Preparation method of magnetic storage unit

Abstract

The invention provides a preparation method of a magnetic storage unit, and the method comprises the steps: providing a substrate which comprises a magnetic storage unit bottom electrode; preparing a magnetic tunnel junction lamination layer on the bottom electrode, and obtaining more than one actual parameter of the magnetic tunnel junction lamination layer; comparing the actual parameter with a corresponding first preset parameter, and determining a comparison result; determining process parameters of a reference resistor corresponding to the magnetic tunnel junction lamination according to the comparison result; and forming the reference resistor according to the determined process parameters. According to the preparation method of the magnetic storage unit, the process parameters of the reference resistor needing to be prepared can be determined through the actual parameters after the magnetic tunnel lamination is prepared, so that the resistance value of the reference resistor is effectively controlled, and a sufficient read-out window is provided for the magnetic tunnel junction unit.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic storage, and in particular, to a method for fabricating a magnetic storage unit. Background Art

[0002] In the manufacture of new storage chips, storage units are integrated in the CMOS back-end process. Through bottom interconnection and top interconnection, electrical interconnection between the storage units and CMOS devices is achieved, thereby forming bits. A magnetic random access memory chip includes an array region and a logic region. The magnetic tunnel junction array is integrated in the metal wires of the CMOS back-end process. The array consists of several rows of bits, and each row consists of several columns of bits.

[0003] Due to its own device characteristics (tunnel magnetoresistance effect less than 200%), the magnetic random access memory chip has a small read window, so it poses high requirements on the process preparation itself. Usually, a multi-stage series silicon resistor scheme is adopted for the read reference of the magnetic random access memory chip. The problem with this scheme is that when the silicon resistor cannot be adjusted or the adjustment range of the silicon resistor is too large, if the magnetic tunnel junction device has a resistance offset due to process influence, it will cause the read window of the chip to shrink, easily resulting in read soft errors and reducing the yield. In an ideal situation, the reference resistor is in the middle of the high and low resistance states (Rp / Rap) of the magnetic tunnel junction, and there is a good bit read window; when the resistance of the magnetic tunnel junction drifts due to processing technology reasons, it will inevitably cause the read window of one of the high and low resistance states of the bit to shrink, and there is a risk of bit read soft errors. Summary of the Invention

[0004] The method for fabricating a magnetic storage unit provided by the present invention can determine the process parameters of the reference resistor to be fabricated according to the actual parameters after the magnetic tunnel stack is fabricated, thereby effectively controlling the resistance value of the reference resistor and providing a sufficient read window for the magnetic tunnel junction unit.

[0005] The present invention provides a method for fabricating a magnetic storage unit, the method comprising:

[0006] providing a substrate, the substrate including a bottom electrode of the magnetic storage unit;

[0007] fabricating a magnetic tunnel junction stack on the bottom electrode and obtaining one or more actual parameters of the magnetic tunnel junction stack;

[0008] comparing the actual parameters with corresponding first preset parameters to determine a comparison result;

[0009] determining process parameters of a reference resistor corresponding to the magnetic tunnel junction stack according to the comparison result;

[0010] forming the reference resistor according to the determined process parameters.

[0011] Optionally, obtaining one or more actual parameters of the magnetic tunnel junction stack includes:

[0012] Obtaining the actual thickness parameter of the magnetic tunnel junction stack and / or the actual planar size parameter of the magnetic tunnel junction stack.

[0013] Optionally, the process parameters for determining the reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result include:

[0014] When the difference between the actual thickness parameter of the magnetic tunnel junction stack and the first preset thickness parameter in the first preset parameters is greater than the first preset threshold, adjust the second preset thickness parameter of the reference resistance so that the difference between the read window of the high resistance state and the read window of the low resistance state of the magnetic tunnel junction is not greater than the third preset threshold.

[0015] Optionally, the process parameters for determining the reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result include:

[0016] When the difference between the actual planar size parameter of the magnetic tunnel junction stack and the first preset planar size parameter in the first preset parameters is greater than the second preset threshold, adjust the second preset planar size parameter of the reference resistance so that the difference between the read window of the high resistance state and the read window of the low resistance state of the magnetic tunnel junction is not greater than the third preset threshold.

