Method of defining read-only memory encoding mode using metal wire
By utilizing the loading effect between the metal wire and the top metal layer, and using photolithography energy to define photoresist residue and sever the metal wire, the process problem caused by the design position of the metal wire in semiconductor manufacturing is solved, and efficient definition of the read-only memory encoding mode is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI HUAHONG GRACE SEMICON MFG CORP
- Filing Date
- 2025-01-23
- Publication Date
- 2026-08-04
AI Technical Summary
In semiconductor manufacturing, the design positions of metal wires vary, leading to specific process problems at certain locations that are difficult to solve effectively with existing technologies.
By utilizing the loading effect between the metal wire and the adjacent top metal layer, the photoresist residue is defined by different lithography energies without the need for an additional photomask. The encoding mode of the read-only memory is defined by cutting the metal wire, and the encoding mode is determined by the disconnection and connection of the metal wire.
This invention enables the effective definition of the encoding mode of read-only memory by adding an extra metal wire etching step without adding a photomask, thus solving the process problem and improving manufacturing efficiency.
Smart Images
Figure CN119947096B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor technology, and in particular to a method for defining the encoding mode of a read-only memory using a metal wire. Background Technology
[0002] In the semiconductor manufacturing process, the design location of the customer's metal fuse varies, and specific process problems may occur in certain locations, causing abnormalities such as the customer's metal fuse burning out.
[0003] To solve the above problems, a novel method is needed to define the encoding mode of read-only memory using metal wires. Summary of the Invention
[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a method for defining the encoding mode of a read-only memory using a metal wire, which solves the problem that the design position of the metal wire varies in the prior art, and specific process problems will arise in special positions.
[0005] To achieve the above and other related objectives, the present invention provides a method for defining a read-only memory encoding mode using a metal wire, comprising:
[0006] Step 1: Provide a substrate and form a read-only memory semiconductor device on the substrate. The top of the semiconductor device includes an interlayer dielectric layer, multiple spaced metal wires located in the interlayer dielectric layer, and a top metal layer. The thickness of the interlayer dielectric layer above the top metal layer is greater than that above the metal wires. The top metal layer is located above the metal wires and one side is close to the metal wires. The disconnection or connection of the metal wires is used to determine the encoding mode of the read-only memory.
[0007] Step 2: A photoresist layer is formed on the interlayer dielectric layer, wherein the photoresist layer above the top metal layer and the area near the metal wire is thicker;
[0008] Step 3: Select the required encoding mode and corresponding photolithography energy for different products, and use the loading effect of the photoresist layer on the adjacent metal and the top metal layer to open the photoresist layer on each product using the photomask defining the top metal layer and the corresponding photolithography energy.
[0009] Step 4: Etch the corresponding metal wires according to the coding pattern of each product.
[0010] Preferably, the material of the interlayer dielectric layer in step one is an oxide.
[0011] Preferably, the top metal layer is present on all three sides of the metal wire used to define the encoding mode of the read-only memory in step one.
[0012] Preferably, the encoding mode of the read-only memory in step one includes the first to third encoding modes.
[0013] Preferably, in step three, the first to third encoding modes are defined based on the disconnection and connection status of the first and second metal wires.
[0014] Preferably, in step three, the first encoding mode is defined by the fact that both the first and second metal wires are connected.
[0015] Preferably, in step three, the second encoding mode is defined by connecting the first metal wire and disconnecting the second metal wire.
[0016] Preferably, in step three, the third encoding mode is defined by disconnecting both the first and second metal wires.
[0017] Preferably, in step three, the photoresist layer is opened using an i-line projection stepper.
[0018] Preferably, the etching method in step four is dry etching.
[0019] As described above, the method of defining the encoding mode of a read-only memory using a metal wire according to the present invention has the following beneficial effects:
[0020] This invention utilizes the loading effect between the metal wires and the adjacent top metal layer to define the photoresist residue above several metal wires near the short side by using different photolithography energies without the need for a photomask. Then, the exposed metal wires are etched to define the encoding mode type of the read-only memory. This process only requires one additional metal wire etching step. Attached Figure Description
[0021] Figure 1 The diagram shown is a schematic representation of the process flow of the present invention.
[0022] Figure 2 The diagram shown illustrates the formation of the photoresist layer according to the present invention.
[0023] Figure 3 The diagram shown is an illustration of the invention title of one embodiment;
[0024] Figure 4 The diagram shown is a schematic representation of the first encoding mode of the present invention.
[0025] Figure 5 This is a schematic diagram of the second encoding mode of the present invention;
[0026] Figure 6 The diagram shown is a schematic representation of the third encoding mode of the present invention.
[0027] Figure 7 This diagram illustrates the load effect of the top metal layer of the three-sided loop of the metal wire according to the present invention. Detailed Implementation
[0028] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.
[0029] Please see Figure 1 This invention provides a method for defining the encoding mode of a read-only memory using a metal wire, comprising:
[0030] Step 1: Provide a substrate and form a read-only memory semiconductor device on the substrate. The top of the semiconductor device includes an interlayer dielectric layer 101, multiple spaced metal wires 102 and a top metal layer 103 located in the interlayer dielectric layer 101. The thickness of the interlayer dielectric layer 101 above the metal wires 102 is thicker than that above the metal wires 102. The top metal layer 103 is located above the metal wires 102 and one side is close to the metal wires 102. The disconnection and connection status of the metal wires 102 are used to determine the encoding mode of the read-only memory.
[0031] In some embodiments, the material of the interlayer dielectric layer 101 in step one is an oxide.
