Browsing by Author "Lin, HK"

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Evidence of birefringence and anomalous electromagnetic-pulse propagation in an organic light-emitting diode
(2005-06-05)
Tai, SC
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Chern, JL
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Huang, YC
;
Tseng, MR
;
Lin, HK
dHigh-speed electromagnetic characteristics of an organic light-emitting diode (OLED) are explored in this paper. When a high-frequency (similar to 14 GHz) microwave pulse is injected into an OLED, the pulse is split into two peaks: one peak is delayed by 1.725 ns and another one is advanced by 0.183 ns, which also suggests the existence of an extremely low-speed group velocity. The effective thickness of the OLED sample is similar to 355.8 nm and, as a result, the effective index of refraction is similar to 107 when the splitting phenomenon occurs. (c) 2005 Wiley Periodicals, Inc.
Expanding the process window and reducing the optical proximity effect by post-exposure delay
(2001-08-01)
Ku, CY
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Shieh, JM
;
Chiou, TB
;
Lin, HK
;
Lei, TF
In this investigation, a novel idea had been proposed to expand the process window and reduce the optical proximity effect (OPE) by employing post-exposure delay (PED). Our previous work presented a model to specify the resist linewidth according to PED time based on the neutralization mechanism of organic base and photogenerated acid. Based on the model, the exposure latitude and depth of focus can be extended for various pattern sizes by applying PED on linewidth broadening. Moreover, the dense-iso critical dimension bias, which is caused by OPE, can also be reduced when PED is performed. (C) 2001 The Electrochemical Society. [DOI: 10.1149/1.1383557] All rights reserved.
Focus measurement with a simple pattern design
(2001-06-01)
Ku, CY
;
Lei, TF
;
Lin, HK
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
The increasingly smaller depth of focus of advanced lithographic tools requires that the position of best focus be determined to ensure accuracy and efficiency. We present what we believe is a novel bar in bar that is drawn on a conventional chrome binary mask to translate focal errors into center-to-center shifts of outer and inner bars. An overlay measurement tool can easily measure this shift. A symmetrical center-to-center shift against best focus is created during defocus, and this shift can be well fitted by a second-order polynomial equation. Simply differentiating the fitted equation leads to an accurate and reliable focus value, with a maximum error of less than 0.05 mum. The proposed technique can also be employed to evaluate the tilt, field curvature, and astigmatism of advanced lithographic tools. (C) 2001 Optical Society of America.
New overlay pattern design for real-time focus and tilt monitor
(2000)
Ku, CY
;
Lei, TF
;
Shieh, JM
;
Chiou, TB
;
Lin, HK
The reduced depth of focus (DOF) caused by higher numerical aperture (NA) is making the accuracy of best focus measurement increasingly important. A new overlay pattern is developed herein to precisely measure the best focus of lithographic tools. Specially designed "bar-in-bar" (BIB) was employed to obtain the best focus by using the opposite shifting direction of inner and outer bars when defocused. The inner and outer bars are composed of various pattern sizes. When defocused, the shrinkage of the smaller patterns is more significant than that of the larger patterns, thus causing the center of gravity to shift. The distribution and pattern sizes are optimized to obtain high reproducibility and sensitive position shifting for various defocus conditions. Employing the special BIB pattern, the best focus, tilting and field curvature can be easily measured via the conventional overlay measurement tool. By adding the special BIB to the scribe lanes of the production wafers, the best focus and tilting of the stepper can be obtained when measuring a layer-to-layer overlay shift, and can then be fed back to the stepper as a reference for following processing wafers.
Postexposure delay effect on linewidth variation in base added chemically amplified resist
(2000-10-01)
Ku, CY
;
Shieh, JM
;
Chiou, TB
;
Lin, HK
;
Lei, TF
To elucidate the linewidth variation caused by postexposure delay (PED) in resist films, the distribution of photogenerated acid, the role of additional base component, and the affect of exposure energy were investigated in tert-butoxycarbonyl protected-type chemically amplified positive deep ultraviolet resist. The resist system included an N-methyl pyrrolidone organic base which was evaluated via KrF excimer laser lithography. Using various line-and-space patterns formed with a KrF scanner, this work also investigated the change of linewidth caused by the delay time between exposure and postexposure bake. Experimental results indicate that the linewidth broadened immediately following exposure and became a constant value rather than continuously expanding for various pattern sizes. Based on the mechanism of neutralizing organic base and photogenerated acid, a model was established to describe the linewidth according to FED time. Moreover, the effect of exposure energy on linewidth variation was investigated to not only assess the influence of exposure energy but also clarify the relationship between linewidth broadening and delay rime. Experimental analysis demonstrates that the exposure latitude and depth of focus can be improved by employing FED. (C) 2000 The Electrochemical Society. S0013-4651(99)09-090-4. All rights reserved.