[0017] Optionally, the process parameters for determining the reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result include:

[0018] When the difference between the actual thickness parameter of the magnetic tunnel junction stack and the first preset thickness parameter in the first preset parameters is greater than the first preset threshold, adjust the second preset planar size parameter of the reference resistance so that the difference between the read window of the high resistance state and the read window of the low resistance state of the magnetic tunnel junction is not greater than the third preset threshold.

[0019] Optionally, the process parameters for determining the reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result include:

[0020] When the difference between the actual planar size parameter of the magnetic tunnel junction stack and the first preset planar size parameter in the first preset parameters is greater than the second preset threshold, adjust the second preset thickness parameter of the reference resistance so that the difference between the read window of the high resistance state and the read window of the low resistance state of the magnetic tunnel junction is not greater than the third preset threshold.

[0021] Optionally, the process parameters for determining the reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result include:

[0022] Obtain the difference between the actual thickness parameter and the first preset thickness parameter in the first preset parameter;

[0023] Calculate the ratio of the difference to the first preset thickness parameter;

[0024] Multiply the cross-sectional area corresponding to the second preset thickness parameter by the ratio to obtain the cross-sectional area that needs to be increased or decreased;

[0025] Obtain the adjusted cross-sectional area based on the cross-sectional area corresponding to the second preset thickness parameter and the cross-sectional area that needs to be increased or decreased;

[0026] Determine the adjusted second preset thickness parameter or the second preset plane size parameter based on the adjusted cross-sectional area.

[0027] Optionally, the process parameters for determining the reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result include:

[0028] Obtain the difference between the actual plane size parameter and the first preset plane size parameter in the first preset parameter;

[0029] Calculate the ratio of the difference to the first preset plane size parameter;

[0030] Multiply the cross-sectional area corresponding to the second preset plane size parameter by the ratio to obtain the cross-sectional area that needs to be increased or decreased;

[0031] Obtain the adjusted cross-sectional area based on the cross-sectional area corresponding to the second preset plane size parameter and the cross-sectional area that needs to be increased or decreased;

[0032] Determine the adjusted second preset plane size parameter or the adjusted second preset thickness parameter based on the adjusted cross-sectional area.

[0033] Optionally, the process parameters for determining the reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result include:

[0034] When the difference between the actual thickness parameter of the magnetic tunnel junction stack and the first preset thickness parameter is not greater than the first preset threshold, and the difference between the actual plane size parameter of the magnetic tunnel junction stack and the first preset plane size parameter is not greater than the second preset threshold; determine the second preset thickness parameter and the second preset plane size parameter of the reference resistance as the process parameters of the reference resistance corresponding to the magnetic tunnel junction.

[0035] Optionally, the forming of the reference resistance according to the determined process parameters includes:

[0036] Form a reference resistance thin film on the substrate;

[0037] Patterning the reference resistor film to form a reference resistor; wherein, both ends of the reference resistor in the length direction are electrically connected to a reference circuit.

[0038] In the technical solution provided by the present invention, the magnetic tunnel junction stack and the reference resistor are prepared separately. During the preparation of the magnetic tunnel junction stack, one or more actual parameters of the magnetic tunnel junction stack are obtained. During the preparation of the reference resistor, according to the actual parameters of the magnetic tunnel junction stack, the process parameters of the reference resistor are adjusted, so that the reference resistor can have a suitable read window for the magnetic tunnel junction stack in both high and low resistance states, reducing the risk of soft read error of the storage bit. Description of the Drawings

[0039] Figure 1 It is a flowchart of a method for preparing a magnetic storage unit according to an embodiment of the present invention;

[0040] Figure 2 It is a flowchart for adjustment when the thickness deviates in a method for preparing a magnetic storage unit according to an embodiment of the present invention;

[0041] Figure 3 It is a flowchart for adjustment when the planar dimension deviates in a method for preparing a magnetic storage unit according to an embodiment of the present invention;

[0042] Figure 4 It is a flowchart for forming a reference resistor in a method for preparing a magnetic storage unit according to an embodiment of the present invention. Detailed Embodiments

[0043] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0044] An embodiment of the present invention provides a method for preparing a magnetic storage unit, as Figure 1 shown, the method includes:

[0045] Step 100, providing a substrate, where the substrate includes a bottom electrode of the magnetic storage unit;

[0046] In some embodiments, the substrate includes film layers prepared by front-end processing techniques before the preparation of the storage unit, for example, the bottom electrode and the bottom through hole, etc.

