Method for forming semiconductor structure

Abstract

A method for forming a semiconductor structure includes: providing a substrate; forming a first electromagnetic film on the substrate; forming a tunnel film on a surface of the first electromagnetic film; performing a first heating process to heat-treat the first electromagnetic film and the tunnel film; and forming a second electromagnetic film on the surface of the tunnel film after heat-treating the first electromagnetic film and the tunnel film. This improves the performance of a magnetic tunnel junction.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to a method for forming a semiconductor structure. Background Art

[0002] MRAM (Magnetic Random Access Memory) is a non-volatile magnetic random access memory. It combines the high read and write speeds of static random access memory (SRAM) with the high integration density of dynamic random access memory (DRAM) while consuming far less power than DRAM. Compared to flash memory, MRAM's performance does not degrade over time. Due to these characteristics, MRAM is known as universal memory and is considered a potential replacement for SRAM, DRAM, EEPROM, and Flash.

[0003] Unlike traditional random access memory chip manufacturing technology, data in MRAM is not stored in the form of charge or current, but rather as a magnetic state, and is sensed by measuring resistance without disturbing the magnetic state. MRAM uses a magnetic tunnel junction (MTJ) structure to store data. Generally speaking, an MRAM cell consists of a transistor (1T) and a magnetic tunnel junction (MTJ) to form a storage cell. The magnetic tunnel junction (MTJ) structure includes at least two electromagnetic layers and an insulating layer used to separate the two electromagnetic layers. Current flows perpendicularly from one electromagnetic layer through the insulating layer to the other electromagnetic layer, or "through". One of the electromagnetic layers is a fixed magnetic layer that fixes the electrode in a specific direction through a strong fixed field. The other electromagnetic layer is a freely rotating magnetic layer that holds the electrode in one direction.

[0004] However, the performance of the magnetic tunnel junction prepared by the prior art is poor. Summary of the Invention

[0005] The technical problem solved by the present invention is to provide a method for forming a semiconductor structure, so as to improve the lattice structure and interface state of the magnetic tunnel junction while reducing the mutual diffusion of materials caused by heat treatment and improving the heating process accuracy, thereby improving the performance of the magnetic tunnel junction.

[0006] In order to solve the above technical problems, the technical solution of the present invention provides a method for forming a semiconductor structure, including: providing a substrate; forming a first electromagnetic film on the substrate; forming a tunnel film on the surface of the first electromagnetic film; using a first heating process to heat-treat the first electromagnetic film and the tunnel film; after heat-treating the first electromagnetic film and the tunnel film, forming a second electromagnetic film on the surface of the tunnel film.

[0007] Optionally, the first heating process includes a first in-situ heating process.

[0008] Optionally, the first in-situ heating process includes an in-situ laser heating process or an in-situ infrared heating process.

[0009] Optionally, the process parameters of the first in-situ heating process include: a temperature range of 200°C to 350°C.

[0010] Optionally, the first in-situ heating process is an in-situ infrared heating process, and the process parameters of the first in-situ heating process further include: a pressure range of 1×10 -10 millitorr~1×10 -8 mTorr; infrared energy density range is 10 W / cm2 to 30 W / cm2.

[0011] Optionally, the method further includes: before forming the tunnel film, using a second heating process to heat-treat the first electromagnetic film.

[0012] Optionally, the second heating process includes a second in-situ heating process.

[0013] Optionally, the second in-situ heating process includes one of an in-situ laser heating process or an in-situ infrared heating process.

[0014] Optionally, the process parameters of the second in-situ heating process include: a temperature range of 250°C to 400°C.

[0015] Optionally, the second in-situ heating process is an in-situ infrared heating process, and the process parameters of the second in-situ heating process further include: a pressure range of 1×10 -10 millitorr~1×10 -8 mTorr; infrared energy density range is 10 W / cm2 to 30 W / cm2.

[0016] Optionally, the method further includes: after forming the second electromagnetic film, using a third heating process to heat treat the second electromagnetic film.

[0017] Optionally, the third heating process includes a third in-situ heating process.

[0018] Optionally, the third in-situ heating process includes an in-situ laser heating process or an in-situ infrared heating process.

[0019] Optionally, the process parameters of the third in-situ heating process include: a temperature range of 250°C to 400°C.

[0020] Optionally, the third in-situ heating process is an in-situ infrared heating process, and the process parameters of the third in-situ heating process also include: a pressure range of 1×10-10 millitorr~1×10 -8 mTorr; infrared energy density range is 10 W / cm2 to 30 W / cm2.

[0021] Optionally, the base includes a substrate and an electrode layer located on the surface of the substrate; the material of the electrode layer includes: one or a combination of titanium, tantalum, platinum, copper, tungsten, aluminum, titanium nitride, tantalum nitride and tungsten silicide.

