Tungsten-boron sputter targets and films made thereby
AssigneeTosoh SMD, Inc.
InventorsEugene Y. Ivanov, Eduardo del Rio
Life of this patent
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Abstract
A Me-B based alloy spherical powder for use in a sputtering target including a metal powder selected from the group consisting of: Mo, W, Ta, Nb, Hf and Ti; a BN powder; and optionally a binary or ternary compound powder, as well as W/B sputter targets, alloys, and barrier/seed films made by such targets. A combined diffusion barrier layer is provided by sputter coating of a W/B sputter target either directly or by reactive sputtering with nitrogen wherein the B content of the alloy is about 0.5 wt %-10 wt %. The oxygen content of the alloy target is about 50 ppm or less. Preferably, the alloy is 99.995% pure.
Claims9
A method of manufacturing a Me-B based alloy solid compact for use in a sputtering target, comprising:
- (a) blending desired amounts of a metal powder comprising W, Ta, or Mo, a BN powder and optionally a Si3N4 ternary compound powder to form a composite,
- wherein:
- (i) when said metal powder comprises W or Ta, said metal powder and said BN powder are mixed in a mixing ratio from about 1:0.01 to 1:1, and
- (ii) when said metal powder comprises Mo and said optional tenary compound power comprises Si3N4, said metal powder, said BN powder, and said Si3N4 powder are mixed in a mixing ratio from about 3:1:1 to 6:1:3;
- (b) hot pressing said composite under vacuum to between about 1350° C.-1750° C. to make a target blank;
- and
- (c) providing a desired final shape and bonding of said target blank to an appropriate substrate, wherein a uniformity of said B content in said target blank is within +/−5%;
- wherein, when said metal powder comprises W and the hot pressing is conducted above 1600° C., B and a flow of N gas are provided by a decomposition reaction of said BN powder and the flow of N gas removes surface impurities from said W powder.
A method of manufacturing of W/B composite target comprising of following steps:
- a) blending desired amounts of W powder and BN powder to produce a W/BN blend, wherein said W/BN blend is devoid of B powder, wherein said W powder and said BN powder are mixed in a mixing ratio from about 1:0.01 to 1:1;
- b) hot pressing said W/BN blend under vacuum at temperature above 1600° C. to make a target blank, wherein surface impurities are removed from said W powder of said W/BN blend by flow of N gas;
- and
- c) providing a desired final shape and bonding of said target blank to an appropriate substrate to form said W/B composite target, wherein a final N content in said W/B composite target is below 20 ppm.
A method of covering a trench using a target blank:
- said method comprising covering, by atomizing said target blank, a trench having at least one wall in an interlayer dielectric formed on a substrate to form a barrier film on said trench and said at least one wall during fabrication of a semiconductor device, wherein said barrier film is a W/B/N alloy film having a boron content of about 1 wt %-10 wt % and an oxygen content of about 50 mass ppm or less;
- said target blank is manufactured from a Me-B based alloy solid compact using a method comprising:
- (a) blending desired amounts of a metal powder and a BN powder to form a composite,
- wherein said metal powder comprises W and said metal powder and said BN powder are mixed in a mixing ratio from about 1:0.01 to 1:1;
- (b) hot pressing said composite under vacuum to between about 1350° C.-1750° C. to make a target blank;
- (c) providing a desired final shape and bonding of said target blank to an appropriate substrate, wherein a uniformity of said B content in said target blank is within +/−5%;
- wherein, when the hot pressing is conducted above 1600° C., B and a flow of N gas are provided by a decomposition reaction of said BN powder and the flow of N gas removes surface impurities from said W powder.
Dependencies are inferred from the claim text.