TRANSPARENT CONDUCTIVE FILM AND METHOD FOR MANUFACTURING THE TRANSPARENT CONDUCTIVE FILM, AND SPUTTERING TARGET USED IN THE METHOD
An object of the present invention is to provide a tin oxide target suitable for forming a transparent conductive film by a sputtering method, in particular, DC sputtering method, DC pulse sputtering method, AC sputtering method, and MF sputtering method. The present invention relates to a sputtering target for use in forming a transparent conductive film by a sputtering method, the sputtering target containing tin oxide as a main component and containing, as dopants, copper element and at least one element selected from the dopant group A consisting of niobium, tungsten, tantalum, bismuth, and molybdenum.
1 . A sputtering target for forming a transparent conductive film by a sputtering method,
the sputtering target containing tin oxide as a main component and containing, as dopants, copper element and at least one element selected from the dopant group A consisting of niobium, tungsten, tantalum, bismuth, and molybdenum.
2 . The sputtering target according to claim 1 , wherein the following expressions (1) to (3) are satisfied when the total amount of the elements of the dopant group A in the sputtering target is expressed by M A (at. %), the amount of the copper element is expressed by M Cu , (at. %), and the amount of the tin element contained in the sputtering target is expressed by M Sn (at. %).
0.8<( M Sn )/( M Sn +M A +M Cu )<1.0 (1)
0.001<( M A )/( M Sn +M A +M Cu )<0.15 (2)
0.001<( M Cu )/( M Sn +M A +M Cu )<0.1 (3)
3 . The sputtering target according to claim 1 , wherein the following expressions (8) to (10) are satisfied when the total amount of the elements of the dopant group A in the sputtering target is expressed by M A (at. %), the amount of the copper element is expressed by M Cu (at. %), and the amount of the tin element contained in the sputtering target is expressed by M Sn (at. %).
0.85<( M Sn )/( M Sn +M A +M Cu )<0.99 (8)
0.005<( M A )/( M Sn +M A +M Cu )<0.10 (9)
0.001<( M Cu )/( M Sn +M A +M Cu )<0.08 (10)
4 . The sputtering target according to claim 1 , which has a relative density of 80% or higher and a surface sheet resistivity of 9×10 6 Ω/square or lower.
5 . A transparent conductive film containing tin oxide as a main component,
the transparent conductive film containing, as dopants, copper element and at least one element selected from the dopant group A consisting of niobium, tungsten, tantalum, bismuth, and molybdenum.
6 . The transparent conductive film according to claim 5 , wherein the following expressions (4) to (6) are satisfied when the total amount of the elements of the dopant group A is expressed by M A (at. %), the amount of the copper element is expressed by M Cu , (at. %), and the amount of the tin element contained in the transparent conductive film is expressed by M Sn (at. %).
0.8<( M Sn )/( M Sn +M A +M Cu )<1.0 (4)
0.001<( M A )/( M Sn +M A +M Cu )<0.15 (5)
0.001<( M Cu )/( M Sn +M A +M Cu )<0.1 (6)
7 . The transparent conductive film according to claim 5 , wherein the following expressions (11) to (13) are satisfied when the total amount of the elements of the dopant group A is expressed by M A (at. %), the amount of the copper element is expressed by M Cu , (at. %), and the amount of the tin element contained in the transparent conductive film is expressed by M Sn (at. %).
0.85<( M Sn )/( M Sn +M A +M Cu )<0.99 (11)
0.005<( M A )/( M Sn +M A +M Cu )<0.10 (12)
0.001<( M Cu )/( M Sn +M A +M Cu )<0.08 (13)
8 . The transparent conductive film according to claim 5 , which has a specific resistance of 5×10 −2 Ωcm or lower.
9 . The transparent conductive film according to claim 5 , which has a carrier density of 8×10 19 /cm 3 or higher.
10 . The transparent conductive film according to claim 5 , which has a thickness of 1 μm or smaller.
11 . The transparent conductive film according to claim 5 , which has a light absorptivity, as measured at a wavelength of 1,064 nm, of 3.8% or higher.
12 . The transparent conductive film according to claim 5 , which has been formed by a sputtering method.
13 . A member for displays which has the transparent conductive film according to claim 5 .
14 . A process for producing a transparent conductive film, the process comprising forming a transparent conductive film by a sputtering method using the sputtering target according to claim 1 .