[0047] Step 200, preparing a magnetic tunnel junction stack on the bottom electrode and obtaining one or more actual parameters of the magnetic tunnel junction stack;

[0048] In some embodiments, the magnetic tunnel junction stack includes at least a reference layer, a barrier layer, and a free layer. During the preparation process, it includes the formation of the magnetic tunnel junction stack and the patterning process of the magnetic tunnel junction stack. When obtaining the actual parameters of the magnetic tunnel junction stack, it is necessary to obtain the parameters that affect the resistance value of the magnetic tunnel junction stack, such as the film thickness, film width, and film length.

[0049] Step 300, compare the actual parameters with the corresponding first preset parameters to determine the comparison result;

[0050] In some embodiments, the first preset parameter refers to the expected parameter set before preparing the magnetic tunnel junction stack. Comparing the actual parameter with the first preset parameter can determine which parameter has a deviation during the preparation of the magnetic tunnel junction.

[0051] Step 400, determine the process parameters of the reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result;

[0052] In some embodiments, when there is a deviation between the actual parameter of the magnetic tunnel junction stack and the first preset parameter, it will cause the resistance value of the magnetic tunnel junction stack to be different from the preset resistance value. At this time, it is necessary to synchronously adjust the reference resistance so that the magnetic tunnel junction stack has a reasonable read range whether in the high-resistance state or the low-resistance state. Therefore, the process parameters of the reference resistance are adjusted in this step.

[0053] Step 500, form the reference resistance according to the determined process parameters.

[0054] In some embodiments, since the process parameters of the reference resistance are adjusted according to the actual parameters of the magnetic tunnel junction stack, it can ensure that the magnetic tunnel junction stack has a reasonable read range whether in the high-resistance state or the low-resistance state.

[0055] In the technical solution provided by the embodiments of the present invention, the magnetic tunnel junction stack and the reference resistance are prepared separately. During the preparation of the magnetic tunnel junction stack, the actual parameters of the magnetic tunnel junction stack are obtained. During the preparation of the reference resistance, the process parameters of the reference resistance are adjusted according to the actual parameters of the magnetic tunnel junction stack, so that the reference resistance can have a suitable read window for the magnetic tunnel junction stack in both high and low resistance states, reducing the risk of soft read error of the storage bit.

[0056] As an alternative implementation, in step 200, obtaining one or more actual parameters of the magnetic tunnel junction stack includes:

[0057] Obtain the actual thickness parameter of the magnetic tunnel junction stack and / or the actual planar dimension parameter of the magnetic tunnel junction stack.

[0058] In some embodiments, since the resistance value of the magnetic tunnel junction stack has a direct relationship with the resistivity, resistance thickness, resistance length, and resistance width, where the resistivity is a unique property of the material and does not change, and the resistance length and resistance width are the planar dimension parameters. Therefore, the actual thickness parameter and the actual planar dimension parameter can be obtained to determine the resistance value of the magnetic tunnel junction stack. The planar dimension parameters include the length of the magnetic tunnel junction and the width of the magnetic tunnel junction.

[0059] As an alternative implementation, in step 400, the process parameters for determining the reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result include:

[0060] When the difference between the actual thickness parameter of the magnetic tunnel junction stack and the first preset thickness parameter in the first preset parameters is greater than the first preset threshold, the second preset thickness parameter of the reference resistance is adjusted so that the difference between the read window of the high-resistance state and the read window of the low-resistance state of the magnetic tunnel junction is not greater than the third preset threshold.

[0061] In some embodiments, the first preset threshold can be determined based on empirical values. When the difference between the actual thickness parameter of the magnetic tunnel junction stack and the first preset thickness parameter in the first preset parameters is not greater than the first preset threshold, the reference resistance is prepared using the second preset thickness parameter, and the magnetic tunnel junction stack still has a good read window. The second preset thickness parameter is the thickness parameter of the reference resistance determined in advance based on the first preset thickness parameter. When the difference between the actual thickness parameter of the magnetic tunnel junction stack and the first preset thickness parameter in the first preset parameters is greater than the first preset threshold, the resistance value of the magnetic tunnel junction stack is quite different from the pre-expected resistance value. At this time, if the original second preset thickness parameter is still used, it will result in too small a read window for one of the high-resistance state and the low-resistance state of the magnetic tunnel junction. Therefore, it is necessary to adjust the second preset thickness parameter to change the resistance value of the reference resistance and ensure the read window of the magnetic tunnel junction.

