Browsing by Author "WAN, FS"

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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.
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.