Browsing by Author "Chang, MN"

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An investigation of scanning capacitance microscopy on iron-contaminated p-type silicon
(2001-09-01)
Chang, MN
;
Chang, TY
;
Pan, FM
;
Wu, BW
;
Lei, TF
Scanning capacitance microscopy (SCM) is employed to examine iron-contaminated p-type Si samples. For slightly contaminated samples, a dc voltage of -0.8 V, applied between the sample and the conductive tip, induces positive trapped charges. Owing to the existence of these charges, the region containing trapped charges exhibits an obviously low dC/dV signal. According to contact-mode atomic force microscopy results, the surface, morphology has little effect on the SCM signal. The experimental results indicate that SCM is capable of detecting the distribution of oxidation-related. defects which cannot otherwise be easily observed by atomic force microscopy and transmission electron microscopy. (C) 2001 The Electrochemical Society.
Influence of annealing sequence on p(+)/n junction images studied by scanning capacitance microscopy
(2004)
Chang, MN
;
Wan, WW
;
Chen, CY
;
Lai, JH
;
Liang, JH
We have successfully employed scanning capacitance microscopy (SCM) operated under low photoperturbation to investigate electrical junction profiles in low-energy BF2+-implanted silicon wafers treated by various annealing sequences. Differential capacitance images reveal that rapid thermal annealing (RTA) followed by furnace annealing (FA) treatments (RTA+FA) can result in a narrower junction width and a shallower electrical junction depth than FA followed by RTA treatments (FA+RTA). Experimental results also indicate that the wider junction of the FA+RTA treated sample is due to the shallower concentrated distribution of electrically activated boron atoms upon annealing. Subtle correlations between electrical junctions and annealing conditions are discussed. (C) 2004 The Electrochemical Society.
Investigation of localized breakdown spots in thin SiO(2) using scanning capacitance microscopy
(2005)
Wang, SD
;
Chang, MN
;
Chen, CY
;
Lei, TF
;
電子工程學系及電子研究所
Scanning capacitance microscopy (SCM) was employed to observe the oxide breakdown sites. The localized breakdown spots obviously exhibit low differential capacitance signals. The observed area of the breakdown spots approximately ranges from 6 nm to 13 nm in lateral direction. According to contact-mode atomic force microscopy (AFM) image, the surface morphology has little effect on the SCM signal.
Observation of differential capacitance images on slightly iron-contaminated p-type silicon
(2002-08-01)
Chang, MN
;
Chen, CY
;
Pan, FM
;
Chang, TY
;
Lei, TF
Scanning capacitance microscopy (SCM) is employed to study defect distribution induced by iron contamination on p-type silicon wafers. For slightly contaminated samples, SCM reveals that iron contamination induces interface traps in the defect region. Interface traps perturb significantly the depletion behavior of the silicon surface. Iron contamination also decreases the lifetime and increases the density of minority carriers in the defect region. The defects induced by iron contamination exhibit an obvious bias-dependent SCM contrast. By differential capacitance images, one can examine the defect density distribution. The influence of these microscale defects on the electrical characteristics of the metal oxide semiconductor (MOS) capacitor cannot be observed by conventional capacitance-voltage measurement. (C) 2002 The Electrochemical Society.
Observation of localized breakdown spots in thin SiO2 films using scanning capacitance microscopy
(2005)
Wang, SD
;
Chang, MN
;
Chen, CY
;
Lei, TF
;
電子工程學系及電子研究所
Scanning capacitance microscopy (SCM), combined with atomic force microscopy (AFM), was employed to investigate the dielectric breakdown phenomena in thin SiO2 films. The localized breakdown spots can be clearly imaged by the SCM technique. The spots exhibit signals with low differential capacitance (dC/dV) due to high conductivity. The diameters of these breakdown spots were approximately from 6 to 13.5 nm. Moreover, according to the corresponding AFM images, their surface morphology showed little change after the occurrence of oxide breakdown. (c) 2005 The Electrochemical Society. All rights reserved.
Porous silicon light-emitting diode with tunable color
(1997-05-01)
Chen, YA
;
Chen, BF
;
Tsay, WC
;
Laih, LH
;
Chang, MN
We successfully combined porous silicon and amorphous silicon together to fabricate a light-emitting diode, whose emitting color was tunable with different applied voltage. When the applied voltage increased from 30 to 90 V, the emitting color of the device could change from red to blue. (C) 1997 Elsevier Science Ltd.
Selective growth of carbon nanotube on scanning probe tips by microwave plasma chemical vapor deposition
(2004-01-01)
Pan, FM
;
Liu, YB
;
Chang, Y
;
Chen, CY
;
Tsai, TG
We have selectively grown carbon nanotubes on the probe tip of an atomic force microscope by microwave plasma chemical vapor deposition. The catalyst domain was defined on the tip apex of an Si based scanning probe by local electric field induced oxidation of a TiN cap layer, under which the cobalt catalyst layer was predeposited on the probe surface. High resolution atomic force microscopy images of an SiO2 trench pattern are demonstrated using the carbon nanotube tip. The nanotube tip fabrication method is simple and compatible with existing thin film process technology. (C) 2004 American Vacuum Society.
Variations of differential capacitance in SrBi2Ta2O9 ferroelectric films induced by photoperturbation
(2005-02-28)
Leu, CC
;
Chien, CH
;
Chen, CY
;
Chang, MN
;
Hsu, FY
In this letter, we demonstrated the impact of illumination on the differential capacitance variation of a strontium bismuth tantalite (SBT) capacitor during scanning capacitance microscopy measurements. It was found that illumination with a stray light of laser in an atomic force microscope could perturb the dC/dV signals of the samples. We attribute this phenomenon to the generation of free carriers by the photon absorptions via defect traps in the SBT thin film. Therefore, this present work suggests that the effect of laser illumination must be carefully taken into consideration whenever a field-sensitive technique is employed to analyze the properties of a ferroelectric material. (C) 2005 American Institute of Physics.