Appeal No. 1997-3335 Page 2
Application No. 08/315,454
BACKGROUND
Appellant's invention relates to a method of forming a dielectric film of barium and/or strontium
titanate on a microelectronic device and a method of forming a capacitive structure. Claims 1 and 8 are
illustrative:
1. A method of forming a barium and/or strontium titanate dielectric film on a microelectronic
device, said method comprising:
(a) preparing a precursor solution by combining a boron compound, a titanium compound, and
a precursor selected from the group consisting of barium compounds, strontium compounds, and
combinations thereof, such that the molar ratio of boron to titanium in said precursor solution is between
0.001 and 0.1;
(b) depositing and densifying one or more layers of said precursor solution to form a precursor
film on said device; and
(c) annealing said precursor film in an oxygen-containing atmosphere, thereby forming said
dielectric film comprising substantially uniformly distributed first and second phases, said first phase
containing a plurality of barium and/or strontium titanate grains and said second phase principally
comprising boron oxide, whereby said boron in said precursor apparently lowers the processing
temperature required to produce said titanate grains, and whereby boron additionally decreases the
dielectric leakage current observed for said dielectric film.
8. A method of forming a capacitive structure on a microelectronic device, said capacitive
structure having a dielectric laminate disposed between a first electrode and a second electrode, said
method comprising:
(a) forming said first electrode on a substrate;
(b) depositing two or more precursor films over said first electrode, each of said films
comprising titanium and at least one of barium and strontium, at least one of said films further
comprising boron in a ratio to said titanium of at least 0.001;
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