Praxair S.t. Technology, Inc.

Sony Corporation

Praxair Technology, Inc.

Materials Research Corporation

Alfred Snowman

Thomas J Hunt

Holger J Koenigsmann

Andre Desert

Paul S Gilman

Shailesh Kulkarni

Rajan Mathew

Bjoern Pigur

Charles R Fisher

Daniel R Marx

The present invention relates to methods for improving deposited film uniformity and controlling the erosion of sputter targets. Improved methods for achieving predetermined microstructure orientation in copper hollow cathode magnetron (HCM) sputter targets and targets prepared by such methods are disclosed.

Texture and grain size controlled hollow cathode magnetron targets and method of manufacture

The sputtering target has a design for uniformly depositing a material on a substrate. The target contains a circular disk; and the disk has a radius and a top surface. The top surface has a center region within the inner half of the radius, an outer ring-shaped region within the outer half of the radius and a base region separating the center region from the ring-shaped region. The outer ring-shaped region has a projection height for extending the life of the sputtering target. The center region has a projection height of less than the projection height of the outer ring-shaped region for increasing the sputtering deposition rate on the substrate adjacent the center region.

Ring-type sputtering target

The method is used to fabricate pure copper sputter targets. It includes first heating a copper billet to a temperature of at least 500&deg; C. The copper billet has a purity of at least 99.99 percent. Then warm working the copper billet applies at least 40 percent strain. Cold rolling the warm worked copper billet then applies at least 40 percent strain and forms a copper plate. Finally, annealing the copper plate at a temperature above about 250&deg; C. forms a target blank. The target blank has equiaxed grains having an average grain size of less than 40 &mgr;m. The grains of the target blank have (111), (200), (220) and (311) orientations with the amount of the grains having each of the orientations being less than 50 percent.

Fabrication and bonding of copper sputter targets

A method for determining actual size of internal target defects by ultrasonic inspection is provided in which the amplitude of signals generated by ultrasonic inspection are compared to metallurgical size measurements obtained through the use of optical microscopes or scanning electron microscopes or scanning election microscopes. From this comparison, a correlation factor may be obtained to determine the accuracy of the ultrasonic measurements. For a particular sputter target material, defect sizes obtained by ultrasonic inspection may then be multiplied by the correlation factor to determine the actual defect size for that defect. The use of actual defect sizes to determine defect sizes from ultrasonic inspection provides a more accurate determination of defect sizes than prior methods and provides a reliable means for accepting or rejecting targets for critical circuit manufacturing operations.

Determination of actual defect size in cathode sputter targets subjected to ultrasonic inspection

The present invention provides a high purity cobalt sputter target having a single phase h.c.p. structure and a magnetic permeability less than the intrinsic magnetic permeability of the material. Substantially pure cobalt is cast and slowly cooled, such as at a rate of 15&deg; C./min. Or less, to form a cast target of single phase h.c.p. crystallographic structure. This cast target is hot worked at a temperature of at least about 1000&deg; C. to impart a strain of about 65% or greater into the cobalt material, followed by a slow, controlled cooling to room temperature, such as at a rate of 15&deg; C./min. or less, to maintain the single phase h.c.p. crystallographic structure. The cooled target is then cold worked at substantially room temperature to impart a strain of about 5-20%. The sputter target of the present invention processed by this method has a magnetic permeability of less than about 9, grain sizes in the size range of about 70-160 &mgr;m, and average grain size of about 130 &mgr;m.

Method of making low magnetic permeability cobalt sputter targets

The invention relates to the manufacture of sputtering targets of tungsten-titanium alloy using high purity tungsten and titanium hydride powders. The powders are blended and placed in a containment vessel holding a die. The die is heated to a temperature of about 700.degree. C. to about 1000.degree. C. in an argon atmosphere while under pressure. The combination of temperature and pressure is high enough to dehydrate the titanium hydride and to remove the gases. The die is then heated to a higher temperature, in the range of about 1250.degree. C. to 1350.degree. C. while the pressure is increased so as to compact and alloy the powders. The pressure and temperature are held constant until there is no further movement of the ram. The resulting compacted alloy material is then machined to provide a sputtering target with a density between 96% and 100% of theoretical and a gas content less than 850 p.p.m. In a further feature of the present invention, a tungsten-titanium hydride powder may be used as the raw material for manufacturing the target. The raw materials of the present invention may be obtained by recycling used titanium targets or used tungsten-titanium targets.

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Englewood, NJ, United States of America

Alfred Snowman