| Summary: | 碩士 === 國立臺灣大學 === 電機工程學系研究所 === 86 === Several kinds of dielectric growth techniques, i.e.
sputtering of SiO2, PECVD
SiNx, E-Gun evaporation of SiO2, photo-CVD SiO2, LPD SiO2/PECVD a-SiHx, had
been applied to fabricate the InAs MOS capacitors. The
capacitor (T34) which was
processed by the chemical treatment H2SO4: H2O2 (9:1) etched for 2 minutes and
(NH4)2Sx rinsed for 10 minutes had less interface states and
fixed charges in the
dielectric film than all the others. The p-type inversion layer
was formed at the
SiO2/InAs interface by applying negative gate bias. The Auger
electron depth profiles
also show that more stable interface was formed by this chemical treatment.
The unpassivated InAs p-i-n diodes with various i-layer
thicknesses had been
fabricated and their temperature dependent I-V characteristics
were measured. It is
shown that the reverse currents of the diodes with 0.1, 0.5, 1
um i-layer thickness at —
0.5 V and 80 K are 4 x 10^-7, 2.7 x 10^-10, 5.5 x 10^-4 A,
respectively. The R0A value of
the diode with 0.5 um thick i-layer changes from 2.01 x 10^7
ohm*cm2 at 80 K to 0.070
ohm*cm2 at 300 K. The comparison of I-V characteristics between passivated and
unpassivated p-i-n diodes had been made, and it is clear that
the reverse current of the
passivated diode with gate bias — 5 V is much smaller than
that of the unpassivated
one. Finally, the spectral response and specific detectivity of
the unpassivated InAs p-
i-n diode with 0.5 um thick i-layer were measured. The peak of
the spectral response
was related to the bandgap of InAs below 200 K. The specific
detectivities of the
unpassivated InAs p-i-n diode with 0.5 um thick i-layer are
1.80 x 10^10 cmHz1/2W-1 at
20 K and 6.23 x 10^9 cmHz1/2W-1 at 80 K, respectively.
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