transmittance attenuated phase-shifting mask for 0.1 mu m contact pattern in 193 nm lithography
(2002-06-01)
Lin, CM
;
Loong, WA
;
應用化學系
;
Department of Applied Chemistry
When the compositions of Al2O3. SiO2., and other oxides were increased, refractive index (n) appeared to increase and extinction coefficient (k) to decrease in AlSixOy. The study of the correlation among sputtering conditions, chemical compositions and optical properties could lead to the chemical stability of AlSixOy embedded material. Bi layer AlSixOy thin film may be a new high-transmittance (T% similar to 35%) embedded layer of attenuated phase-shifting masks (AttPSMs) in 193 nm lithography, The transparent layer with saturation of Al2O3 and SiO2 compositions exhibits n of 2.3-2.4 and k of 0.1-0.2. The absorptive layer with higher concentrations of Al and Si exhibits n of 1.5-1.7 and k of 0.3-0.4. Combining a dark-tone mask, high-transmittance AttPSM and negative resist resulted in better contrast of the aerial image and a resolution of 0.1 mum for the contact-hole pattern in 193 nm lithography, A 0.20-mum-line/space (1: 1) etched pattern was successfully fabricated using AlSixOy, as an embedded layer.
Correlation between the chemical compositions and optical properties of AlSixNy embedded layer for attenuated phase-shifting mask in 193 nm and the modification of the R-T method for measuring n and k
(2000-11-01)
Lin, CM
;
Loong, WA
;
應用化學系
;
Department of Applied Chemistry
The formation and variation of AlN, Si3N4, and nitride compositions in AlSixNy (x similar to0.31, y similar to0.51) embedded material have been shown to correlate with its optical properties. The increasing content of AIN, Si3N4, and nitrides will increase n and decrease k of AlSixNy. A simple and effective correction of measured reflectance R% and transmittance T% based on scalar scattering theory has been applied to the R-T method for determining It and k of embedded layers for 193 nm lithography masks. A 0.2 mum etched pattern of an AlSixNy embedded layer on an oxide/Si wafer substrate was successfully fabricated. (C) 2000 American Vacuum Society. [S0734-211X(oo)08906-X].
Modified reflectance-transmittance method for the metrology of thin film optical properties
(2006-03-01)
Yeh, KT
;
Lin, CH
;
Hu, JR
;
Loong, WA
;
應用化學系
Because the surface roughness of a thin film will cause light scattering, the reflectance (R) and transmittance (T) measured using a UV/visible (vis) spectrometer become lower than the actual values. The deviation becomes larger with increasing roughness and decreasing wavelength of incident light. Hence, it is necessary to correct measured R and T using roughness as a modification factor. The refraction (n) and extinction coefficient (k) obtained by the modified R-T method are closer to those results obtained using a variable angle spectroscopic ellipsometer (VASE), which provides more precise results than a n and k analyzer.
Simulations of mask error enhancement factor in 193nm immersion lithography
(2006-04-01)
Yeh, KT
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Loong, WA
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應用化學系
;
Department of Applied Chemistry
In general, better resolution and lower mask error enhancement factor (MEEF) are obtained when a higher numerical aperture (NA) is used. However, simulations in this study show that, if Y-polarized light and off-axis illuminations were used, higher NA leads to higher MEEF for smaller and dense feature line sizes in 193nm immersion lithography. The reversal of the MEEF was clearly observed, especially in the presence of a dipole. When the feature size decreased to the resolution limit, the MEEF rose enormously. Simulations also show that the MEEF is inversely proportional to the cubic root of image contrast in most cases in this study.
Studies of nitride- and oxide-based materials as absorptive shifters for embedded attenuated phase-shifting mask in 193 nm
(1999)
Lin, CM
;
Chang, KW
;
Lee, MD
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Loong, WA
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應用化學系
Five materials which are PdSixOy CrAlxOy, SiNx, TiSixNy and TiSixOyNz as absorptive shifters for attenuated phase-shifting mask in 193 nm wavelength lithography are presented. PdSixOy films were deposited by dual e-gun evaporation. CrAlxOy, TiSixNy and TiSixOyNz films were formed by plasma sputtering and SiNx films were formed with LPCVD. All of these materials are shown to be capable of achieving 4%similar to 15% transmittance in 193 nm with thickness that produce a 180 degrees phase shift. Under BCl3:Cl-2=14:70 seem; chamber pressure 4 mtorr and RF power 1900W, the dry etching selectivity of TiSixNy over DQN positive resist and fused silica, were found to be 2:1 and 4.8:1, respectively. An embedded layer TiSixNy with 0.5 mu m line/space was successfully patterned.