[0022] Optionally, the first electromagnetic film is a single-layer structure or a stacked-layer structure, and the stacked-layer structure includes: a first lower electromagnetic film, a first middle electromagnetic film located on the surface of the first lower electromagnetic film, and a first upper electromagnetic film located on the surface of the first middle electromagnetic film.

[0023] Optionally, the first lower electromagnetic film, the first middle electromagnetic film and the first upper electromagnetic film are made of different materials.

[0024] Optionally, the second electromagnetic film is a single-layer structure or a stacked-layer structure, and the stacked-layer structure includes: a second lower electromagnetic film, a second middle electromagnetic film located on the surface of the second lower electromagnetic film, and a second upper electromagnetic film located on the surface of the second middle electromagnetic film.

[0025] Optionally, the second lower electromagnetic film, the second middle electromagnetic film and the second upper electromagnetic film are made of different materials.

[0026] Optionally, the material of the first electromagnetic film includes: cobalt platinum, and one or a combination of iron, cobalt, nickel, cobalt iron boron, cobalt iron, nickel iron and lanthanum strontium manganese oxide.

[0027] Optionally, the material of the tunnel film includes: one or a combination of magnesium oxide, aluminum oxide, silicon nitride, silicon oxynitride, hafnium dioxide and zirconium dioxide.

[0028] Optionally, the material of the second electromagnetic film includes: cobalt iron terbium, and one or a combination of iron, cobalt, nickel, cobalt iron boron, cobalt iron, nickel iron and lanthanum strontium manganese oxide.

[0029] Optionally, it also includes: after forming the second electromagnetic film, forming a mask layer on the second electromagnetic film, and the mask layer exposes a portion of the surface of the second electromagnetic film; using the mask layer as a mask, etching the second electromagnetic film, the tunnel film and the first electromagnetic film until the surface of the substrate is exposed, forming a first electromagnetic layer on the substrate, a tunnel layer located on the first electromagnetic layer, and a second electromagnetic layer located on the tunnel layer.

[0030] Optionally, the method further includes: after forming the first electromagnetic layer, the tunnel layer and the second electromagnetic layer, forming an interconnection structure in the mask layer, wherein the interconnection structure and the second electromagnetic layer are electrically interconnected, and the mask layer surface exposes the surface of the interconnection structure.

[0031] Optionally, the process of forming the first electromagnetic film includes a deposition process; the process of forming the second electromagnetic film includes a deposition process; and the process of forming the tunnel film includes a deposition process.

[0032] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0033] In the method for forming a semiconductor structure provided by the technical solution of the present invention, heat treatment is used to improve the lattice structure and interface state of the first electromagnetic film and the tunnel film to increase the tunnel resistance ratio of the subsequently formed magnetic tunnel junction, thereby improving the performance of the magnetic tunnel junction and enabling the MRAM to store more data. Since the first electromagnetic film and the tunnel film are heat-treated after forming the first electromagnetic film and the tunnel film and before forming the second electromagnetic film on the surface of the tunnel film, on the one hand, the heat treatment does not involve the second electromagnetic film. Therefore, it is possible to reduce the thermal diffusion between the second electromagnetic film material and the first electromagnetic film material and the tunnel film material caused by the heat treatment, and reduce the damage to the lattice structure and interface state of the improved first electromagnetic film and tunnel film caused by the heat diffusion, thereby facilitating the improvement of the lattice structure and interface state of the first electromagnetic film and the tunnel film. On the other hand, since the first electromagnetic film and the tunnel film are heat-treated using the first heating process before forming the second electromagnetic film, the heat loss caused by heat conduction during the heat treatment is reduced, thereby reducing the heat loss budget in the first heating process and lowering the heating temperature of the first heating process. Thus, the mutual diffusion between the first electromagnetic film material and the tunnel film material is reduced, thereby reducing the damage to the lattice structure and interface state of the improved first electromagnetic film and tunnel film caused by the mutual diffusion, which is conducive to improving the lattice structure and interface state of the first electromagnetic film and the tunnel film. Not only that, the electromagnetic film (second electromagnetic film) that needs to be processed by the first heating process is reduced, and the first heating process can also adjust the process parameters for the first electromagnetic film and the tunnel film, thereby improving the heating process accuracy, so that the lattice structure and interface state of the first electromagnetic film and the tunnel film are better improved, thereby improving the performance of the magnetic tunnel junction.

[0034] Furthermore, because the first heating process is an in-situ heating process, the heat treatment of the first electromagnetic film and the tunnel film is performed in a vacuum environment, thereby reducing oxidation of the substrate material, the first electromagnetic film material, and the tunnel film material, thereby improving the performance of the magnetic tunnel junction. Furthermore, due to the use of an in-situ heating process, during the formation of the first electromagnetic film, the tunnel film, and the second electromagnetic film, the heat treatment of the first electromagnetic film and the tunnel film can be performed without changing the workbench, thereby reducing the process complexity of the magnetic tunnel junction.

