Semiconductor structure and manufacturing method thereof

1 . A method of manufacturing a semiconductor structure, comprising:

providing a substrate;

forming a base pattern on the substrate, wherein the forming a base pattern on the substrate comprises: forming an isolation layer on a surface of the substrate;

patterning the isolation layer, and forming an isolation structure, wherein the isolation structure comprises a plurality of bar grooves arranged in parallel; forming a bit line in each of the plurality of bar grooves; and forming a first metal silicide layer on the surface of the bit line, the base pattern comprises a plurality of bit lines arranged in parallel, and the isolation structure is disposed between adjacent two of the plurality of bit lines;

forming a plurality of semiconductor pillars arranged in a direction of the bit line on a surface of each of the plurality of bit lines, wherein the bit line is electrically connected to the plurality of semiconductor pillars;

forming a gate-all-around structure on a surface of each semiconductor pillar, wherein the gate-all-around structure comprises a first insulating layer, a gate structure layer, and a second insulating layer that are sequentially disposed on a side surface of each semiconductor pillar; and

forming a first wire, a magnetic tunnel junction, and a second wire that are stacked sequentially above a surface of the gate-all-around structure, wherein the first wire is electrically connected to the semiconductor pillar.

2 . The method of manufacturing a semiconductor structure according to claim 1 , wherein

the semiconductor pillar comprises a first source-drain region at a bottom, a channel region in a middle, and a second source-drain region at a top;

the first source-drain region and the second source-drain region are formed through doping with a first-type dopant, and the channel region is formed through doping with a second-type dopant; and

the first source-drain region is at least partially located below a lower surface of the gate structure layer, and when the first source-drain region is all located below the lower surface of the gate structure layer, an upper surface of the first source-drain region is flush with the lower surface of the gate structure layer; and the second source-drain region is at least partially located above an upper surface of the gate structure layer, and when the second source-drain region is all located above the upper surface of the gate structure layer, a lower surface of the second source-drain region is flush with the upper surface of the gate structure layer.

3 . The method of manufacturing a semiconductor structure according to claim 1 , wherein

the forming a plurality of semiconductor pillars arranged in a direction of the bit line on a surface of each of the plurality of bit lines comprises:

forming a silicon-based semiconductor layer on surfaces of the plurality of bit lines;

forming a protective layer on a surface of the silicon-based semiconductor layer; and

patterning the silicon-based semiconductor layer and the protective layer, to form the plurality of semiconductor pillars in the direction of the bit line, wherein a top surface of each of the plurality of semiconductor pillars is provided with a patterned protection structure.

4 . The method of manufacturing a semiconductor structure according to claim 1 , wherein

air gaps are formed on sidewalls of the bit line, and the forming the bit line in each of the plurality of bar grooves comprises:

forming a sacrificial layer on sidewalls of the plurality of bar grooves;

filling each of the plurality of bar grooves with a metal material; and

removing the sacrificial layer, and forming the air gaps.

5 . The method of manufacturing a semiconductor structure according to claim 1 , wherein

the forming a gate-all-around structure on a surface of the semiconductor pillar comprises:

forming the first insulating layer on surfaces of the plurality of bit lines and a surface of the isolation structure, wherein the first insulating layer surrounds bottoms of the semiconductor pillars;

forming gate dielectric layers, wherein each of the gate dielectric layers covers an exposed part of one of the semiconductor pillars;

forming a gate conductive layer on a surface of the first insulating layer and side surfaces of the gate dielectric layers, wherein the gate dielectric layer and the gate conductive layer are taken as the gate structure layer; and

forming the second insulating layer on a surface of the gate conductive layer, wherein the second insulating layer fills a gap between adjacent two of the plurality of semiconductor pillars.

6 . The method of manufacturing a semiconductor structure according to claim 5 , wherein

the forming a gate conductive layer on a surface of the first insulating layer and side surfaces of the gate dielectric layers comprises:

forming a primary conductive layer on the surface of the first insulating layer and the side surfaces of the gate dielectric layers; and

patterning the primary conductive layer, and forming a plurality of gate conductive layers extending along a direction perpendicular to the bit line.