[0062] As an alternative implementation, in step 400, the process parameters for determining the reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result include:

[0063] When the difference between the actual planar dimension parameter of the magnetic tunnel junction stack and the first preset planar dimension parameter in the first preset parameters is greater than the second preset threshold, the second preset planar dimension parameter of the reference resistance is adjusted so that the difference between the read window of the high-resistance state and the read window of the low-resistance state of the magnetic tunnel junction is not greater than the third preset threshold.

[0064] In some embodiments, since the change in the planar dimension also affects the resistance of the magnetic tunnel junction stack, in this embodiment, the actual planar dimension is judged. The second preset threshold can be determined based on empirical values, for example. When the difference between the actual planar dimension parameter of the magnetic tunnel junction stack and the first preset planar dimension parameter in the first preset parameters is not greater than the second preset threshold, the second preset planar dimension parameter is used to prepare the reference resistance, and the magnetic tunnel junction stack still has a good read window. The second preset planar dimension parameter is the planar dimension parameter of the reference resistance determined in advance based on the first preset planar dimension parameter. When the difference between the actual planar dimension parameter of the magnetic tunnel junction stack and the first preset planar dimension parameter in the first preset parameters is greater than the second preset threshold, the resistance value of the magnetic tunnel junction stack is quite different from the pre-expected resistance value. At this time, if the original second preset planar dimension parameter is still used, it will result in too small a read window for either the high-resistance state or the low-resistance state of the magnetic tunnel junction. Therefore, it is necessary to adjust the second preset planar dimension parameter to change the resistance value of the reference resistance and ensure the read window of the magnetic tunnel junction.

[0065] As an alternative embodiment, in step 400, the determining the process parameters of the reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result includes:

[0066] When the difference between the actual thickness parameter of the magnetic tunnel junction stack and the first preset thickness parameter in the first preset parameters is greater than the first preset threshold, the second preset planar dimension parameter of the reference resistance is adjusted so that the difference between the read window of the high-resistance state and the read window of the low-resistance state of the magnetic tunnel junction is not greater than the third preset threshold.

[0067] In some embodiments, since the resistance value of the reference resistance is determined by the resistance thickness parameter and the resistance planar dimension parameter, when the deviation of the actual thickness parameter of the magnetic tunnel junction stack is large, the resistance value of the reference resistance can also be adjusted by adjusting the second preset planar dimension parameter of the reference resistance.

[0068] As an alternative embodiment, in step 400, the determining the process parameters of the reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result includes:

[0069] When the difference between the actual planar dimension parameter of the magnetic tunnel junction stack and the first preset planar dimension parameter in the first preset parameters is greater than the second preset threshold, the second preset thickness parameter of the reference resistance is adjusted so that the difference between the read window of the high-resistance state and the read window of the low-resistance state of the magnetic tunnel junction is not greater than the third preset threshold.

[0070] In some embodiments, since the resistance value of the reference resistor is determined by the resistor thickness parameter and the resistor planar size parameter, when the deviation of the actual planar size parameter of the magnetic tunnel junction stack is relatively large, the resistance value of the reference resistor can also be adjusted by adjusting the second preset thickness parameter of the reference resistor.

[0071] As an alternative implementation, as Figure 2 shown, in step 400, the determining the process parameters of the reference resistor corresponding to the magnetic tunnel junction stack according to the comparison result includes:

[0072] Step 411, obtaining the difference between the actual thickness parameter and the first preset thickness parameter in the first preset parameters;

[0073] In some embodiments, for the magnetic tunnel junction stack, its resistance value is proportional to the film thickness and inversely proportional to the occupied planar area. Therefore, in this embodiment, for the case where the thickness exceeds the expectation, during the adjustment process, first, the difference between the actual thickness parameter and the first preset thickness parameter is obtained.

[0074] Step 412, calculating the ratio of the difference to the first preset thickness parameter;

[0075] In some embodiments, since during the adjustment of the resistance value of the reference resistor, it is necessary to adjust the deviation between the resistance value of the reference resistor and the resistance value of the magnetic tunnel junction stack in the same proportion, the corresponding ratio needs to be obtained.