[0035] Furthermore, since the second heating process is used to heat treat the first electromagnetic film before forming the tunnel film, heat loss caused by heat conduction during the heat treatment is further reduced, thereby reducing the heat loss budget in the first and second heating processes and further lowering the heating temperatures of the first and second heating processes. This further reduces the interdiffusion between the first electromagnetic film material and the tunnel film material, thereby reducing the damage caused by this interdiffusion to the improved lattice structure and interface states of the first electromagnetic film and tunnel film, which is beneficial for improving the lattice structure and interface states of the first electromagnetic film and tunnel film, thereby improving the performance of the magnetic tunnel junction. Furthermore, the second heating process can adjust the process parameters specifically for the first electromagnetic film, and the subsequent first heating process can adjust the process parameters only for the tunnel film. This further increases the accuracy of the first and second heating processes for different materials, further improving the lattice structure and interface states of the first electromagnetic film and tunnel film, and further improving the performance of the magnetic tunnel junction.

[0036] Furthermore, since a third heating process is used to heat-treat the second electromagnetic film after forming the second electromagnetic film, the third heating process, on the one hand, targets only the second electromagnetic film, thereby reducing heat loss caused by heat conduction during the heat treatment, thereby reducing the heat loss budget in the third heating process and lowering the heating temperature of the third heating process. This reduces interdiffusion between the first electromagnetic film material, the tunnel film material, and the second electromagnetic film material, thereby reducing damage to the improved lattice structure and interface states of the first electromagnetic film, the tunnel film, and the second electromagnetic film materials caused by this interdiffusion, thereby facilitating improvements in the lattice structure and interface states of the first electromagnetic film, the tunnel film, and the second electromagnetic film materials. Furthermore, the third heating process can adjust process parameters specifically for the second electromagnetic film, thereby increasing the process accuracy of the heat treatment of the second electromagnetic film, facilitating better improvements in the lattice structure and interface states of the second electromagnetic film, and further enhancing the performance of the magnetic tunnel junction. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figures 1 to 2 The present invention is a structural schematic diagram of each step of a method for forming a semiconductor structure;

[0038] Figures 3 to 9 It is a schematic cross-sectional structural diagram of each step in the method for forming a semiconductor structure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] As described in the background art, the performance of magnetic tunnel junctions prepared by the prior art is relatively poor. The reasons for the poor performance of magnetic tunnel junctions are described in detail below with reference to the accompanying drawings.

[0040] Figures 1 to 2 The present invention is a structural schematic diagram of each step of a method for forming a semiconductor structure.

[0041] Please refer to Figure 1 , providing a substrate 10 having a first electromagnetic film 11, a tunnel film 12 located on the surface of the first electromagnetic film 11, and a second electromagnetic film 13 located on the surface of the tunnel film 12.

[0042] The first electromagnetic film 11 is used to form a first electromagnetic layer, the tunnel film 12 is used to form a tunnel layer, and the second electromagnetic film 13 is used to form a second electromagnetic layer. The first electromagnetic layer, the tunnel layer, and the second electromagnetic layer constitute a magnetic tunnel junction.

[0043] Please refer to Figure 2 , an annealing process is used to heat treat the first electromagnetic film 11, the tunnel film 12 and the second electromagnetic film 13.

[0044] Thus, the lattice structures and interface states of the first electromagnetic film 11 , the tunnel film 12 , and the second electromagnetic film 13 are improved through the heat treatment, so as to enhance the performance of the magnetic tunnel junction formed subsequently.

[0045] However, in the above method, since the annealing process is performed simultaneously on the first electromagnetic film 11, the tunnel film 12, and the second electromagnetic film 13, the first electromagnetic film 11, the tunnel film 12, and the second electromagnetic film 13 are heated simultaneously. Therefore, on the one hand, heat is conducted between the multiple material layers (the first electromagnetic film 11, the tunnel film 12, and the second electromagnetic film 13), increasing heat loss during the heat conduction process. To compensate for this heat loss, the annealing temperature needs to be increased. This increases the mutual diffusion between the first electromagnetic film 11, the tunnel film 12, and the second electromagnetic film 13 due to the influence of the heat treatment, thereby increasing the damage caused by this mutual diffusion to the lattice structure and interface states, which is not conducive to improving the performance of the magnetic tunnel junction. Furthermore, since the annealing process requires simultaneous heat treatment of multiple materials, each of which has different thermal conductivities, the annealing process is less targeted to each material and has low process precision, which is not conducive to improving the lattice structure and interface states of the first electromagnetic film 11, the tunnel film 12, and the second electromagnetic film 13, thereby further leading to poor performance of the magnetic tunnel junction.

