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US 6,582,641 B1Granted
Apparatus and method for making metal oxide sputtering targets
AssigneePraxair S.T. Technology, Inc.
InventorsChi-Fung Lo, John Turn
Life of this patent
Estimating the term…
Abstract
An apparatus and process for making metal oxide sputtering targets from volatile and thermally unstable metal oxide powder by hot-pressing the metal oxide powder in a graphite die assembly having a ceramic barrier sleeve disposed therein to isolate the metal oxide powder from the graphite die assembly components.
Claims15
Apparatus for making metal oxide sputtering targets, comprising:
- a graphite die assembly, including a graphite ring and a pair of opposing graphite punches, defining a die cavity for hot-pressing a powdered metal oxide target starting material which includes an indium oxide and tin oxide into a metal oxide sputtering target;
- and
- a barrier sleeve lining said graphite die assembly die cavity and providing a barrier between said graphite die assembly and the powdered metal oxide target starting material, said barrier sleeve being made of a material selected from the group consisting of Al2O3, MgO, ZrO2, SiC and Si3N4, and being capable of withstanding hot-pressing at a temperature of at least 1100° C.;
- whereby said barrier sleeve substantially prevents a reducing gas from penetrating to the powdered metal oxide target starting material, said barrier sleeve being substantially unreactive with the powdered target starting material during hot pressing, and said powdered target starting material being volatile and thermally unstable during hot pressing.
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A process for making metal oxide sputtering targets, comprising the steps of:
- providing a graphite die assembly, including a graphite ring and a pair of opposing graphite punches, defining a die cavity with a barrier sleeve lining said die cavity, said barrier sleeve being made of a ceramic selected from the group consisting of Al2O3, MgO, ZrO2, SiC and Si3N4 and combinations thereof, and said barrier sleeve being capable of withstanding hot-pressing at a temperature of at least 1100 ° C.;
- loading a powdered metal oxide sputtering target starting material including an indium oxide and tin oxide into said die cavity such that said powdered starting material is substantially completely surrounded by said barrier sleeve;
- and
- hot-pressing the powdered metal oxide sputtering target starting material at an elevated temperature of at least 1100° C. in the graphite die assembly to produce a metal oxide target blank, wherein the target starting material is volatile and thermally unstable at the elevated temperature and the barrier sleeve substantially prevents a reducing gas from penetrating therethrough to the target starting material during the hot-pressing step.
1 more element
Dependencies are inferred from the claim text.