Magnetic tunnel junction (MTJ) element and its fabrication process
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsTsann Lin, Ya-Ling Lee
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Abstract
A magnetic tunnel junction (MTJ) element is provided. The MTJ element includes a buffer layer, a seed layer disposed over the buffer layer, a first ferromagnetic layer disposed over the seed layer, a tunnel barrier layer disposed over the first ferromagnetic layer and a second ferromagnetic layer disposed over the tunnel barrier layer. The seed layer includes a Cobalt (Co)-based film. The buffer layer includes cobalt (Co) and hafnium (Hf). The buffer layer is alloyed with chromium and has chromium content up to 20 at. %. The MTJ element in accordance with the present disclosure exhibits a low resistance desired for a low-power write operation, and a high TMR coefficient desired for a low bit-error-rate (BER) read operation.
Claims20
A magnetic tunnel junction element (MTJ), comprising:
- a buffer layer;
- a seed layer disposed over the buffer layer;
- a first ferromagnetic layer disposed over the seed layer;
- a tunnel barrier layer disposed over the first ferromagnetic layer;
- and
- a second ferromagnetic layer disposed over the tunnel barrier layer,
- wherein the seed layer comprises a Cobalt (Co)-based film,
- wherein the buffer layer comprises cobalt (Co) and hafnium (Hf), and
- wherein the buffer layer is alloyed with chromium and has chromium content up to 20 at. %.
A semiconductor device, comprising:
- a bottom electrode;
- a buffer layer disposed over the bottom electrode;
- a seed layer disposed over the buffer layer;
- at least one ferromagnetic layer disposed over the seed layer;
- and
- a top electrode disposed over the at least one ferromagnetic layer,
- wherein the seed layer comprises a Cobalt (Co)-based film,
- wherein the buffer layer comprises cobalt (Co) and hafnium (Hf), and
- wherein the buffer layer is alloyed with chromium and has chromium content up to 20 at. %.
A semiconductor device, comprising:
- a bottom electrode;
- a buffer layer disposed over the bottom electrode;
- a seed layer disposed over the buffer layer;
- at least one ferromagnetic layer disposed over the seed layer;
- a cap layer disposed over the at least one ferromagnetic layer;
- and
- a top electrode disposed over the cap layer,
- wherein the cap layer comprises MgO,
- wherein the seed layer comprises a Cobalt (Co)-based film,
- wherein the buffer layer comprises cobalt (Co) and hafnium (Hf), and
- wherein the buffer layer is alloyed with chromium and has chromium content up to 20 at. %.
Dependencies are inferred from the claim text.