7 . The method of manufacturing a semiconductor structure according to claim 5 , after the forming a gate-all-around structure on a surface of the semiconductor pillar, further comprises:

implanting metal ions into the semiconductor pillar, and forming a second metal silicide layer.

8 . The method of manufacturing a semiconductor structure according to claim 7 , wherein

the forming a second metal silicide layer comprises:

removing a patterned protection structure on a top of each semiconductor pillar;

depositing a metal layer at the top of each semiconductor pillar; and

performing high-temperature annealing on the metal layer, and the metal layer and the top of the semiconductor pillar forming the second metal silicide layer.

9 . The method of manufacturing a semiconductor structure according to claim 1 , wherein

the forming a magnetic tunnel junction above a surface of the gate-all-around structure comprises:

forming a first wire layer on the gate-all-around structure, wherein the first wire layer comprises a plurality of first wires independent of each other and a first spacer disposed between adjacent first wires, and each first wire is electrically connected to each semiconductor pillar;

forming a magnetic tunnel junction layer on the first wire layer, wherein the magnetic tunnel junction layer comprises a plurality of magnetic tunnel junctions independent of each other, and each magnetic tunnel junction is electrically connected to each first wire; and

forming a second wire layer on the magnetic tunnel junction layer, wherein the second wire layer comprises a plurality of second wires independent of each other, and a second spacer disposed between adjacent second wires, each second wire is electrically connected to each magnetic tunnel junction, and the second spacer fills gaps between adjacent magnetic tunnel junctions.

10 . The method of manufacturing a semiconductor structure according to claim 9 , wherein

the forming a first wire layer on the gate-all-around structure comprises:

forming a first spacing layer on the gate-all-around structure;

patterning the first spacing layer, and forming a plurality of via holes, wherein each via hole exposes a top of the semiconductor pillar;

forming a first contact structure in each of the plurality of via holes;

forming a first conductive layer on the first spacing layer and a plurality of first contact structures;

patterning the first conductive layer, and forming a plurality of first sub-wires, wherein each first sub-wire is electrically connected to each first contact structure, and the first sub-wire and the first contact structure are taken as the first wire; and

forming a second spacing layer, wherein the second spacing layer fills a gap between adjacent two of the plurality of first sub-wires, and the first spacing layer and the second spacing layer are taken as the first spacer.

11 . The method of manufacturing a semiconductor structure according to claim 9 , wherein

the forming a magnetic tunnel junction layer on the first wire layer comprises:

forming a primary fixed layer on the first wire layer;

forming a primary non-magnetic insulating layer on the primary fixed layer;

forming a primary non-fixed layer on the primary non-magnetic insulating layer; and

patterning the primary non-fixed layer, the primary non-magnetic insulating layer, and the primary fixed layer, and forming the plurality of magnetic tunnel junctions independent of each other, wherein the magnetic tunnel junction comprises a fixed layer, a non-magnetic insulating layer, and a non-fixed layer that are disposed sequentially, a direction of magnetic moment of the non-fixed layer is changeable, and a direction of magnetic moment of the fixed layer is fixed.

12 . The method of manufacturing a semiconductor structure according to claim 9 , wherein

the forming a second wire layer on the magnetic tunnel junction layer comprises:

forming a third spacing layer, wherein the third spacing layer fills a space between adjacent two of the plurality of magnetic tunnel junctions, and covers the magnetic tunnel junction layer;

forming via holes penetrating through the third spacing layer, wherein each via hole exposes the magnetic tunnel junction;

forming a second contact structure in each of the plurality of via holes;

forming a second conductive layer on the third spacing layer and the second contact structures;

patterning the second conductive layer, and forming a plurality of second sub-wires, wherein the second contact structure is electrically connected to the second sub-wire, and the second contact structure and the second sub-wire are taken as the second wire; and

forming a fourth spacing layer, wherein the fourth spacing layer fills a gap between adjacent two of the plurality of second sub-wires, and the third spacing layer and the fourth spacing layer are taken as the second spacer.