Planar or tubular sputtering target and method for the production thereof
View Patent ↗Planar or tubular sputtering targets made of a silver base alloy and at least one further alloy component selected from indium, tin, antimony, and bismuth accounting jointly for a weight fraction of 0.01 to 5.0% by weight are known. However, moving on to ever larger targets, spark discharges are evident and often lead to losses especially in the production of large and high-resolution displays having comparatively small pixels. For producing a sputtering target with a large surface area on the basis of a silver alloy of this type, which has a surface area of more than 0.3 m 2 as a planar sputtering target and has a length of at least 1.0 m as a tubular sputtering target, and in which the danger of spark discharges is reduced and thus a sputtering process with comparatively high power density is made feasible, the invention proposes that the silver base alloy has a crystalline structure with a mean grain size of less than 120 μm, an oxygen content of less than 50 wt.-ppm, a content of the impurity elements, aluminum, lithium, sodium, calcium, magnesium, barium, and chromium, each of less than 0.5 wt.-ppm, and a metallic purity of at least 99.99% by weight.
1. A sputtering target comprising a silver base alloy and at least one further alloy component selected from indium, tin, antimony, and bismuth, wherein the at least one further alloy component is present in a total weight fraction of 0.01 to 5.0% by weight, and having a crystalline structure with a mean grain size of less than 120 μm, an oxygen content of less than 50 mg/kg, a content of the impurity elements, aluminum, lithium, sodium, calcium, magnesium, barium, and chromium, each of less than 0.5 mg/kg, and a metallic purity of at least 99.99% by weight, with the proviso that when the sputtering target is planar the target has a surface area of more than 0.3 m 2 , and with the proviso that when the sputtering target is tubular the target has length of at least 1.0 m.
2. The sputtering target according to claim 1 , wherein the oxygen content of the silver base alloy is less than 20 mg/kg.
3. The sputtering target according to claim 2 , wherein the content of each of the impurity elements is less than 0.1 mg/kg.
4. The sputtering target according to claim 2 , wherein the total content of the impurity elements is less than 0.5 mg/kg.
5. The sputtering target according to claim 2 , wherein the total content of the impurity elements is less than 0.1 mg/kg.
6. The sputtering target according to claim 2 , wherein the mean grain size is less than 100 μm.
7. The sputtering target according to claim 1 , wherein the oxygen content of the silver base alloy is less than 10 mg/kg.
8. The sputtering target according to claim 1 , wherein the content of each of the impurity elements is less than 0.1 mg/kg.
9. The sputtering target according to claim 7 , wherein the mean grain size is less than 100 μm.
10. The sputtering target according to claim 1 , wherein the total content of the impurity elements is less than 0.5 mg/kg.
11. The sputtering target according to claim 10 , wherein the mean grain size is less than 100 μm.
12. The sputtering target according to claim 1 , wherein the total content of the impurity elements is less than 0.1 mg/kg.
13. The sputtering target according to claim 1 , wherein the mean grain size is less than 100 μm.