Semiconductor device and method for fabricating the same

1. A method for fabricating a semiconductor device, comprising:

forming a first inter-metal dielectric (IMD) layer on a substrate;

forming a first metal interconnection and a second metal interconnection in the first IMD layer;

forming a channel layer on the first metal interconnection and the second metal interconnection;

forming a magnetic tunneling junction (MTJ) stack on the channel layer; and

removing part of the MTJ stack to form an MTJ.

2. The method of claim 1 , wherein the step of forming the channel layer comprises:

forming a dielectric layer on the first IMD layer;

removing the dielectric layer to form an opening;

forming a first channel layer and a second channel layer in the opening; and

planarizing the first channel layer and the second channel layer.

3. The method of claim 2 , wherein the first channel layer comprises a U-shape.

4. The method of claim 2 , further comprising:

forming the MTJ stack on the first channel layer and the second channel layer; and

removing the MTJ stack, the second channel layer, and the first channel layer.

5. The method of claim 2 , further comprising removing the MTJ stack, the second channel layer, the first channel layer, and the dielectric layer after forming the MTJ stack.

6. The method of claim 2 , wherein the first channel layer and the second channel layer comprise different materials.

7. The method of claim 2 , wherein the first channel layer and the second channel layer comprise different etching rates.

8. The method of claim 2 , further comprising:

forming a cap layer on the MTJ, the channel layer, and the dielectric layer; and

forming a second IMD layer on the cap layer.

9. The method of claim 8 , wherein the cap layer and the dielectric layer comprise different materials.

10. The method of claim 1 , wherein the MTJ comprises:

a free layer on the channel layer;

a barrier layer on the free layer; and

a pinned layer on the barrier layer.