High density refractory metals and alloys sputtering targets
AssigneeH.C. Starck GmbH
InventorsPrabhat Kumar, Charles Wood, Gary Rozak, Steven A. Miller, Glen Zeman, Rong-Chein Richard Wu
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Abstract
The present invention is directed to a process for producing high density, refractory metal products via a press/sintering process. The invention is also directed to a process for producing a sputtering target and to the sputtering target so produced.
Claims9
A method of forming a sputtering-target plate that is sputterable to form highly uniform, low-resistivity films of a refractory metal selected from the group consisting of molybdenum, tungsten, an alloy of molybdenum and tungsten, molybdenum alloyed with a metal other than tungsten, and tungsten alloyed with a metal other than molybdenum, the method comprising:
- cold isostatically pressing a powder of the refractory metal at a pressure selected from the range of 15,000 psi to 36,000 psi to form a pressed product;
- heating the pressed product under vacuum at a rate of about 20° F. to about 120° F. to a first temperature selected from the range of about 300° F. to about 1000° F. and holding the pressed product at the first temperature for a period selected from the range of about 1 hour to about 38 hours;
- heating the pressed product under vacuum at a rate of about 20° F. to about 120° F. from the first temperature to a second temperature selected from the range of about 1500° F. to about 2800° F. and holding the pressed product at the second temperature for a period selected from the range of about 1 hour to about 38 hours;
- heating the pressed product under vacuum at a rate of about 20° F. to about 120° F. from the second temperature to a third temperature selected from the range of about 3000° F. to about 4000° F. and holding the pressed product at the third temperature for a period selected from the range of about 1 hour to about 38 hours;
- allowing the pressed product to cool to room temperature;
- and
- machining the pressed product to a desired size, thereby forming the sputtering-target plate that is sputterable to form highly uniform, low-resistivity films of the refractory metal, the sputtering-target plate having a density greater than 97% of a theoretical density of the refractory metal.
Dependencies are inferred from the claim text.