Browsing by Author "CHENG, KL"

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CHARACTERIZATION OF H-2/N-2 PLASMA PASSIVATION PROCESS FOR POLY-SI THIN-FILM TRANSISTORS (TFTS)
(1995-06-01)
TSAI, MJ
;
WANG, FS
;
CHENG, KL
;
WANG, SY
;
FENG, MS
The effects of nitrogen additives on the plasma hydrogenation of polycrystalline silicon thin film transistors (poly-Si TFTs) have been investigated with various radio-frequency (RF) power densities, substrate heating temperature, gas flow rates, as well as chamber pressures. The nitrogen-containing hydrogen (H-2/N-2) plasma treatments show better passivation effects on the electrical characteristics of the poly-Si TFTs than the pure H-2 hydrogenation. It is attributed to the passivation effect of the nitrogen radicals themselves and the promotion of the hydrogen plasma generation due to the radical collision. The passivation effects have been enhanced by properly chosen RF power density, gas flow rate and chamber pressure. Furthermore, the H-2/N-2 plasma were also utilized to passivate the poly-Si TFTs with different grain structures.
EFFECT OF SIH4/CH4 FLOW RATIO ON THE GROWTH OF BETA-SIC ON SI BY ELECTRON-CYCLOTRON-RESONANCE CHEMICAL-VAPOR-DEPOSITION AT 500-DEGREES-C
(1995-01-09)
LIU, CC
;
LEE, CY
;
CHENG, KL
;
CHENG, HC
;
YEW, TR
INFLUENCE OF IMPLANT CONDITION ON THE TRANSIENT-ENHANCED DIFFUSION OF ION-IMPLANTED BORON IN SILICON
(1992-03-15)
JUANG, MH
;
WAN, FS
;
LIU, HW
;
CHENG, KL
;
CHENG, HC
Under high-dosage boron implant, the implant condition was found to be important for reducing the transient-enhanced diffusion of boron in Si and forming shallow p + n junction with good rectifying characteristics as well as high dopant concentration in the diffused region. The BF2+-implantation resulted in not only an excellent dopant activation but also a reduced anomalous diffusion due to the formation of amorphous layer and the scarce defects underneath the amorphous/crystalline (a/c) interface. The B+-implanted crystalline samples manifested a poor activation efficiency, and a largely anomalous diffusion at the high temperature with prolonged-time annealing ascribed to much damage induced by the high-dose implant. The B+-implanted pre-Si+-amorphized samples also displayed severely transient-enhanced diffusion in spite of the good dopant activation.
MICROCRYSTALLINE beta-SIC GROWTH ON SI BY ECR-CVD AT 500 degrees C
(1995)
CHENG, KL
;
LIU, CC
;
CHENG, HC
;
LEE, CY
;
YEW, TR
MICROCRYSTALLINE SIC FILMS GROWN BY ELECTRON-CYCLOTRON-RESONANCE CHEMICAL-VAPOR-DEPOSITION AT LOW-TEMPERATURES
(1995-10-01)
CHENG, KL
;
CHENG, HC
;
LIU, CC
;
LEE, C
;
YEW, TR
The characteristics of microcrystalline silicon carbide (mu c-SiC) films deposited using an electron cyclotron resonance chemical vapor deposition system at low temperatures have been investigated. The effect of microwave (MW) power on the SiC crystallinity is studied. According to the results of Fourier transform infrared absorption spectra, plan-view transmission electron microscopy, and the plasmon loss peaks in X-ray photoelectron spectroscopy, Si-C bonds form when the MW power is above 500 W for deposition at 500 degrees C. The SiC crystallinity improves monotonically with MW power. The amount of incorporated carbon atoms in the grown films increases with MW power up to the concentration of 50% at 1500 W. The dependence of the surface morphology and the mean roughness of the films on MW power is examined using the contact mode atomic force microscopy.
MICROCRYSTALLINE SIC FILMS GROWN BY ELECTRON-CYCLOTRON-RESONANCE CHEMICAL-VAPOR-DEPOSITION AT LOW-TEMPERATURES
(1995-10-01)
CHENG, KL
;
CHENG, HC
;
LIU, CC
;
LEE, C
;
YEW, TR
The characteristics of microcrystalline silicon carbide (mu c-SiC) films deposited using an electron cyclotron resonance chemical vapor deposition system at low temperatures have been investigated. The effect of microwave (MW) power on the SiC crystallinity is studied. According to the results of Fourier transform infrared absorption spectra, plan-view transmission electron microscopy, and the plasmon loss peaks in X-ray photoelectron spectroscopy, Si-C bonds form when the MW power is above 500 W for deposition at 500 degrees C. The SiC crystallinity improves monotonically with MW power. The amount of incorporated carbon atoms in the grown films increases with MW power up to the concentration of 50% at 1500 W. The dependence of the surface morphology and the mean roughness of the films on MW power is examined using the contact mode atomic force microscopy.
SUPPRESSION OF ANOMALOUS DIFFUSION OF ION-IMPLANTED BORON IN SILICON BY LASER PROCESSING
(1992-04-01)
JUANG, MH
;
WAN, FS
;
LIU, HW
;
CHENG, KL
;
CHENG, HC
Anomalous diffusion of ion-implanted boron in silicon has been suppressed by using the laser annealing (LA) technique. For the rapid thermal annealing process, the high-dosage boron implant significantly enhanced the anomalous diffusion of boron in Si largely due to increased density of interstitial clusters. The mechanism that electrically active dopants contribute to diffusion is confirmed. The dopant activation is primarily determined from the heating process rather than the holding time interval. Hence, the optimum annealing regime, attaining high-performance shallow p+-n junctions, is to increase the dopant activation efficiency during the temperature-ramping process as well as to shorten the holding interval. Having an ultrahigh heating rate, the LA technique serves as an excellent annealing scheme to significantly suppress the anomalous diffusion and considerably promote the dopant activation.
VERY-LOW TEMPERATURE DEPOSITION OF POLYCRYSTALLINE SI FILMS FABRICATED BY HYDROGEN DILUTION WITH ELECTRON-CYCLOTRON-RESONANCE CHEMICAL-VAPOR-DEPOSITION
(1995-02-01)
WANG, KC
;
CHENG, KL
;
JIANG, YL
;
YEW, TR
;
HWANG, HL
Characteristics of polycrystalline silicon films deposited both on SiO2 and Coming 7059 glass substrates are presented in this paper. The silicon films were deposited by a hydrogen dilution method using electron cyclotron resonance chemical vapor deposition at 250 degrees C without any thermal or laser annealing. The hydrogen dilution ratio was between 90% and 99%. The geometric configuration and surface morphology of polycrystalline silicon films were studied by atomic force microscopy. The largest grain size of the deposited silicon films; identified by plan-view transmission electron microscopy dark-field imaging, was about 1 mu m. From Raman spectrum, the crystalline fraction of polycrystalline silicon films was identified to be nearly 100%. The polycrystalline silicon was found to be preferentially [111]- and [110]-oriented, from the X-ray diffraction pattern.