[0076] Step 413, multiplying the cross-sectional area corresponding to the second preset thickness parameter by the ratio to obtain the cross-sectional area that needs to be increased or decreased;

[0077] In some embodiments, for the reference resistor, since the current flow direction is parallel to the length direction, and the length direction of the reference resistor is usually a fixed value and cannot be adjusted. Therefore, the change of the reference resistor is only related to the cross-sectional area enclosed by the thickness and the width. To adjust the resistance value in the same proportion, it is necessary to determine the cross-sectional area that needs to be increased or decreased according to the ratio. It should be noted that since the resistance value of the reference resistor is inversely proportional to the cross-sectional area, when the thickness of the magnetic tunnel junction stack is too thick, the cross-sectional area should be reduced, and when the thickness of the magnetic tunnel junction stack is too thin, the cross-sectional area should be increased.

[0078] Step 414, obtaining the adjusted cross-sectional area according to the cross-sectional area corresponding to the second preset thickness parameter and the cross-sectional area that needs to be increased or decreased;

[0079] In some embodiments, after adding the cross-sectional area that needs to be increased or subtracting the cross-sectional area that needs to be decreased from the cross-sectional area corresponding to the second preset thickness parameter, the adjusted cross-sectional area can be determined.

[0080] Step 415: Determine the adjusted second preset thickness parameter or the second preset planar dimension parameter according to the adjusted cross-sectional area.

[0081] In some embodiments, after determining the adjusted cross-sectional area, the second preset thickness parameter may be kept unchanged and the second preset planar dimension parameter, i.e., the second preset width parameter, may be changed, or the second preset width parameter may be kept unchanged and the second preset thickness parameter may be changed.

[0082] As an alternative implementation, as Figure 3 shown, in step 400, the process parameters for determining the reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result include:

[0083] Step 421: Obtain the difference between the actual planar dimension parameter and the first preset planar dimension parameter in the first preset parameters;

[0084] Step 422: Calculate the ratio of the difference to the first preset planar dimension parameter;

[0085] Step 423: Multiply the cross-sectional area corresponding to the second preset planar dimension parameter by the ratio to obtain the cross-sectional area that needs to be increased or decreased;

[0086] Step 424: Obtain the adjusted cross-sectional area according to the cross-sectional area corresponding to the second preset planar dimension parameter and the cross-sectional area that needs to be increased or decreased;

[0087] Step 425: Determine the adjusted second preset planar dimension parameter or the adjusted second preset thickness parameter according to the adjusted cross-sectional area.

[0088] The difference between this embodiment and the Figure 2 corresponding embodiment is that this embodiment adjusts the second preset thickness parameter or the second preset width parameter of the reference resistance for the case where the planar dimension of the magnetic tunnel junction stack deviates.

[0089] As an alternative implementation, in step 400, the process parameters for determining the reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result include:

[0090] When the difference between the actual thickness parameter of the magnetic tunnel junction stack and the first preset thickness parameter is not greater than the first preset threshold, and the difference between the actual planar dimension parameter of the magnetic tunnel junction stack and the first preset planar dimension parameter is not greater than the second preset threshold, determine the second preset thickness parameter and the second preset planar dimension parameter of the reference resistance as the process parameters for the reference resistance corresponding to the magnetic tunnel junction.

[0091] In some embodiments, when the deviation of the actual thickness parameter of the magnetic tunnel junction stack is within the allowable range, maintaining the second preset thickness parameter and the second preset planar dimension parameter can still ensure that the magnetic tunnel junction stack has a good read window.

[0092] As an alternative implementation, as Figure 4 shown, in step 500, forming the reference resistor according to the determined process parameters includes:

[0093] Step 510, forming a reference resistor thin film on a substrate;

[0094] Step 520, patterning the reference resistor thin film to form a reference resistor; wherein, both ends of the reference resistor in the length direction are electrically connected to a reference circuit.

[0095] In some embodiments, the bottom through hole and the top through hole in this embodiment are respectively arranged at both ends in the length direction of the reference resistor, so that the current direction is parallel to the length direction. Furthermore, adjusting the resistance value of the reference resistor only requires adjusting the thickness and width.

[0096] Those of ordinary skill in the art can understand that implementing all or part of the processes in the above method embodiments can be completed by instructing relevant hardware through a computer program. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above method embodiments. Among them, the storage medium can be a magnetic disk, an optical disc, a read-only memory (ROM), or a random access memory (RAM), etc.

