Semiconductor device and method for fabricating the same
A method for fabricating a semiconductor device includes the steps of: 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 the MTJ stack to form a MTJ.
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 and part of the channel layer to form an MTJ, wherein a sidewall of the MTJ comprises a curve.
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, wherein the first channel layer comprises a U-shape.
3. 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.
4. 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.
5. The method of claim 2 , wherein the first channel layer and the second channel layer comprise different materials.
6. The method of claim 2 , wherein the first channel layer and the second channel layer comprise different etching rates.
7. 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.
8. The method of claim 7 , wherein the cap layer and the dielectric layer comprise different materials.
9. 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.