[0046] In order to solve the above problems, the technical solution of the present invention provides a method for forming a semiconductor structure. After forming the first electromagnetic film and the tunnel film, and before forming the second electromagnetic film on the surface of the tunnel film, a first heating process is used to heat-treat the first electromagnetic film and the tunnel film. Thus, while improving the lattice structure and interface state of the magnetic tunnel junction, the mutual diffusion caused by the heat treatment is reduced and the accuracy of the heating process is improved, thereby improving the performance of the magnetic tunnel junction.

[0047] In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0048] Figures 3 to 9 It is a schematic cross-sectional structural diagram of each step in the method for forming a semiconductor structure according to an embodiment of the present invention.

[0049] Please refer to Figure 3 , providing a substrate 100.

[0050] In this embodiment, the base 100 includes a substrate 110 and an electrode layer 120 located on a surface of the substrate 100 .

[0051] The substrate 110 is made of semiconductor material.

[0052] In this embodiment, the substrate 110 is made of silicon. In other embodiments, the substrate may be made of silicon carbide, silicon germanium, a multinary semiconductor material composed of Group III-V elements, silicon-on-insulator (SOI), or germanium-on-insulator. The multinary semiconductor material composed of Group III-V elements may include InP, GaAs, GaP, InAs, InSb, InGaAs, or InGaAsP.

[0053] In another embodiment, the substrate further includes a device layer (not shown). The device layer may include a device structure, such as a PMOS transistor and an NMOS transistor. The device layer may further include an interconnect structure electrically connected to the device structure, and an insulating layer surrounding the device structure and the interconnect structure.

[0054] The material of the electrode layer 120 includes: one or a combination of titanium, tantalum, platinum, copper, tungsten, aluminum, titanium nitride, tantalum nitride and tungsten silicide.

[0055] In this embodiment, the material of the electrode layer 120 is tungsten.

[0056] Please refer to Figure 4 , a first electromagnetic film 200 is formed on the substrate 100.

[0057] The first electromagnetic film 200 provides material for subsequently forming a first electromagnetic layer.

[0058] The process of forming the first electromagnetic film 200 includes a deposition process or an epitaxial growth process.

[0059] In this embodiment, the process of forming the first electromagnetic film 200 includes a deposition process.

[0060] In this embodiment, the first electromagnetic film 200 is a stacked structure.

[0061] Specifically, the stacking structure of the first electromagnetic film 200 includes: a first lower electromagnetic film 210 located on the surface of the electrode layer 120 , a first middle electromagnetic film 220 located on the surface of the first lower electromagnetic film 210 , and a first upper electromagnetic film 230 located on the surface of the first middle electromagnetic film 220 .

[0062] In another embodiment, the first electromagnetic film is a single-layer structure.

[0063] The material of the first electromagnetic film 200 includes: cobalt platinum, and one or a combination of iron, cobalt, nickel, cobalt iron boron, cobalt iron, nickel iron and lanthanum strontium manganese oxide.

[0064] In this embodiment, the first lower electromagnetic film 210 , the first middle electromagnetic film 220 , and the first upper electromagnetic film 230 are made of different materials.

[0065] Specifically, in this embodiment, the material of the first lower electrode film 210 is cobalt platinum, the material of the first middle electromagnetic film 220 is cobalt iron boron, and the material of the first upper electromagnetic film 230 is cobalt iron.

[0066] Please refer to Figure 5 , a tunnel film 300 is formed on the surface of the first electromagnetic film 200 .

[0067] The tunnel film 300 provides materials for the subsequent formation of a tunnel layer.

[0068] The process of forming the tunnel film 300 includes a deposition process or an epitaxial growth process.

[0069] In this embodiment, the process of forming the tunnel film 300 includes a deposition process.

[0070] The material of the tunnel film 300 includes one or a combination of magnesium oxide, aluminum oxide, silicon nitride, silicon oxynitride, hafnium dioxide, and zirconium dioxide.

[0071] In this embodiment, the material of the tunnel film 300 is magnesium oxide.

[0072] Please refer to Figure 6, using a first heating process to heat-treat the first electromagnetic film 200 and the tunnel film 300.

[0073] The heat treatment is used to improve the lattice structure and interface state of the first electromagnetic film 200 and the tunnel film 300 to increase the tunnel resistance ratio of the subsequently formed magnetic tunnel junction, thereby improving the performance of the magnetic tunnel junction and enabling the MRAM to store more data.

[0074] Since the first electromagnetic film 200 and the tunnel film 300 are heat-treated after forming the first electromagnetic film 200 and the tunnel film 300 and before subsequently forming the second electromagnetic film, on the one hand, the heat treatment does not involve the second electromagnetic film. Therefore, it is possible to reduce the heat diffusion between the second electromagnetic film material and the first electromagnetic film 200 material and the tunnel film 300 material caused by the heat treatment, and reduce the damage caused by the heat diffusion to the lattice structure and interface state of the improved first electromagnetic film 200 and tunnel film 300, thereby improving the lattice structure and interface state of the first electromagnetic film 200 and the tunnel film 300. On the other hand, since the first electromagnetic film 200 and the tunnel film 300 are heat-treated by the first heating process before the second electromagnetic film is formed, the heat loss caused by heat conduction during the heat treatment is reduced, thereby reducing the heat loss budget in the first heating process and lowering the heating temperature of the first heating process. As a result, the mutual diffusion between the first electromagnetic film 200 material and the tunnel film 300 material is reduced, thereby reducing the damage caused by the mutual diffusion to the lattice structure and interface state of the improved first electromagnetic film 200 and tunnel film 300, which is beneficial to improving the lattice structure and interface state of the first electromagnetic film 200 and tunnel film 300.