Study on optimization of annular off-axis illumination using Taguchi method for 0.35 mu m dense line/space
(1997-02-01)
Loong, WA
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Tseng, JC
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Chen, TC
;
Lung, CA
;
交大名義發表
The simulation and experiment study on optimizations of process factors under annular off-axis illumination (AOAI) using Taguchi method for design of experiment (DOE) for 0.35 mu m dense line/space in i-line was reported in this paper. The optimized simulation results for both resolution and DOF are as follows: inner ring sigma(i) = 0.35, outer ring sigma(o) = 0.70, NA = 0.5, negative bias on mask for line in dense line/space similar to 0.03 mu m (L/S = 0.320/0.380 mu m), positive bias on mask for isolated line similar to 0.03 mu m (iso. L = 0.38 mu m), overlapped DOF (dense + isolated) similar to 1.86 mu m, exposure dose similar to 278 mJ/cm(2). The experimental results are in good agreement with simulations. The optimized results by experiments with a NA of 0.57 and with AOAI are as follows: inner ring sigma(i) = 0.35, outer ring sigma(o)= 0.70, negative bias on mask for line in dense line/space similar to 0.015 mu m (L/S=0.335/0.365 mu m), positive bias on mask for isolated line similar to 0.03 mu m (iso. L = 0.38 mu m), overlapped DOF (dense + isolated) similar to 1.7 mu m, exposure time similar to 520 ms (exact dose uncertain). Without AOAI but with the same mask bias, the overlapped DOF is similar to 1.2 mu m by experiment. The overlapped DOF from mask patterns without any bias (L/S = 0.35/0.35 mu m; iso. L = 0.35 mu m) with 1/2 AOAI is similar to 0.93 mu m; and from conventional illumination without mask bias is up to similar to 0.72 mu m at most. The DOF, proximity effect and resolution for dense L/S are obviously improved from 1/2 AOAI exposure after optimization if compared with conventional exposure. The Taguchi method is also proved valuable in this study.
The correlation between the chemical compositions and optical properties of TiSixNy as an embedded layer for AttPSM in 193 nm
(2001-09-01)
Loong, WA
;
Lin, CM
;
Tseng, SP
;
Yeh, WL
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應用化學系
We reported that the optical and physical properties of TiSixNy thin films formed by sputtering are suitable to be used as an embedded layer in 193 nm. The TiSixNy films were deposited under DC power of Ti target 170-220 W, RF power of Si target 50-110 W, Ar 50 sccm and N-2 3-7 sccm. The increasing of the atomic percentage of nitrogen in TiSixNy has a good agreement with its n and k. With the formation of Si3N4 and TiN structures, the TiSixNy thin film's n started to increase, k to decrease. After the saturation of formations of Si3N4 and TiN structures, the Si and Ti states started to show up, resulted this thin film's n to decrease, and k to increase. The n and k values were calculated by our modified R-T (reflectance-transmittance) method. Controlling a thin film's compositions during sputtering could allow the manipulation of its n and k. (C) 2001 Elsevier Science B.V. All rights reserved.
The simulation of application of high transmittance AttPSM for sub-100 nm pattern in 248 nm lithography
(2001-09-01)
Lin, CM
;
Loong, WA
;
應用化學系
;
Department of Applied Chemistry
In contrast to the normal transmittance (T < 10%) attenuated phase-shifting mask (AttPSM), the high transmittance AttPSM assisted with Cr scattering bars could enhance the resolution of aerial image down to about 0.1 mum isolated line in clear-field mask. With transmittance T = 35% of the 0.1-mum isolated line as embedded layer, the optimized width of scattering bars is 0.085 mum, the distance between Cr scattering bar and 0.1 mum isolated line is 0.205 mum, and DOF is 0.53 Rm under the optimized quadrupole illumination with 0.51/0.27 (sigma (offset)/sigma (radius)). Compared to transmittance 5 and 15% of embedded layer, the negative and positive factors of mask error enhancement factor (MEEF) could be kept in the range of - 2 to + 2 for isolated lines wider than 80 mum at transmittance 35%, assisted with the 0.085-mum width of Cr scattering bars. (C) 2001 Published by Elsevier Science B.V.
