Browsing by Author "HSIEH, WY"

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INVESTIGATION ON THE DISTRIBUTION OF FLUORINE AND BORON IN POLYCRYSTALLINE SILICON SILICON SYSTEMS
(1995-06-01)
CHEN, TP
;
LEI, TF
;
CHANG, CY
;
HSIEH, WY
;
CHEN, LJ
The behaviors of fluorine in BF2+ implanted polycrystalline silicon (poly-Si) on silicon have been investigated in the annealing temperature range of 850 to 1100 degrees C. The distribution of fluorine atoms as functions of temperature and time have been monitored by the secondary ion mass spectroscopy (SIMS) and cross-sectional transmission electron microscopy (XTEM). The XTEM micrographs revealed that fluorine bubbles are distributed in the poly-Si and at the original poly-Si/Si interface after annealing. The locations of bubbles were found to correspond to the fluorine peaks in the SIMS depth-concentration profiles. The presence of the boron peak at the original poly-Si/Si interface is attributed to the gettering of boron atoms by the fluorine bubbles. Moreover, the boron profiles in the silicon substrates are sensitive to thermal budget due to the pileup of fluorine atoms at the poly-Si/Si interface. The pileup of fluorine at the poly-Si/Si interface leads to an enhancement of epitaxial regrowth of poly-Si films and. the formation of fluorine bubbles. Consequently higher surface dopant concentration and deeper junction depth were obtained.
LOW-TEMPERATURE GROWTH OF SILICON-BORON LAYER BY ULTRAHIGH-VACUUM CHEMICAL-VAPOR-DEPOSITION
(1994-04-04)
CHEN, TP
;
LEI, TF
;
LIN, HC
;
CHANG, CY
;
HSIEH, WY
A polycrystalline silicon-boron (Si-B) layer with a thickness of 180 nm was grown on recrystallized amorphous silicon in an ultrahigh vacuum chemical vapor deposition (UHV/CVD) system using pure SiH4 and B2H6 (1% in H-2). The growth temperature was as low as 550-degrees-C. Auger electron spectroscopy and secondary ion mass spectroscopy showed that the boron concentration is extraordinarily high (2 x 10(22) cm-3). From the analysis of transmission electron diffraction patterns, the phase of silicon hexaboride (SiB6) was found to be present in the as-deposited Si-B layer. After thermal annealing, most of the boron atoms in the Si-B layer were found to be immobile. The presence of SiB6 in the Si-B layer may lead to the reduction of boron diffusivity in the Si-B layer during thermal annealing.
SIMULTANEOUS OCCURRENCE OF MULTIPHASES IN THE INTERFACIAL REACTIONS OF ULTRAHIGH-VACUUM DEPOSITED HF AND CR THIN-FILMS ON (111)SI
(1993-03-08)
HSIEH, WY
;
LIN, JH
;
CHEN, LJ
;
交大名義發表
;
材料科學與工程學系
Simultaneous occurrence of multiphases were observed in the interfacial reactions of ultrahigh vacuum deposited Hf and Cr thin films on (111) Si by high-resolution transmission electron microscopy in conjunction with fast Fourier transform diffraction analysis and image simulation. For Hf/Si system, an amorphous interlayer, Hf5Si3 as well as FeB and CrB types of HfSi were found to form simultaneously in samples annealed at 530-degrees-C for 40-80 min. For Cr/Si system, an amorphous interlayer, Cr5Si3, CrSi, and CrSi2 were observed to form in samples annealed at 375-degrees-C for 30 min. The formation of multiphases appeared to be quite general in the initial stages of interfacial reactions of ultrahigh vacuum deposited refractory thin films. The results called for a reexamination of generally accepted ''difference'' in reaction sequence between bulk and thin-film couples.