[0075] Moreover, since the electromagnetic film (second electromagnetic film) that needs to be processed by the first heating process is reduced, the first heating process can also adjust the process parameters for the first electromagnetic film 200 and the tunnel film 300, thereby improving the accuracy of the heating process, so that the lattice structure and interface state of the first electromagnetic film 200 and the tunnel film 300 are better improved, thereby improving the performance of the magnetic tunnel junction.

[0076] In this embodiment, the first heating process includes a first in-situ heating process.

[0077] Because the first heating process is an in-situ heating process, the heat treatment of the first electromagnetic film 200 and the tunnel film 300 is performed in a vacuum environment, thereby reducing oxidation of the substrate 100 material, the first electromagnetic film 200 material, and the tunnel film 300 material, thereby improving the performance of the magnetic tunnel junction. Furthermore, due to the use of an in-situ heating process, during the formation of the first electromagnetic film 200, the tunnel film 300, and the second electromagnetic film, the first electromagnetic film 200 and the tunnel film 300 can be heat treated without changing the workbench, thereby reducing the process complexity of the magnetic tunnel junction.

[0078] In this embodiment, the process parameters of the first in-situ heating process include: a temperature range of 200°C to 350°C.

[0079] If the temperature is too high, the interdiffusion between the material of the first electromagnetic film 200 and the material of the tunnel film 300 will be exacerbated, which is not conducive to reducing the damage caused by the interdiffusion to the lattice structure and interface states of the improved first electromagnetic film 200 and tunnel film 300. If the temperature is too low, the lattice structure and interface states of the tunnel film 300 and the first electromagnetic film 200 cannot be effectively improved, which is not conducive to improving the performance of the magnetic tunnel junction. Therefore, selecting the temperature range can effectively improve the lattice structure and interface states of the tunnel film 300 and the first electromagnetic film 200 while reducing the interdiffusion between the material of the first electromagnetic film 200 and the material of the tunnel film 300.

[0080] The first in-situ heating process includes: an in-situ laser heating process or an in-situ infrared heating process.

[0081] In this embodiment, the first in-situ heating process is an in-situ infrared heating process.

[0082] In this embodiment, the process parameters of the first in-situ heating process also include: a pressure range of 1×10 -10 millitorr~1×10 -8 mTorr; infrared energy density range is 10 W / cm2 to 30 W / cm2.

[0083] It should be noted that the pressure range is 1×10 -10 millitorr~1×10 -8 Millitorr means that the first in-situ heating process is performed in a vacuum environment.

[0084] In another embodiment, before forming the tunnel film, a second heating process is used to heat-treat the first electromagnetic film.

[0085] Because the second heating process is used to heat treat the first electromagnetic film before forming the tunnel film, heat loss caused by heat conduction during the heat treatment is further reduced, thereby reducing the heat loss budget in the second heating process and the subsequent first heating process, and lowering the heating temperatures of the first and second heating processes. This further reduces the interdiffusion between the first electromagnetic film material and the tunnel film material, thereby reducing the damage caused by this interdiffusion to the improved lattice structure and interface states of the first electromagnetic film and tunnel film, which is beneficial for improving the lattice structure and interface states of the first electromagnetic film and tunnel film, thereby improving the performance of the magnetic tunnel junction. Furthermore, the process parameters of the second heating process can be adjusted specifically for the first electromagnetic film, while the process parameters of the subsequent first heating process can be adjusted only for the tunnel film. This further increases the accuracy of the first and second heating processes for different materials, further improving the lattice structure and interface states of the first electromagnetic film and tunnel film, and further improving the performance of the magnetic tunnel junction.

[0086] Specifically, in another embodiment, the heat treatment of the first electromagnetic film using the second heating process before forming the tunnel film includes: heat treatment of the first lower electrode film using the second heating process before forming the first middle electrode film; or heat treatment of the first lower electrode film and the first middle electrode film using the second heating process before forming the first upper electrode film; or heat treatment of the first lower electrode film, the first middle electrode film, and the first upper electromagnetic film after forming the first upper electrode film. This improves the flexibility of the heat treatment process for the first electromagnetic film.

[0087] In another embodiment, the second heating process includes a second in-situ heating process.

