| Summary: | 碩士 === 國立成功大學 === 電機工程研究所 === 83 === The effects of thermal process and surface passivation on
Schottky barrier height of several kinds of metal-n/GaAs were
investigated.Using MBE, n-GaAs buffer layer was grown between N-
type GaAs substrate and metal to improve the performance of
schottky barrier height. The conceration of this buffer layer
can''t be so high to form ohmic contact.Three different
concentrations 1E16 cm-3,5*10E16 cm-3 and 1*10E17cm-3 are
discussed. We deposite several kinds of metal as Ag, Pt, and Al
on buffer layer by evaporation method and compare the
performance of hat the property of Schottky contact of Al is
worse than that of Ag due to the large chemical activity of Al
in our experiement although the Al contact is so far the best
in the presented document. Next,the Schottky Diode is annealed
under different condition,ie, 300C/5min, 400C/1min, 550C/20s.
We observe that the barrier height is enhanced after annealing
because the formation of the interfacial stable compound (Ga,Al)
As, which has been examined by scanning Auger microscopy and X-
ray.And we can get an optimum barrier height at 400C/1min. But
the Ag contact opposites this condition. At last, the interface
stable density effects on the electrical properties was
studied. Schottky barriers have been prepared on the sulfide-
treated GaAs. We found that the interface trap density was
reduced by this passivation and the barriers are more sensitive
to the metal work function.
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