Anodized titanium material and method for producing the same
An anodized titanium material includes a titanium base material and an anodized titanium layer. The anodized titanium layer is provided on a surface of the titanium base material. The anodized titanium layer includes a porous first anodized titanium layer. The anodized titanium layer has a withstand voltage at 25° C. of 500 V or more, a Vickers hardness of 200 or more, a film thickness of 20 μm or more and less than 80 μm, an arithmetic average roughness Ra of a surface of less than 1.6 μm, and a maximum height roughness Rz of the surface is less than 6.3 μm. In both of a section perpendicular to a thickness direction of the first anodized titanium oxide layer and the surface, no pore sections having a shape capable of including a circle having a diameter of 0.5 μm or more are observed.
1. An anodized titanium material comprising:
a titanium base material; and
an anodized titanium layer provided on a surface of the titanium base material, wherein
the anodized titanium layer comprises
a porous first anodized titanium layer;
the anodized titanium layer has a withstand voltage at 25° C. of 500 V or more, a Vickers hardness of 200 or more, a film thickness of 20 μm or more and less than 80 μm, an arithmetic average roughness Ra of a surface of less than 1.6 μm, and a maximum height roughness Rz of the surface is less than 6.3 μm;
in a section perpendicular to a thickness direction of the first anodized titanium layer and in the surface of the first anodized titanium layer, no pore sections having a shape capable of including a circle having a diameter of 0.5 μm or more are observed; and
the first anodized titanium layer comprises a plurality of tubular pores extending in a direction intersecting the surface of the anodized titanium layer,
wherein the anodized titanium layer further comprises
a second anodized titanium layer provided between the titanium base material and the first anodized titanium layer; and
a fluorine content (unit: atomic %) in the second anodized titanium layer is lower than a fluorine content (unit: atomic %) in the first anodized titanium layer.
2. The anodized titanium material according to claim 1 , wherein the anodized titanium layer has a withstand voltage at 150° C. higher than a withstand voltage at 25° C.
3. The anodized titanium material according to claim 1 , further comprising a metal base material made of a metal other than titanium, wherein
the titanium base material is provided on a surface of the metal base material.
4. The anodized titanium material according to claim 1 , wherein the anodized titanium material is used as a vacuum apparatus member and the anodized titanium layer is exposed to a plasma atmosphere.
5. An electrostatic chuck used in a plasma etching apparatus, the electrostatic chuck comprising:
the anodized titanium material according to claim 1 , wherein
the anodized titanium layer is provided on an outermost surface of the electrostatic chuck and exposed to a plasma atmosphere.
6. A cooling plate used in a plasma etching apparatus, the cooling plate comprising:
the anodized titanium material according to claim 1 ; and
a refrigerant channel provided in an internal part of the cooling plate and allowing a refrigerant to flow, wherein
the anodized titanium layer is provided on an outermost surface of the cooling plate.
7. A shower head used in a plasma etching apparatus, the shower head comprising:
a wall member comprising the anodized titanium material according to claim 1 and defining an internal space, wherein
the wall member comprises at least a bottom surface;
the wall member comprises
a gas introduction port for flowing a processing gas for plasma etching into the internal space, and
a plurality of gas discharge holes provided on the bottom surface and allowing the processing gas to flow out of the internal space; and
the anodized titanium layer is exposed at least at inner peripheral surfaces of the gas discharge holes.