Method for detecting design flaws in sti hole structures

Abstract

The application provides a method for detecting defects of STI hole structure design, which comprises the following steps: providing a substrate, forming a pad oxide layer on the substrate, and forming a hard mask layer on the pad oxide layer; forming a groove through the hard mask layer, the pad oxide layer and the substrate by photolithography and etching; forming a linear oxidation layer on the groove; dividing the substrate into a first region and a second region; irradiating the linear oxidation layer in the first region with a first light source to reduce the hydrogen bonds on the surface of the linear oxidation layer; irradiating the surface of the linear oxidation layer in the second region with a second light source to make the hydrogen bonds on the surface of the linear oxidation layer in the second region more than those in the first region; forming STI in each groove by deposition and grinding, and then removing the hard mask layer; and obtaining data of the hole structure in the first region and the second region and analyzing the design defects. The method for detecting defects of STI hole structure design does not need an additional wet cleaning process, can test multiple groups in a single wafer, and can save cost and time.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a method for detecting defects in the STI hole structure design. Background Technology

[0002] Defects are the primary cause of reduced chip manufacturing yield and reliability, making defect management and control particularly important in the semiconductor manufacturing process.

[0003] STI Void (Shallow Trench Isolation Void Structure) is a common defect caused by HARP (High Aspect Ratio Process) technology, and is often closely related to the process window and the weak point of the design rule.

[0004] The existing method for detecting this design flaw is to deposit STI through high aspect ratio process and chemical mechanical planarization grinding, and then perform wet washing on the SIN hard mask layer to expose the holes. This method requires additional time and multiple wafers for verification.

[0005] To address the aforementioned issues, a novel method for detecting design flaws in STI hole structures is needed. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a method for detecting STI hole structure design defects, which solves the problem that the existing technology for detecting STI hole structure design defects requires additional time and multiple wafers for verification during wet cleaning.

[0007] To achieve the above and other related objectives, this invention provides a method for detecting design flaws in STI hole structures, comprising:

[0008] Step 1: Provide a substrate, form an oxide pad layer and a hard mask layer on the substrate, and form a groove through the hard mask layer, the oxide pad layer and the substrate by photolithography and etching;

[0009] Step 2: Form a linear oxide layer on the groove;

[0010] Step 3: Divide the substrate into a first region and a second region. Irradiate the linear oxide layer in the first region with a first light source to reduce the number of hydrogen bonds on the surface of the linear oxide layer. Irradiate the surface of the linear oxide layer in the second region with a second light source to increase the number of hydrogen bonds on the surface of the linear oxide layer in the second region compared to the number of hydrogen bonds on the surface of the linear oxide layer in the first region.

[0011] Step 4: Form STI in each of the grooves by deposition and grinding, and then remove the hard mask layer, wherein a portion of the STI contains a cavity structure;

[0012] Step 5: Obtain data on the cavity structures in the first and second regions and analyze design shortcomings.

[0013] Preferably, the substrate in step one is a silicon substrate.

[0014] Preferably, the hard mask layer in step one is silicon nitride.

[0015] Preferably, the material of the oxygen pad layer in step one is silicon dioxide.

[0016] Preferably, the material of the linear oxide layer in step two is silicon dioxide.

[0017] Preferably, in step three, the substrate is divided into first to fourth quadrants, the first region being the region in the first and third quadrants, and the second region being the region in the second and fourth quadrants.

[0018] Preferably, the first light source in step three is ultraviolet light, and the second light source is non-ultraviolet light.

[0019] Preferably, the wavelength of the ultraviolet light in step three is 260 to 320 nanometers.

[0020] Preferably, the irradiation time of the linear oxide layer in the first and second regions in step three is different.

[0021] Preferably, the STI is formed in step four using a high aspect ratio process.