[0032] In some embodiments, please refer to Figure 7 In step one, the metal wire 102 used to define the encoding mode of the read-only memory has a top metal layer 103 on three sides. The loading effect of the top metal layer 103 around the metal wire 1023 is utilized (e.g., Figure 7 The top metal layer 103 at the rectangular frame, without the need for a photomask, defines several metal wires 102 near the short side using different photolithography energies (e.g., Figure 7 The photoresist residue on the metal wire 102 at the circle is then cut off to define the encoding mode type of the read-only memory. This process only requires one more step of etching the metal wire 102.
[0033] In some embodiments, the encoding mode of the read-only memory in step one includes the first to third encoding modes. It should be noted that in other embodiments, the encoding mode of the read-only memory can also be other types of encoding modes, and the corresponding state of the wire 102 can also be adjusted.
[0034] Step 2: A photoresist layer 104 is formed on the interlayer dielectric layer 101. The photoresist layer 104 above the top metal layer 103 and the metal wire 102 is thicker, forming a layer as shown in the image. Figure 2 The structure shown;
[0035] Step 3: Select the required encoding mode and corresponding lithography energy for different products. Utilize the loading effect of the photoresist layer 104 on the adjacent metal and top metal layer 103, and open the photoresist layer 104 on each product using the photomask defining the top metal layer and the corresponding lithography energy. Normally, when a customer upgrades from version V1 to version V2, they may need to update the metal layer below the top metal 103, which requires a new photomask. In this invention, the customer pre-designs the circuitry on the metal layer below the top metal 103, and then defines different versions by connecting and disconnecting the metal wires 102, utilizing the deposition effect of the photoresist. This eliminates the need for an additional photomask.
[0036] In some embodiments, the first to third encoding modes are defined in step three based on the disconnection and connection status of the first and second metal wires (1021, 1022).
[0037] In some embodiments, please refer to Figure 4 In step three, the first encoding mode is defined by connecting the first and second metal wires (1021, 1022).
[0038] In some embodiments, please refer to Figure 5 In step three, the first metal wire 1021 is connected and the second metal wire 1022 is disconnected to define the second encoding mode.
[0039] In some embodiments, please refer to Figure 6 In step three, the third encoding mode is defined by disconnecting both the first and second metal wires (1021, 1022).
[0040] In some embodiments, step three involves using an i-line projection stepper to open the photoresist layer 104.
[0041] For example, please see Figure 3 The metal wire 102 has a thickness of 0.45 μm, a spacing of 4 μm, a width of 0.8 μm, and a distance of 3.5 μm from the metal wire 102 to the window opening.
[0042] The thickness of the top metal layer 103 is 4 μm, and the distance from the three-sided window of the metal wire 102 to the nearby top metal layer 103 is 6.5 μm;
[0043] The thickness of the interlayer dielectric layer 101 on the top metal layer 103 is 3.25 μm, and the thickness of the photoresist layer 104 is 5 μm.
[0044] The lithography energies corresponding to the first to third encoding modes are 550 milliseconds, 650 milliseconds, and 750 milliseconds, respectively, and the equipment is an i-line projection stepper.
[0045] Step 4: Etch the corresponding metal wire 102 according to the coding pattern of each product.
[0046] In some embodiments, the etching method in step four is dry etching.
[0047] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.
[0048] In summary, this invention utilizes the loading effect between the metal wires and the adjacent top metal layer to define the photoresist residue above several metal wires near the short side using different photolithography energies without requiring a photomask. The exposed metal wires are then etched to define the encoding mode type of the read-only memory. This process only requires an additional metal wire etching step. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and has high industrial applicability.
[0049] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.
Claims
1. A method for defining a read-only memory encoding pattern with a wire, characterized by, At least including: Step 1: Provide a substrate and form a read-only memory semiconductor device on the substrate. The top of the semiconductor device includes an interlayer dielectric layer, multiple spaced metal wires located in the interlayer dielectric layer, and a top metal layer. The thickness of the interlayer dielectric layer above the top metal layer is greater than that above the metal wires. The top metal layer is located above the metal wires and one side is close to the metal wires. The top metal layer is present on three sides of the metal wires used to define the encoding mode of the read-only memory. The disconnection or connection of the metal wires is used to determine the encoding mode of the read-only memory. Step 2: A photoresist layer is formed on the interlayer dielectric layer, wherein the photoresist layer above the top metal layer and the area near the metal wire is thicker; Step 3: Select the required encoding mode and corresponding photolithography energy for different products, utilize the loading effect of the adjacent metal and the photoresist layer on the top metal layer, and open the photoresist layer on each product using the photomask defining the top metal layer and the corresponding photolithography energy; Step 4: Etch the corresponding metal wires according to the coding pattern of each product.
2. The method of claim 1, wherein: The material of the interlayer dielectric layer in step one is an oxide. 3. The method of claim 1, wherein: The encoding modes of the read-only memory mentioned in step one include the first to third encoding modes. 4. The method of claim 3, wherein: In step three, the first to third encoding modes are defined based on the disconnection and connection status of the first and second metal wires. 5. The method of claim 4, wherein: In step three, the first encoding mode is defined by the fact that both the first and second metal wires are connected. 6. The method of claim 4, wherein: In step three, the second encoding mode is defined by connecting the first metal wire and disconnecting the second metal wire. 7. The method of claim 4, wherein: In step three, the third encoding mode is defined by disconnecting both the first and second metal wires. 8. The method of claim 1, wherein: In step three, the photoresist layer is opened using an i-line projection stepper. 9. The method of claim 1, wherein: The etching method described in step four is dry etching.