Hybrid semiconductor - magnetic spin based memory with low transmission barrier
OwnerMark Johnsoninventor
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Abstract
A nonvolatile hybrid memory cell is provided which includes magnetic and semiconductor components. The cell uses a thin film stack of ferromagnetic layers situated over a silicon substrate to store data in the form of variable impedance to a spin polarized current. The cell data is isolated by semiconductor isolation elements.
Claims27
A thin film hybrid magnetoelectronic spin-based memory cell comprising:
- i) a first thin film ferromagnetic layer with a first changeable magnetization state that can be altered to store a data value;
- wherein said first thin film ferromagnetic layer is coupled to a first electrode;
- ii) a second thin film ferromagnetic layer with a second non-changeable magnetization state;
- wherein said second thin film ferromagnetic layer is coupled to a second electrode;
- iii) a third thin film layer which is less than 1 micron in thickness and is situated between said first thin film ferromagnetic layer and said second thin film. ferromagnetic layer, said third thin film layer comprising a low transmnission barrier material with electron bands that are not significantly affected by an electron spin;
- wherein a spin polarized current flows in a path through a thin film stack situated over a silicon substrate, including at least said second electrode, said second thin film ferromagnetic layer, said third thin film layer, said first thin film ferromagnetic layer and said first electrode respectively;
- further wherein said data value can be determined by measuring a value of said variable spin polarized current which varies in accordance with a relationship between said first changeable magnetization state and said second non-changeable magnetization state.
The thin film hybrid magnetoelectronic spin-based memory cell of claim 9, wherein said write line uses a single polarity current pulse.
The thin film hybrid magnetoelectronic spin-based memory cell of claim 11, wherein a data value stored in such cell can only change state when a current pulse is present on both of said two overlapping write lines.
A thin film hybrid magnetoelectronic spin-based memory cell comprising:
- i) a first thin film ferromagnetic layer with a first magnetization state comprising permalloy and/or cobalt;
- ii) a second thin film ferromagnetic layer with a second magnetization state also comprising permalloy and/or cobalt;
- iii) a third thin film layer which is less than 1 micron in thickness and is situated between said first ferromagnetic layer and said second ferromagnetic layer, said third thin film layer comprising an aluminum based material;
- wherein said third thin film layer includes a low transmission barrier interface to said first ferromagnetic layer;
- a memory cell selector coupled to said thin film stack, said memory cell selector including a semiconductor based isolation element;
- wherein a spin polarized current flows through a thin film stack situated over a silicon substrate and the semiconductor based isolation element, including in a path including at least said second thin film ferromagnetic layer, said third thin film layer, and said first thin film ferromagnetic layer;
- further wherein a data value can be stored in the thin film hybrid magnetoelectronic spin-based memory cell by altering only said first magnetization state so as to change an impedance to a spin polarized current, which impedance varies in accordance with a relationship between said first magnetization state and said second magnetization state.
A thin film hybrid magnetoelectronic spin-based memory cell comprising:
- i) a first thin film ferromagnetic layer with a changeable magnetization state comprising permalloy and/or cobalt;
- ii) a second thin film ferromagnetic layer with a non-changeable magnetization state also comprising permalloy and/or cobalt;
- iii) a third thin film layer which is less than 1 micron in thickness and is situated between said first thin film ferromagnetic layer and said second thin film ferromagnetic layer, said third thin film layer comprising a material with equilibrium levels which are substantially equal for two different electron spins present in a spin polarized current;
- iv) a low transmission barrier interface between said third thin film layer and said first thin film ferromagnetic layer, said low transmission barrier interface being configured to effectuate a unipolar voltage output for the thin film hybrid magnetoelectronic spin-based memory cell;
- a semiconductor based isolation element adapted to isolate a data value stored in the thin film hybrid magnetoelectronic spin-based memory cell.
Dependencies are inferred from the claim text.