Browsing by Author "You, HC"

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Fabrication of sub-60-nm contact holes in silicon dioxide layers
(2004-06-01)
Ko, FH
;
You, HC
;
Chu, TC
;
Lei, TF
;
Hsu, CC
We have developed a fabrication technique, comprising electron-beam writing, chemical shrinking, and silicon dioxide etching, for the fabrication of sub-60-nm contact holes. The dimensions of the contact holes after the electron-beam writing, chemical shrinkage, and plasma etching steps were 140, 93, and 53 nm, respectively. We carefully evaluated the critical process parameters, such as mixing-bake temperature, mixing-bake time, plasma etch selectivity, and the profile shapes. A higher mixing-bake temperature led to an overhang of the contact hole in the resist; the optimal mixing-bake conditions occur when heating at 110 degreesC for 70 s. A fluorinated mixture of gases (CHF3/CF4 = 1:1) was used to etch the nano-scale contact holes in the silicon dioxide layer. The formation of side-wall polymers during the plasma etch phase contributed further to the contact hole shrinkage in addition to resist chemical shrinkage. The ratio of the hole's perimeter to its area affects the shrinkage dimensions of the etch process, especially for smaller contact holes. The pattern reduction due to side-wall polymer deposition in etch process has the inverse relationship with the diameter of contact hole. (C) 2004 Elsevier B.V. All rights reserved.
Fullerene-incorporation for enhancing the electron beam resist performance for contact hole patterning and filling
(2006-04-03)
You, HC
;
Ko, FH
;
Lei, TF
;
材料科學與工程學系奈米科技碩博班
;
電子工程學系及電子研究所
The fullerene molecules such as C60 and C70 were incorporated in the commercial positive electron beam resist to investigate the performances for patterning and filling the contact holes at nanometer scale. The sensitivity, process window and contrast of the modified resist were improved, while the toluene dilution degraded the sensitivity. The electron beam dose affected the designed holes dimension, and the adulterated resist could print sub-50 nm holes pattern. We found the small amount (0.01-0.02% w/v) of fullerene molecules very effectively promoted the etch resistance and selectivity under fluoro-containing gases, and minimized the film stress. The etching resistance for C60 and C70 modification could be improved by 65% and 68%, respectively. Together with the fullerene-incorporated resist and the etching processes, the sub-50 nm contact hole could be achieved. In addition, the gap-filling and step coverage capability of titanium nitride into nanometer contact hole with chemical vapor deposition was better than physical vapor deposition. (c) 2005 Elsevier B.V. All rights reserved.
Improving the electrical integrity of Cu-CoSi2 contacted n(+)p junction diodes using nitrogen-incorporated Ta films as a diffusion barrier
(2002-11-01)
Yang, WL
;
Wu, WF
;
You, HC
;
Ou, KL
;
Lei, TF
The study on improving the electrical integrity Of Cu-CoSi2 contacted-junction diodes by using the reactively sputtered TaNx as a diffusion barrier is presented in this paper. In this study, the Cu(300 nm)-CoSi2 (50 nm)/n(+)p junction diodes were intact with respect to metallurgical reaction up to a 350 degreesC thermal annealing while the electrical characteristics started to degrade after annealing at 300 degreesC in N-2 ambient for 30 min. With the addition of a 50-nm-thick TaNx diffusion barrier between Cu and CoSi2, the junction diodes were able to sustain annealing up to 600 degreesC without losing the basic integrity of the device characteristics, and no metallurgical reaction could be observed even after a 750 degreesC annealing in furnace. In addition, the structure of TaNx layers deposited on CoSi2 at various nitrogen flow rates has been investigated. The TaNx film with small grain sizes deposited at nitrogen flow ratios exceeding 10% shows better barrier capability against Cu diffusion than the others.
Physical characterization and electrical properties of sol-gel-derived zirconia films
(2006)
You, HC
;
Fu-Hsiang, K
;
Lei, TF
;
材料科學與工程學系奈米科技碩博班
;
電子工程學系及電子研究所
We have developed a simple method for the preparation of ZrO2 ultrathin films; it involves a sequence of ZrCl4 precursor preparation in an ice bath, sol-gel spin-coating processing, baking, and annealing. The film thickness was controllable and tunable by altering the ZrCl4/hexanol ratio. High-resolution transmission electron microscopy (TEM) and thermal desorption spectrometry indicated that the fabricated ultrathin film was thermally stable at annealing temperatures as high as 900 degrees C. Diffraction patterns of TEM indicated that the films obtained at various annealing temperatures were amorphous. Electron spectroscopy for chemical analysis (ESCA) demonstrated an increase in the intensity of the signal for the Zr-O bonds upon increasing the annealing temperature, whereas those for the signals of carbon and chlorine decreased. The ESCA and TEM analyses also suggested that the thickness of the silicon dioxide film increased upon increasing the annealing temperature. The electrical properties, such as the breakdown field (12.5 MV/cm) and the gate current density (<10(-7) A/cm(2)), of the sol-gel-derived ZrO2 ultrathin films obtained after annealing at 900 degrees C suggested that they were good electrical insulators. These ZrO2 thin films are expected to behave as capacitors and as coatings for insulating films. (C) 2006 The Electrochemical Society.
Resist nano-modification technology for enhancing the lithography and etching performance
(2005-03-01)
You, HC
;
Ko, FH
;
Lei, TF
;
材料科學與工程學系奈米科技碩博班
;
電子工程學系及電子研究所
The fullerene molecules (i.e., C60 and C70) were incorporated in the SUMITOMO NEB-22 negative electron beam resist to investigate the lithographic and etching performances of the resist. The sensitivity, process window and contrast of the modified resist were found to be improved, while the dilution of resist degraded the sensitivity. The electron beam dose affected the designed line width, and the adulterated resist could print sub-50 nm pattern without the problem of line edge roughness. The etching selectivity of gas (CHF3/CF4) on silicon dioxide and resist, and gas (Cl-2/O-2) on poly-silicon and resist were evaluated. We found the small amount (0.01-0.02% w/v) of fullerene molecules very effectively promoted the etch resistance and selectivity. The fullerene-incorporated resist was used to pattern self-aligned metal silicides, and nickel silicide on poly-silicon exhibited lower sheet resistance. (c) 2005 Elsevier B.V. All rights reserved.