[0022] As described above, the method for detecting design flaws in the STI hole structure of the present invention has the following beneficial effects:

[0023] The detection method of the present invention does not require an additional wet washing process and can perform multiple test groups within a single wafer, which can save costs and time. Attached Figure Description

[0024] Figure 1 The diagram shown is a schematic representation of the detection method of the present invention.

[0025] Figure 2 The diagram shown illustrates the formation of the groove according to the present invention.

[0026] Figure 3 The diagram shown illustrates the formation of a linear oxide layer according to the present invention.

[0027] Figure 4 The diagram shows a schematic of the linear oxide layer in the first region being illuminated by a first light source according to the present invention.

[0028] Figure 5 The diagram shows a schematic of the linear oxide layer in the second region being illuminated by a second light source according to the present invention.

[0029] Figure 6 The diagram shown is a schematic representation of the deposition STI of the present invention.

[0030] Figure 7 The diagram shown is a schematic diagram of the grinding STI of the present invention;

[0031] Figure 8 The diagram shows the first and second regions of the present invention.

[0032] Figure 9 The diagram shows the distribution of the cavity structure in the first and second regions of the present invention.

[0033] Figure 10 The diagram shows the relationship between the number of cavities in this invention and the duration of ultraviolet irradiation. Detailed Implementation

[0034] 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.

[0035] Please see Figure 1 This invention provides a method for detecting design flaws in STI hole structures, including:

[0036] Step 1: Provide a substrate 10, form an oxide pad layer 11 and a hard mask layer 12 on the substrate 10, and form a groove 13 through the hard mask layer 12, the oxide pad layer 11, and the substrate 10 by photolithography and etching. Specifically, form a photoresist layer on the hard mask layer 12, and partially open the photoresist layer by photolithography to expose the underlying hard mask layer 12 to define the area of ​​the etching groove 13. Then, dry etch the hard mask layer 12, the oxide pad layer 11, and the substrate 10 to form the groove 13, forming a groove as shown in the image. Figure 2 The structure shown;

[0037] In an embodiment of the present invention, the substrate 10 in step one is a silicon substrate 10.

[0038] In an embodiment of the present invention, the hard mask layer 12 in step one is silicon nitride, which can be formed by chemical vapor deposition.

[0039] In an embodiment of the present invention, the material of the oxygen pad layer 11 in step one is silicon dioxide, which can be formed by thermal oxidation of the silicon substrate 10 in a high-temperature furnace tube.

[0040] Step two, a linear oxide layer 14 is formed on the groove 13, forming a shape like... Figure 3 The structure shown;

[0041] In an embodiment of the present invention, the material of the linear oxide layer 14 in step two is silicon dioxide. The linear oxide layer 14 is an oxide layer formed in a high-temperature furnace tube, and its function is as follows:

[0042] ① Repairing substrate damage caused by STI17 etching;

[0043] ② Round off the sharp corners caused by STI17 etching.

[0044] Step 3: Divide substrate 10 into first and second regions. Please refer to [link / reference]. Figure 4 The linear oxide layer 14 in the first region is irradiated by the first light source 15, thereby reducing the hydrogen bonds on the surface of the linear oxide layer 14; see also Figure 5 The surface of the linear oxide layer 14 in the second region is irradiated by the second light source 16, so that there are more hydrogen bonds on the surface of the linear oxide layer 14 in the second region than on the surface of the linear oxide layer in the first region. That is, the second region can be irradiated by a light source that does not destroy hydrogen bonds or has a poor effect on destroying hydrogen bonds.

[0045] In an embodiment of the present invention, please refer to Figure 8 In step three, the substrate 10 is divided into the first to the fourth quadrant. The first region is the region in the first and third quadrants, and the second region is the region in the second and the fourth quadrants.

[0046] In an embodiment of the present invention, the first light source 15 in step three is ultraviolet (UV) and the second light source 16 is non-UV (none UV). Ultraviolet light can reduce surface hydrogen bonds, accelerate the surface migration rate of tetraethoxysilane, and speed up the nucleation rate of high aspect ratio processes, thereby enhancing the extension of the step head and making it easier to form a cavity structure 18 at the design defect.