[0088] Because the second heating process is an in-situ heating process, the heat treatment of the first electromagnetic film is performed in a vacuum environment, thereby reducing oxidation of the substrate material and the first electromagnetic film material, thereby improving the performance of the magnetic tunnel junction. Furthermore, due to the use of an in-situ heating process, the first electromagnetic film can be heat treated without changing the workbench during the formation of the first electromagnetic film, tunnel film, and second electromagnetic film, thereby reducing the process complexity of the magnetic tunnel junction.

[0089] In another embodiment, the second in-situ heating process includes: an in-situ laser heating process or an in-situ infrared heating process. The process parameters of the second in-situ heating process include: a temperature range of 250°C to 400°C. When the second in-situ heating process is an in-situ infrared heating process, the process parameters of the second in-situ heating process also include: a pressure range of 1×10 -10 millitorr~1×10-8 mTorr; infrared energy density range is 10 W / cm2 to 30 W / cm2.

[0090] It should be noted that the pressure range is 1×10 -10 millitorr~1×10 -8 Millitorr means that the second in-situ heating process is performed in a vacuum environment.

[0091] Please refer to Figure 7 After the first electromagnetic film 200 and the tunnel film 300 are heat-treated, a second electromagnetic film 400 is formed on the surface of the tunnel film 300 .

[0092] The second electromagnetic film 400 provides material for subsequently forming a second electromagnetic layer.

[0093] The process of forming the second electromagnetic film 400 includes a deposition process or an epitaxial growth process.

[0094] In this embodiment, the process of forming the second electromagnetic film 400 includes a deposition process.

[0095] In this embodiment, the second electromagnetic film 400 is a stacked structure.

[0096] Specifically, the stacking structure of the second electromagnetic film 400 includes: a second lower electromagnetic film 410 located on the surface of the tunnel film 300 , a second middle electromagnetic film 420 located on the surface of the second lower electromagnetic film 410 , and a second upper electromagnetic film 430 located on the surface of the second middle electromagnetic film 420 .

[0097] In another embodiment, the second electromagnetic film is a single-layer structure.

[0098] The material of the second electromagnetic film 400 includes: cobalt iron terbium, and one or a combination of iron, cobalt, nickel, cobalt iron boron, cobalt iron, nickel iron and lanthanum strontium manganese oxide.

[0099] In this embodiment, the second lower electromagnetic film 410 , the second middle electromagnetic film 420 , and the second upper electromagnetic film 430 are made of different materials.

[0100] Specifically, in this embodiment, the material of the second lower electromagnetic film 410 is cobalt iron, the material of the second middle electromagnetic film 420 is cobalt iron boron, and the material of the second upper electromagnetic film 430 is cobalt iron terbium.

[0101] Please refer to Figure 8 After forming the second electromagnetic film 400 , a third heating process is used to heat-treat the second electromagnetic film 400 .

[0102] After forming the second electromagnetic film 400, a third heating process is used to heat-treat the second electromagnetic film 400. The third heating process targets only the second electromagnetic film 400, thereby reducing heat loss due to heat conduction during the heat treatment process. This reduces the heat loss budget in the third heating process and lowers the heating temperature of the third heating process. This reduces interdiffusion between the materials of the first electromagnetic film 200, the tunnel film 300, and the second electromagnetic film 400, thereby reducing damage to the improved lattice structure and interface states of the first electromagnetic film 200, the tunnel film 300, and the second electromagnetic film 400. This helps improve the lattice structure and interface states of the first electromagnetic film 200, the tunnel film 300, and the second electromagnetic film 400. Furthermore, the third heating process allows process parameters to be adjusted specifically for the second electromagnetic film 400, thereby increasing the process accuracy of the heat treatment of the second electromagnetic film 400, further improving the lattice structure and interface states of the second electromagnetic film 400 and further enhancing the performance of the magnetic tunnel junction.

[0103] In another embodiment, the second electromagnetic film 400 is not subjected to heat treatment.

[0104] In this embodiment, the third heating process includes a third in-situ heating process.

[0105] Because the third heating process is an in-situ heating process, the heat treatment of the second electromagnetic film 400 is performed in a vacuum environment, thereby reducing oxidation of the substrate 100 material, the first electromagnetic film 200 material, the tunnel film 300 material, and the second electromagnetic film 400 material, thereby improving the performance of the magnetic tunnel junction. Furthermore, due to the use of an in-situ heating process, the second electromagnetic film 400 can be heat treated during the formation of the first electromagnetic film 200, the tunnel film 300, and the second electromagnetic film without changing the workbench, thereby reducing the process complexity of the magnetic tunnel junction.

[0106] In this embodiment, the process parameters of the third in-situ heating process include: a temperature range of 200°C to 400°C.

