High purity refractory metal powders and their use in sputtering targets which may have random texture

1. A method for making a sputtering target comprising the steps of:

a. encapsulating at least one mass of metal powder that has at least about 95% by weight of particles exhibiting a particle size ranging from about 10 to about 1000 μm, with at least about 10 percent by weight of particles having a particle size greater than about 150 μm, in a container configured for defining at least a portion of a sputtering target body; and

b. hot isostatically pressing the at least one mass of metal powder to form a resulting densified mass having an initial crystallographic texture, while the at least one mass of metal powder is in the container, wherein the hot isostatically pressing step is performed under conditions so that the initial crystallographic texture achieved in the resulting densified mass is an essentially theoretically random and generally uniform crystallographic texture, wherein the method is devoid of any step of altering the initial crystallographic texture substantially throughout the resulting densified mass after the step of hot isostatically pressing and prior to sputtering, and

wherein the method includes a step of making a refractory metal powder using a method comprising the steps of:

a. locating an initial mass of refractory metal powder having an initial content of oxygen in a reactor;

b. locating within the reactor, spaced apart from the initial mass of refractory metal powder, a mass of a scavenging metal, wherein the mass of the scavenging metal and the initial mass of refractory metal powder are not blended together;

c. heating within the reactor to a scavenging temperature for causing at least a portion of the scavenging metal to at least partially vaporize and react with at least a portion of the initial content of oxygen to form a scavenging metal oxide with at least a portion of the scavenging metal; and

d. separating the scavenging metal oxide from the initial mass of refractory metal powder so that a resulting mass of refractory metal powder is formed that has a resulting content of oxygen that is less than the initial content of oxygen, wherein the at least one mass of metal powder comprises at least a portion of the resulting mass of refractory metal powder, and wherein the resulting densified mass (i) has an oxygen content below about 125 PPM, and/or (ii) comprises the scavenging metal in an amount below about 10 PPM.

2. The method of claim 1 , wherein the resulting mass of refractory metal powder comprises at least about 99.95 percent by weight of tantalum.

3. The method of claim 1 , wherein the initial content of oxygen is greater than about 300 ppm by weight.

4. The method of claim 1 , wherein the initial mass of refractory metal powder is in a bed having a depth ranging from about 0.3 cm to about 3.5 cm.

5. The method of claim 1 , wherein the scavenging metal is magnesium, is present in the reactor in the form of flakes, or both.

6. The method of claim 1 , wherein the heating step includes heating in the reactor at a temperature of about 800 to about 1000° C. for a time of about 30 minutes to about 2 hours.

7. A method for making a sputtering target comprising the steps of:

a. making a refractory metal powder using a method comprising the steps of:

1. locating an initial mass of refractory metal powder having an initial content of oxygen in a reactor,

2. locating within the reactor, spaced apart from the initial mass of refractory metal powder, a mass of a scavenging metal, wherein the mass of the scavenging metal and the initial mass of refractory metal powder are not blended together,

3. heating within the reactor to a scavenging temperature for causing at least a portion of the scavenging metal to at least partially vaporize and react with at least a portion of the initial content of oxygen to form a scavenging metal oxide with at least a portion of the scavenging metal, and

4. separating the scavenging metal oxide from the initial mass of refractory metal powder so that a resulting mass of refractory metal powder is formed that has a resulting content of oxygen that is less than the initial content of oxygen;

b. encapsulating the resulting mass of refractory metal powder that has at least about 95% by weight of particles exhibiting a particle size ranging from about 10 to about 1000 μm, with at least about 10 percent by weight of particles having a particle size greater than about 150 μm, in a container configured for defining at least a portion of a sputtering target body; and

c. hot isostatically pressing the resulting mass of refractory metal powder to form a resulting densified mass having an initial crystallographic texture, while the resulting mass of refractory metal powder is in the container, wherein the hot isostatically pressing step is performed under conditions so that the initial crystallographic texture achieved in the resulting densified mass is an essentially theoretically random and generally uniform crystallographic texture, wherein the method is devoid of any step of altering the initial crystallographic texture substantially throughout the resulting densified mass after the step of hot isostatically pressing and prior to sputtering.

8. The method of claim 7 , wherein the method is free of any further thermomechanical processing step.