CN-122003097-A - Method for forming semiconductor structure

Abstract

The invention provides a method for forming a semiconductor structure, which comprises the steps of providing a first substrate, carrying out one or more metal stacking operations on the first substrate, wherein the metal stacking operations comprise the steps of providing a second substrate, forming a metal layer on the second substrate, carrying out a separation operation on the second substrate and the metal layer, and transferring the metal layer to the first substrate. By adopting the technical scheme, the forming processes of the metal layer and the first substrate are mutually independent and do not influence each other, or when the metal stacking operation is carried out for a plurality of times, the forming processes of the metal layers are mutually independent and do not influence each other, so that the surface smoothness of the metal layer is improved, the contact effect of the metal layer and the lower film layer is improved after the metal layer is transferred onto the first substrate (for example, when the metal stacking operation is carried out for a plurality of times, the contact effect of the adjacent metal layers is improved, and the contact resistance can be reduced), and the performance of the semiconductor structure can be improved.

Inventors

• XUE XIAOFAN
• SI JIN
• WANG WEIGANG
• YANG JIAN

Assignees

• 中芯国际集成电路制造(上海)有限公司

Dates

Publication Date

20260508

Application Date

20241106

Claims (17)

1. 1. A method of forming a semiconductor structure, comprising: providing a first substrate; One or more metal stacking operations are performed on the first substrate, the metal stacking operations including providing a second substrate, forming a metal layer on the second substrate, performing a separation operation on the second substrate and the metal layer, and transferring the metal layer onto the first substrate.
2. 2. The method of claim 1, wherein the metal layer transferred onto the first substrate is a front metal layer and the metal layer to be transferred onto the first substrate is a current metal layer when the metal stacking operation is performed a plurality of times; during the metal stacking operation, the metal layer is transferred onto the first substrate, and the metal layer is attached to the metal layer.
3. 3. The method of claim 1, wherein the separating the second substrate from the metal layer and transferring the metal layer to the first substrate comprises at least one of: Mechanical stripping; And (5) heat stripping.
4. 4. The method of claim 3, wherein the metal layer comprises any one of a first type metal layer and a second type metal layer, and an adhesion between the first type metal layer and the second substrate is less than an adhesion between the second type metal layer and the second substrate; when the metal layer is a first type metal layer, a mechanical stripping mode is adopted to execute a separation operation on the second substrate and the metal layer, and the metal layer is transferred to the first substrate; when the metal layer is a second-type metal layer, a heat stripping mode is adopted to execute a separation operation on the second substrate and the metal layer, and the metal layer is transferred onto the first substrate.
5. 5. The method of forming a semiconductor structure as claimed in claim 4, wherein the material of the first type metal layer includes one or more of Al, W, N, co, mo, ti, ta, taN and MgO; the material of the second metal layer comprises one or more of Ag, au, pt, pd, coFeB and CoFe.
6. 6. The method of claim 3, wherein the step of performing a separation operation on the second substrate and the metal layer using a mechanical lift-off process and transferring the metal layer onto the first substrate comprises: Stripping the metal layer from the second substrate by a suction cup; And after the metal layer is peeled off from the second substrate, transferring the metal layer to the first substrate through the sucker.
7. 7. The method of claim 3, wherein in the step of providing a second substrate, the second substrate further has a buffer layer thereon, the metal layer being on the buffer layer; The step of performing a separation operation on the second substrate and the metal layer by using a thermal peeling manner, and transferring the metal layer onto the first substrate comprises the steps of: inverting the second substrate over the first substrate such that the metal layer is on the first substrate; After the second substrate is inverted on the first substrate, a heating operation is performed on the second substrate, and the buffer layer is decomposed to separate the second substrate and the metal layer.
8. 8. The method of claim 7, wherein the metal layer has a melting point higher than a decomposition temperature of the buffer layer.
9. 9. The method of claim 7, wherein the buffer layer comprises one or more of polypropylene carbonate, polyethylene carbonate, and a highly branched polymer.
10. 10. The method of claim 7, wherein the buffer layer has a thickness of 100nm to 1000nm along a normal direction of the second substrate surface.
11. 11. The method of claim 7, wherein the buffer layer is formed on the second substrate using a spin-on process.
12. 12. The method of claim 7, wherein in the step of providing the second substrate, the second substrate further has an adhesion layer thereon, the adhesion layer being located between the second substrate and the buffer layer.
13. 13. The method of claim 12, wherein the adhesion layer comprises one or more of Ge, gaAs, IGZO, WSe, WS2, and MoS 2.
14. 14. The method of claim 12, wherein the adhesion layer has a thickness of 10nm to 500nm along a normal direction of the second substrate surface.
15. 15. The method of claim 1, wherein after forming the metal layer on the second substrate, and before performing a separation operation on the second substrate and the metal layer, the method further comprises annealing the metal layer.
16. 16. The method of forming a semiconductor structure according to claim 1, wherein a plurality of metal stacking operations are performed on the first substrate to form an initial magnetic tunnel junction stack structure composed of a plurality of metal layers, the initial magnetic tunnel junction stack structure including a magnetic reference film, a tunneling oxide film, and a magnetic free film stacked in this order; Patterning the initial magnetic tunnel junction stack structure to form a magnetic tunnel junction stack structure.
17. 17. The method of forming a semiconductor structure according to claim 1, wherein in the step of providing the first substrate, a dielectric layer is formed on the first substrate, a conductive plug is formed in the dielectric layer, and a top of the conductive plug is exposed by the dielectric layer; The metal layer closest to the first substrate is electrically connected to the conductive plug.