TiNx as a new embedded material for attenuated phase shift mask
(1996-01-01)
Loong, WA
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Chen, TC
;
Tseng, JC
;
交大名義發表
;
應用化學系
In this paper TiNx (x > 1.3) as a new material suitable for using as an embedded layer for an attenuated phase shift mask (APSM) is presented. TiNx thin film was formed by plasma sputtering under a gas mixture of Ar and N-2 (40:2 sccm). The related characteristics of TiNx at 365 nn (i-line) wavelength are as follows: n (refractive index) similar to 3.07; k (absorbance coefficient) similar to 0.531; R (reflectivity) 27 similar to 30%; rho (resistivity) similar to 52 mu Omega-cm (132 nm on quartz). For required phase shift degree theta=180 degrees, calculated thickness d of TiNx film is 88.2 nn, and transmittance T under 365 nm wavelength at this thickness is 14.5 % which is within the useful range for APSM. TiNx film also has good electrical conductivity, suitable for e-beam direct-write in patterning mask.
TiSixNy and TiSixOyNz as embedded materials for attenuated phase-shifting mask in 193 nm
(1999-05-01)
Lin, CM
;
Loong, WA
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
TiSixNy and TiSixOyNz were presented as new embedded materials for APSM in 193 nm lithography. TiSixNy films were formed by plasma sputtering of Ti (180 similar to 230 W) and Si (60 similar to 80 W) under Ar (50 seem) and nitrogen (4 similar to 6 seem). For required phase shift degree theta = 180 degrees, the calculated thickness d(180) of TiSixNy film is 82 similar to 93 nm. TiSixOyNz films were formed by plasma sputtering of Ti (200 similar to 240 W) and Si (60 similar to 80 W) under Ar (50 sccm), nitrogen (4 similar to 6 seem) and oxygen (0.2 similar to 0.7 seem). The d(180) of TiSixOyNz film is 92 similar to 105 nm. With the thickness d(180), the transmittance at visible wavelength (488, 632.8 nm) for optical alignment is 35 similar to 50% for TiSixNy and TiSixOyNz. Under BCl3:Cl-2=14:70 seem; chamber pressure 4 mtorr and RF power 1900 W, the dry etching selectivity of TiSixNy over DQN positive resist and fused silica, were found to be 2:1 and 4.8.1, respectively. A TiSixNy embedded layer with 0.6 mu m lines/space was successfully patterned.
TiSixOy as an absorptive shifter for embedded phase-shifting mask in 248 nm and the modification of R-T method for the determination of shifter's n and k
(1998-03-01)
Loong, WA
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Chen, CW
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Chang, YH
;
Lin, CM
;
Cui, Z
TiSixOy as an absorptive shifter (embedded layer) for attenuated phase-shifting mask (APSM) in 248 nm wavelength is presented. TiSixOy thin film was formed by plasma sputtering of Ti (25 similar to 55 W) and Si (200 similar to 250 W) under Ar (30 seem) and oxygen (0.1 similar to 0.4 sccm). For required phase shift degree theta=180 degrees, calculated thickness d(180) of TiSixOy Film is within the range of 87 similar to 120 nm depending on its reflectivity R, transmittance T, refractive index n and extinction coefficient k. Taguchi design of experiment has been applied to study the plasma etching selectivity of TiSixOy over APSM's substrate quartz (SiO2), under Cl-2:NF3=20:30 seem; 50 W and 60 mtorr, selectivity of 10:1 similar to 35:1 was observed. Modifications of reflectivity-transmittance (R-T) method have been developed for the determination of this absorptive shifter's n and k.