[0107] If the temperature is too high, the interdiffusion between the materials of the first electromagnetic film 200, the tunnel film 300, and the second electromagnetic film 400 will be exacerbated, which is not conducive to reducing the damage caused by this interdiffusion to the lattice structure and interface states of the improved first electromagnetic film 200, tunnel film 300, and second electromagnetic film 400. If the temperature is too low, the lattice structure and interface states of the second electromagnetic film 400 cannot be effectively improved, which is not conducive to improving the performance of the magnetic tunnel junction. Therefore, selecting this temperature range can effectively improve the lattice structure and interface states of the second electromagnetic film 400 while reducing the interdiffusion between the materials of the first electromagnetic film 200, tunnel film 300, and second electromagnetic film 400.

[0108] The third in-situ heating process includes: an in-situ laser heating process or an in-situ infrared heating process.

[0109] In this embodiment, the third in-situ heating process is an in-situ infrared heating process.

[0110] In this embodiment, the process parameters of the third in-situ heating process also include: a pressure range of 1×10 -10 millitorr~1×10 -8 mTorr; infrared energy density range is 10 W / cm2 to 30 W / cm2.

[0111] It should be noted that the pressure range is 1×10 -10 millitorr~1×10 -8 Millitorr means that the first in-situ heating process is performed in a vacuum environment.

[0112] Please refer to Figure 9 After forming the second electromagnetic film 400, a mask layer 500 is formed on the second electromagnetic film 400, and the mask layer 500 exposes a portion of the surface of the second electromagnetic film 400; using the mask layer 500 as a mask, the second electromagnetic film 400, the tunnel film 300 and the first electromagnetic film 200 are etched until the surface of the substrate 100 is exposed, and a first electromagnetic layer 240, a tunnel layer 310 located on the first electromagnetic layer 240, and a second electromagnetic layer 440 located on the tunnel layer 310 are formed on the substrate 100.

[0113] The first electromagnetic layer 240 , the tunnel layer 310 , and the second electromagnetic layer 440 form a magnetic tunnel junction 600 .

[0114] The tunnel layer 310 serves as a tunneling barrier between the first electromagnetic layer 240 and the second electromagnetic layer 440 .

[0115] Data “0” or data “1” can be stored by the first electromagnetic layer 240 and the second electromagnetic layer 440 having the same or different magnetization directions.

[0116] In this embodiment, the first electromagnetic layer 240 includes: a first lower electromagnetic layer 211 located on the surface of the electrode layer 120 , a first middle electromagnetic layer 221 located on the surface of the first lower electromagnetic layer 211 , and a first upper electromagnetic layer 231 located on the surface of the first middle electromagnetic layer 221 .

[0117] In this embodiment, the second electromagnetic layer 440 includes: a second lower electromagnetic layer 411 located on the surface of the tunnel layer 310 , a second middle electromagnetic layer 421 located on the surface of the second lower electromagnetic layer 411 , and a second upper electromagnetic layer 431 located on the surface of the second middle electromagnetic layer 421 .

[0118] In this embodiment, the mask layer 500 is a single-layer structure; in other embodiments, the mask layer 500 may also be a stacked structure.

[0119] In this embodiment, after forming the first electromagnetic layer 240, the tunnel layer 310 and the second electromagnetic layer 440, an interconnection structure (not shown) is formed in the mask layer 500. The interconnection structure (not shown) and the second electromagnetic layer 440 are electrically interconnected, and the surface of the mask layer 500 exposes the surface of the interconnection structure.

[0120] Therefore, the magnetic tunnel junction 600 can be electrically interconnected with other devices through the interconnection structure.

[0121] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A method for forming a semiconductor structure, characterized in that: include: providing a substrate; forming a first electromagnetic film on the substrate; Using a second heating process to heat-treat the first electromagnetic film, and in the step of using the second heating process, adjusting process parameters for the first electromagnetic film; After heat-treating the first electromagnetic film, a tunnel film is formed on the surface of the first electromagnetic film; Using a first heating process to heat-treat the first electromagnetic film and the tunnel film, wherein in the step of using the first heating process, process parameters are adjusted for the tunnel film to reduce mutual diffusion between the first electromagnetic film material and the tunnel film material; After heat treating the first electromagnetic film and the tunnel film, forming a second electromagnetic film on the surface of the tunnel film; The second electromagnetic film is heat-treated using a third heating process. During the third heating process, process parameters are adjusted for the second electromagnetic film to reduce mutual diffusion among the first electromagnetic film material, the tunnel film material, and the second electromagnetic film material.

2. The method for forming a semiconductor structure according to claim 1, wherein: The first heating process includes a first in-situ heating process.

3. The method for forming a semiconductor structure according to claim 2, wherein: The first in-situ heating process includes one of an in-situ laser heating process or an in-situ infrared heating process.

4. The method for forming a semiconductor structure according to claim 2, wherein: The process parameters of the first in-situ heating process include: a temperature range of 200°C to 350°C.

