Etching method for manufacturing semiconductor device

1. An etching device comprising:

a radiation source to apply a radiation to an etching aqueous solution;

an etching bath to hold the etching aqueous solution to be irradiated with the radiation from the radiation source provided outside the etching bath through a radiation window provided at an upper portion of the etching bath;

a first catalyst layer being different from the etching aqueous solution and provided in the etching bath in such a manner that a first surface of the first catalyst layer is in contact with an inner surface of the radiation window and a second surface of the first catalyst layer opposite to the first surface is exposed to the etching aqueous solution in the etching bath; and

a second catalyst layer disposed at an inner sidewall and an inner bottom of the etching bath,

wherein the first catalyst layer is made of titanium oxide (TiO 2 ), the radiation window is made of an insulating material which transmits the radiation, and the radiation is irradiated to an outer surface of the radiation window which is opposite to the inner surface of the radiation window with which the first catalyst is in contact.

2. The etching device according to claim 1 , further comprising,

a reflection portion to reflect the radiation emitted from the radiation source and apply the radiation to the etching aqueous solution.

3. The etching device according to claim 1 , wherein the radiation window is provided at an upper portion of the etching bath and transmits the radiation from the radiation source provided above the etching bath.

4. The etching device according to claim 1 , further comprising,

a liquid feed pipe to feed the etching aqueous solution to the etching bath, and the radiation source applies the radiation to the etching aqueous solution.

5. The etching device according to claim 1 , wherein each of areas of the first surface and the second surface is smaller than an area of a surface of the radiation window and each of shapes of the first surface and the second surface is different from a shape of the surface of the radiation window.

6. The etching device according to claim 1 , wherein the insulating material is one of magnesium fluoride, calcium fluoride and quartz glass.