Electrochemical anodizing technique was used to form an interlevel alumina
insulator for multilevel aluminum metallization. The low dielectric constan
t of about 2.4 was reached by chemical etching of porous alumina films in a
nodizing solution. The interlevel insulator based on porous alumina had the
following parameters measured: the breakdown voltage was more than 400 V,
the leakage current at 15 V applied voltage was less than 10(-9) A/cm(2). T
he developed processing technique was tested for CMOS submicron technology.
The fabricated aluminum-porous alumina structure demonstrated a good chemi
cal and thermal stability, excellent adhesion to underlying and top layers.
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