5. The method for forming a semiconductor structure according to claim 3, wherein: The first in-situ heating process is an in-situ infrared heating process, and the process parameters of the first in-situ heating process also include: a pressure range of 1×10 -10 millitorr~1×10 -8 mTorr; infrared energy density range is 10 W / cm2 ~ 30 W / cm2.

6. The method for forming a semiconductor structure according to claim 1, wherein: The second heating process includes a second in-situ heating process.

7. The method for forming a semiconductor structure according to claim 6, wherein: The second in-situ heating process includes one of an in-situ laser heating process and an in-situ infrared heating process.

8. The method for forming a semiconductor structure according to claim 6, wherein: The process parameters of the second in-situ heating process include: a temperature range of 250°C to 400°C.

9. The method for forming a semiconductor structure according to claim 8, wherein: The second in-situ heating process is an in-situ infrared heating process. The process parameters of the second in-situ heating process also include: a pressure range of 1×10 -10 millitorr~1×10 -8 mTorr; infrared energy density range is 10 W / cm2 ~ 30 W / cm2.

10. The method for forming a semiconductor structure according to claim 1, wherein: The third heating process includes a third in-situ heating process.

11. The method for forming a semiconductor structure according to claim 10, wherein: The third in-situ heating process includes one of an in-situ laser heating process and an in-situ infrared heating process.

12. The method for forming a semiconductor structure according to claim 10, wherein: The process parameters of the third in-situ heating process include: a temperature range of 250°C to 400°C.

13. The method for forming a semiconductor structure according to claim 12, wherein: The third in-situ heating process is an in-situ infrared heating process, and the process parameters of the third in-situ heating process also include: a pressure range of 1×10 -10 millitorr~1×10 -8 mTorr; infrared energy density range is 10 W / cm2 ~ 30 W / cm2.

14. The method for forming a semiconductor structure according to claim 1, wherein: The base includes a substrate and an electrode layer located on the surface of the substrate; the material of the electrode layer includes: one or a combination of titanium, tantalum, platinum, copper, tungsten, aluminum, titanium nitride, tantalum nitride and tungsten silicide.

15. The method for forming a semiconductor structure according to claim 1, wherein: The first electromagnetic film is a single-layer structure or a stacked-layer structure, and the stacked-layer structure includes: a first lower electromagnetic film, a first middle electromagnetic film located on the surface of the first lower electromagnetic film, and a first upper electromagnetic film located on the surface of the first middle electromagnetic film.

16. The method for forming a semiconductor structure according to claim 15, wherein: The first lower electromagnetic film, the first middle electromagnetic film and the first upper electromagnetic film are made of different materials.

17. The method for forming a semiconductor structure according to claim 1, wherein: The second electromagnetic film is a single-layer structure or a stacked-layer structure, and the stacked-layer structure includes: a second lower electromagnetic film, a second middle electromagnetic film located on the surface of the second lower electromagnetic film, and a second upper electromagnetic film located on the surface of the second middle electromagnetic film.

18. The method for forming a semiconductor structure according to claim 17, wherein: The second lower electromagnetic film, the second middle electromagnetic film and the second upper electromagnetic film are made of different materials.

19. The method for forming a semiconductor structure according to claim 1, wherein: The material of the first electromagnetic film includes: cobalt platinum, and one or a combination of iron, cobalt, nickel, cobalt iron boron, cobalt iron, nickel iron and lanthanum strontium manganese oxide.

20. The method for forming a semiconductor structure according to claim 1, wherein: The material of the tunnel film includes: one or a combination of magnesium oxide, aluminum oxide, silicon nitride, silicon oxynitride, hafnium dioxide and zirconium dioxide.

21. The method for forming a semiconductor structure according to claim 1, wherein: The material of the second electromagnetic film includes: cobalt iron terbium, and one or a combination of iron, cobalt, nickel, cobalt iron boron, cobalt iron, nickel iron and lanthanum strontium manganese oxide.

22. The method for forming a semiconductor structure according to claim 1, wherein: Also includes: After forming the second electromagnetic film, forming a mask layer on the second electromagnetic film, wherein the mask layer exposes a portion of the surface of the second electromagnetic film; Using the mask layer as a mask, the second electromagnetic film, the tunnel film and the first electromagnetic film are etched until the surface of the substrate is exposed, thereby forming a first electromagnetic layer, a tunnel layer on the first electromagnetic layer, and a second electromagnetic layer on the tunnel layer on the substrate.

23. The method for forming a semiconductor structure according to claim 22, wherein: Also includes: After forming the first electromagnetic layer, the tunnel layer and the second electromagnetic layer, an interconnection structure is formed in the mask layer. The interconnection structure and the second electromagnetic layer are electrically interconnected, and the mask layer surface exposes the surface of the interconnection structure.

24. The method for forming a semiconductor structure according to claim 1, wherein: The process of forming the first electromagnetic film includes a deposition process; the process of forming the second electromagnetic film includes a deposition process; and the process of forming the tunnel film includes a deposition process.

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