[0097] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for preparing a magnetic storage unit, characterized in that, The method includes: providing a substrate, where the substrate includes a bottom electrode of a magnetic storage unit; fabricating a magnetic tunnel junction stack on the bottom electrode and obtaining one or more actual parameters of the magnetic tunnel junction stack; comparing the actual parameters with corresponding first preset parameters to determine a comparison result; determining process parameters of a reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result; forming the reference resistance according to the determined process parameters.

2. The method according to claim 1, characterized in that, The obtaining one or more actual parameters of the magnetic tunnel junction stack includes: obtaining an actual thickness parameter of the magnetic tunnel junction stack and / or an actual planar size parameter of the magnetic tunnel junction stack.

3. The method according to claim 2, characterized in that, The determining process parameters of a reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result includes: when a difference between the actual thickness parameter of the magnetic tunnel junction stack and a first preset thickness parameter in the first preset parameters is greater than a first preset threshold, adjusting a second preset thickness parameter of the reference resistance so that a difference between a read window in a high resistance state and a read window in a low resistance state of the magnetic tunnel junction is not greater than a third preset threshold.

4. The method according to claim 2, characterized in that, The determining process parameters of a reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result includes: when a difference between the actual planar size parameter of the magnetic tunnel junction stack and a first preset planar size parameter in the first preset parameters is greater than a second preset threshold, adjusting a second preset planar size parameter of the reference resistance so that a difference between a read window in a high resistance state and a read window in a low resistance state of the magnetic tunnel junction is not greater than a third preset threshold.

5. The method according to claim 2, characterized in that, The determining process parameters of a reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result includes: when a difference between the actual thickness parameter of the magnetic tunnel junction stack and a first preset thickness parameter in the first preset parameters is greater than a first preset threshold, adjusting a second preset planar size parameter of the reference resistance so that a difference between a read window in a high resistance state and a read window in a low resistance state of the magnetic tunnel junction is not greater than a third preset threshold.

6. The method according to claim 2, characterized in that, The determining process parameters of a reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result includes: when a difference between the actual planar size parameter of the magnetic tunnel junction stack and a first preset planar size parameter in the first preset parameters is greater than a second preset threshold, adjusting a second preset thickness parameter of the reference resistance so that a difference between a read window in a high resistance state and a read window in a low resistance state of the magnetic tunnel junction is not greater than a third preset threshold.

7. The method according to claim 2, characterized in that, The determining process parameters of a reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result includes: obtaining a difference between the actual thickness parameter and the first preset thickness parameter in the first preset parameters; calculating a ratio of the difference to the first preset thickness parameter; multiplying a cross-sectional area corresponding to the second preset thickness parameter by the ratio to obtain a cross-sectional area that needs to be increased or decreased; obtaining an adjusted cross-sectional area according to the cross-sectional area corresponding to the second preset thickness parameter and the cross-sectional area that needs to be increased or decreased; determining an adjusted second preset thickness parameter or a second preset planar size parameter according to the adjusted cross-sectional area.

8. The method according to claim 2, characterized in that, The process parameters for determining the reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result include: Obtain the difference between the actual planar dimension parameter and the first preset planar dimension parameter in the first preset parameters; Calculate the ratio of the difference to the first preset planar dimension parameter; Multiply the cross-sectional area corresponding to the second preset planar dimension parameter by the ratio to obtain the cross-sectional area that needs to be increased or decreased; Obtain the adjusted cross-sectional area based on the cross-sectional area corresponding to the second preset planar dimension parameter and the cross-sectional area that needs to be increased or decreased; Determine the adjusted second preset planar dimension parameter or the adjusted second preset thickness parameter based on the adjusted cross-sectional area.

9. The method according to claim 2, characterized in that, The process parameters for determining the reference resistance corresponding to the magnetic tunnel junction stack according to the comparison result include: When the difference between the actual thickness parameter of the magnetic tunnel junction stack and the first preset thickness parameter is not greater than the first preset threshold, and the difference between the actual planar dimension parameter of the magnetic tunnel junction stack and the first preset planar dimension parameter is not greater than the second preset threshold; determine the second preset thickness parameter and the second preset planar dimension parameter of the reference resistance as the process parameters of the reference resistance corresponding to the magnetic tunnel junction.

10. The method according to claim 1, characterized in that,Forming the reference resistance according to the determined process parameters includes: Form a reference resistance thin film on the substrate; Perform patterning on the reference resistance thin film to form a reference resistance; wherein, both ends of the reference resistance in the length direction are electrically connected to a reference circuit.

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