Description

Method for forming semiconductor structure Technical Field The embodiment of the invention relates to the technical field of semiconductors, in particular to a method for forming a semiconductor structure. Background In semiconductor fabrication, it is often necessary to perform a number of different processes, which involve the formation of metal layers. The current methods of forming metal layers employ "high energy" fabrication processes based on vaporization of metal precursors, which typically involve bombardment of the contact region by hot metal atoms or clusters, which can cause damage to the contact surface of adjacent metal layers by kinetic energy transfer or chemical reaction between metal atoms and sub-atoms. Therefore, the performance of the semiconductor structure formed at present needs to be improved. Disclosure of Invention In view of the above, the embodiment of the invention provides a method for forming a semiconductor structure, which can improve the performance of the semiconductor structure. The embodiment of the invention provides a method for forming a semiconductor structure, which comprises the following steps: Providing a first substrate, performing one or more metal stacking operations on the first substrate, wherein the metal stacking operations comprise providing a second substrate, forming a metal layer on the second substrate, performing a separation operation on the second substrate and the metal layer, and transferring the metal layer onto the first substrate. Optionally, in the case of performing a plurality of metal stacking operations, the metal layer transferred onto the first substrate is a front metal layer, and the metal layer to be transferred onto the first substrate is a current metal layer; during the metal stacking operation, the metal layer is transferred onto the first substrate, and the metal layer is attached to the metal layer. Optionally, the manner of performing a separation operation on the second substrate and the metal layer and transferring the metal layer onto the first substrate includes at least one of: Mechanical stripping; And (5) heat stripping. Optionally, the metal layer includes any one of a first type metal layer and a second type metal layer, and an adhesion between the first type metal layer and the second substrate is smaller than an adhesion between the second type metal layer and the second substrate; when the metal layer is a first type metal layer, a mechanical stripping mode is adopted to execute a separation operation on the second substrate and the metal layer, and the metal layer is transferred to the first substrate; when the metal layer is a second-type metal layer, a heat stripping mode is adopted to execute a separation operation on the second substrate and the metal layer, and the metal layer is transferred onto the first substrate. Optionally, the material of the first type metal layer comprises one or more of Al, W, N, co, mo, ti, ta, taN and MgO; the material of the second metal layer comprises one or more of Ag, au, pt, pd, coFeB and CoFe. Optionally, the step of performing a separation operation on the second substrate and the metal layer by using a mechanical peeling manner, and transferring the metal layer onto the first substrate includes: Stripping the metal layer from the second substrate by a suction cup; And after the metal layer is peeled off from the second substrate, transferring the metal layer to the first substrate through the sucker. Optionally, in the step of providing a second substrate, the second substrate further has a buffer layer thereon, and the metal layer is located on the buffer layer; The step of performing a separation operation on the second substrate and the metal layer by using a thermal peeling manner, and transferring the metal layer onto the first substrate comprises the steps of: inverting the second substrate over the first substrate such that the metal layer is on the first substrate; After the second substrate is inverted on the first substrate, a heating operation is performed on the second substrate, and the buffer layer is decomposed to separate the second substrate and the metal layer. Optionally, the melting point of the metal layer is higher than the decomposition temperature of the buffer layer. Optionally, the material of the buffer layer includes one or more of polypropylene carbonate, polyethylene carbonate and a highly branched polymer. Optionally, the thickness of the buffer layer is 100nm to 1000nm along the normal direction of the second substrate surface. Optionally, a spin-coating process is used to form the buffer layer on the second substrate. Optionally, in the step of providing the second substrate, the second substrate further has an adhesion layer thereon, and the adhesion layer is located between the second substrate and the buffer layer. Optionally, the material of the adhesion layer includes one or more of Ge, gaAs, IGZO, WSe, WS2, and MoS 2. Optionally, the