Corrosion resistant multilayer member
A corrosion resistant member to be exposed to a halogen-containing gas atmosphere or a halogen-containing gas plasma atmosphere, comprising a substrate and a plurality of layers deposited thereon including a layer of rare earth fluoride providing the outermost surface and a layer of rare earth oxide having a porosity of less than 5% underlying the rare earth fluoride layer.
1. A corrosion resistant member to be exposed to a halogen-containing gas atmosphere or a halogen-containing gas plasma atmosphere, comprising a substrate and a plurality of layers deposited thereon including a layer of rare earth fluoride providing the outermost surface and a layer of rare earth oxide having a porosity of less than 5% underlying the rare earth fluoride layer,
said rare earth fluoride layer being a thermally sprayed coating and having a thickness of 10 to 1,000 μm, and
said rare earth oxide layer being a thermally sprayed coating and having a thickness of 20 to 500 μm.
2. The corrosion resistant member of claim 1 wherein for each layer, the rare earth is a single element selected from the group consisting of Y, Sc, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.
3. The corrosion resistant member of claim 1 wherein for each layer, the rare earth is a mixture of at least two elements selected from the group consisting of Y, Sc, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.
4. The corrosion resistant member of claim 1 which consists essentially of the substrate, the rare earth oxide layer thereon, and the rare earth fluoride layer on the oxide layer.
5. The corrosion resistant member of claim 1 which is used in a semiconductor or flat panel display manufacturing apparatus.
6. The corrosion resistant member of claim 1 wherein the substrate is selected from among metals, metal alloys, and ceramics.
7. The corrosion resistant member of claim 6 wherein the substrate is selected from among Al, Mo, Ta, W, Hf, V, Zr, Nb, Ti, stainless steel, quartz, silicon nitride, alumina, and zirconia.
8. The corrosion resistant member of claim 1 wherein a metal or ceramic layer is formed on the substrate at a thickness of 10 to 500 μm.
9. The corrosion resistant member of claim 1 wherein a metal or ceramic layer is formed between the rare earth oxide layer and the rare earth fluoride layer at a thickness of 10 to 500 μm.
10. The corrosion resistant member of claim 1 wherein the plurality of layers have a multilayer structure including more than one set of rare earth oxide layer/rare earth fluoride layer, by forming a first rare earth oxide layer on the substrate, forming a first rare earth fluoride layer on the first oxide layer, forming a second rare earth oxide layer on the first fluoride layer, subsequently forming a second rare earth fluoride layer so that the outer most layer is a rare earth fluoride layer.