Methods of testing sputtering target materials

A method for testing a plurality of sputtering targets, comprising:

• for each target of the plurality of targets:
• defining a plurality of positions across at least a portion of the sputtering target;
• sequentially irradiating at each of the positions of said plurality of positions with sonic energy, and sequentially detecting amplitudes of individual echoes induced by said sonic energy;
• processing the amplitudes to sort the individual echoes into a first group indicative of inhomogeneities in the sputtering target, and a second group which does not indicate inhomogeneities in the sputtering target;
• sorting the individual echoes of the first group into clusters, with the clusters being defined as individual echoes from adjacent positions of the plurality of positions;
• generating an integrated amplitude for the individual echoes associated with a common cluster;
• and
• calculating a figure-of-merit for the sputtering target from the integrated amplitudes associated with the sputtering target;
• and
• sorting the plurality of sputtering targets based on the respective figure-of-merits of the sputtering targets.

A method for testing a material having a form and shape of a sputtering target, comprising:

• checking the material for size and location of inhomogeneities within the material by:
• determining an erosion profile for the sputtering target;
• defining a plurality of positions across at least a portion of the material;
• sequentially irradiating at each of the positions of said plurality of positions with sonic energy, and sequentially detecting amplitudes of echoes induced by said sonic energy;
• and
• for only the material within the erosion profile:
• processing the amplitudes to sort the echoes into a first group indicative of inhomogeneities in the material, and a second group which does not indicate inhomogeneities in the material;
• sorting the echoes of the first group into clusters, with the clusters being defined as echoes from adjacent positions of the plurality of positions;
• generating an integrated amplitude for the echoes associated with a common cluster;
• and
• comparing the integrated amplitudes with reference inhomogeneities to estimate the size of the inhomogeneities and depth of the inhomogeneities within the material.

A method for testing a material having a form and shape of a sputtering target, comprising:

• checking the material for size and location of inhomogeneities within the material by:
• defining a plurality of positions across at least a portion of the material;
• sequentially irradiating at each of the positions of said plurality of positions with sonic energy, and sequentially detecting amplitudes of echoes induced by said sonic energy;
• processing the amplitudes to sort the echoes into a first group indicative of inhomogeneities in the material, and a second group which does not indicate inhomogeneities in the material;
• sorting the echoes of the first group into clusters, with the clusters being defined as echoes from adjacent positions of the plurality of positions;
• generating an integrated amplitude for the echoes associated with a common cluster;
• and
• comparing the integrated amplitudes with reference inhomogeneities to estimate the size of the inhomogeneities and depth of the inhomogeneities within the material;
• determining an erosion profile for the sputtering target;
• and
• for at least one of the inhomogeneities, estimating the point during target lifetime at which said at least one inhomogeneity will be exposed.