[0047] In an embodiment of the present invention, the wavelength of the ultraviolet light in step three is 260 to 320 nanometers.

[0048] In an embodiment of the present invention, the irradiation time of the linear oxide layer 14 in the first and second regions in step three is different.

[0049] Step four involves depositing and grinding STI17 in each groove 13. Specifically, this involves depositing the insulating material filling the groove 13 to form an STI17. Figure 6 The structure shown typically uses an oxide as the insulating material. The insulating material is then ground using a chemical mechanical planarization (CMP) process to form STI17. Afterward, the hard mask layer 12 is removed. Void structures 18 are formed in some of the STI17, resulting in structures like... Figure 7 The structure shown;

[0050] In an embodiment of the present invention, STI17 is formed in step four using a high aspect ratio process.

[0051] Step 5: Obtain data on the hole structure 18 in the first and second regions and analyze the design defects. Specifically, based on the number distribution of the collected STI17 hole structure 18, the design defects of the STI17 hole structure 18 in different regions of the wafer can be obtained, which can provide a reference for the design margin.

[0052] In an embodiment of the present invention, the distribution diagram of STI17 hole structure 18 obtained from the first and second regions is as follows: Figure 9 As shown, the irradiation time of ultraviolet light and the corresponding number of hole structures 18 are changed as follows: Figure 10 As shown, this means that multiple test groups can be performed on a single wafer, which can save costs and time.

[0053] 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.

[0054] In summary, the detection method of the present invention does not require an additional wet washing process and can perform multiple test groups within a single wafer, saving costs and time. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0055] 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 detecting design flaws in STI hole structures, characterized in that, At least including: Step 1: Provide a substrate, form an oxide pad layer and a hard mask layer on the substrate, and form a groove through the hard mask layer, the oxide pad layer and the substrate by photolithography and etching; Step 2: Form a linear oxide layer on the groove; Step 3: Divide the substrate into a first region and a second region. Irradiate the linear oxide layer in the first region with a first light source, i.e., ultraviolet light, to reduce the hydrogen bonds on the surface of the linear oxide layer. Irradiate the surface of the linear oxide layer in the second region with a second light source, i.e., non-ultraviolet light, to increase the number of hydrogen bonds on the surface of the linear oxide layer in the second region compared to the number of hydrogen bonds on the surface of the linear oxide layer in the first region. Step 4: Form STI in each of the grooves by deposition and grinding, and then remove the hard mask layer, wherein a portion of the STI contains a cavity structure; Step 5: Obtain data on the hole structures in the first and second regions, and analyze the design shortcomings of the hole structures in different regions of the substrate based on the number distribution of the hole structures collected in the first and second regions.

2. The method for detecting design defects in STI hole structures according to claim 1, characterized in that: The substrate mentioned in step one is a silicon substrate.

3. The method for detecting design defects in STI hole structures according to claim 1, characterized in that: The hard mask layer in step one is silicon nitride.

4. The method for detecting design defects in STI hole structures according to claim 1, characterized in that: The material of the oxygen pad layer in step one is silicon dioxide.

5. The method for detecting design defects in STI hole structures according to claim 1, characterized in that: The material of the linear oxide layer in step two is silicon dioxide.

6. The method for detecting design defects in STI hole structures according to claim 1, characterized in that: In step three, the substrate is divided into the first to the fourth quadrant, with the first region being the region in the first and third quadrants, and the second region being the region in the second and the fourth quadrants.

7. The method for detecting design defects in STI hole structures according to claim 1, characterized in that: The wavelength of the ultraviolet light in step three is 260 to 320 nanometers.

8. The method for detecting design defects in STI hole structures according to claim 1, characterized in that: In step three, the irradiation time of the linear oxide layer in the first and second regions is different.

9. The method for detecting design defects in STI hole structures according to claim 1, characterized in that: In step four, the STI is formed using a high aspect ratio process.

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