Deposição e caracterização de filmes finos de We WSi e estudo da estabilidade termica do contato Schottky sobre GaAs

AUTOR(ES)
DATA DE PUBLICAÇÃO

1992

RESUMO

This dissertation presents a study of the physical and electrical characteristics of W and WSi x thin films as a function of the deposition parameters, done RF magnetron sputtering. Thin films of about 200 nm thickness were deposited on GaAs and SiO/2Si substrates. The depositions were done after a base-pressure of about 6.10-7 Torr was achieved. The deposition parameters were Ar pressure and RF power, varying from 6 to 50 mTorr and 300 to 700 Watts, respectively. The films were characterized about resistivity C4-point probe), phases CXRD) and composition CAES). before and after rapid thermal annealing CRTA) treatments. W/GaAs and WSi x/GaAs diodes were fabricated using photography procedure and plasma etching for definition of Schotlky gales with 200 μ diameter, on n type. (100). GaAs substrates with resistivity of 10-1 Ocm (n = 1016 cm-3). The thermal stabilily of lhe diodes was studied by annealing different samples by RTA in different conditions. These annealing were performed under an arsenic over-pressure ambient. The deposition of W under high Ar pressure produced films of high resistivity (β phase) and diodes with low thermal slability (about 600 C). W films of low resistivity (ά-W( phase) were obtained after reducing the pressure and power af the deposition process. The diodes made with these films presented a thermal slability up to 820"C/10s or 850"C/5s wilh barrier heighl of 0.77 eV and ideallity factor of 1.06.

ASSUNTO(S)

semicondutores engenharia eletrica filmes finos

ACESSO AO ARTIGO

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