Contact window defect detection method
By preparing a metal layer on the surface of the element to be tested and optical defect detection is performed, the problem of difficulty in detecting contact window defects in the prior art is solved, effective detection of these defects is achieved, and the pass rate and performance of semiconductor devices are improved.
Patent Information
- Application Number
- CN202311526439.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-15
- Publication Date
- 2025-05-16
AI Technical Summary
The existing contact window defect detection methods are difficult to effectively detect defects with smaller sizes, which affects the conductivity of semiconductor devices.
The metal layer is prepared on the surface of the element to be tested, and the contact window is covered, and then the detection is performed using an optical defect detection method. The detection signal ratio is increased by the metal layer reflected signal to achieve effective detection of defects with smaller sizes.
By improving the reflected signal of the metal layer, contact window defects with smaller sizes can be effectively detected, and the pass rate and performance of semiconductor device products can be improved.
Smart Images
Figure CN120015641A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a contact window defect detection method. Background Art
[0002] In the semiconductor manufacturing process, ILD (Inter Layer Dielectric) is an insulating material layer used to isolate circuit elements. Its preparation method is usually to form a groove after exposure and etching, and then deposit titanium and titanium nitride in sequence through physical or chemical vapor deposition to form a contact window bonding layer, and then fill metal tungsten in the groove as a conductive layer, and finally form a complete contact window link by physical mechanical grinding. In the process of forming the contact window, contact window defects may occur due to material characteristics or process reasons. When there are small defects, there is a chance that tungsten voids will be formed when filling metal tungsten, thereby affecting the conductive performance of the contact window. It is difficult to effectively detect small defects in the current contact window defect detection method. Summary of the invention
[0003] The purpose of the present disclosure is to provide a contact window defect detection method to improve the detection effect of contact window defects with smaller sizes.
[0004] In order to achieve the above object, the present disclosure provides a contact window defect detection method, the method comprising:
[0005] Acquire a component to be tested, wherein the component to be tested has a contact window;
[0006] Prepare a metal layer on the surface of the device under test so that the metal layer covers the contact window, thereby obtaining a device under test having a metal layer formed thereon;
[0007] Optical defect detection is performed on the component to be tested having the metal layer formed thereon.
[0008] Optionally, the material of the metal layer includes at least one of titanium nitride, tantalum nitride and tungsten nitride.
[0009] Optionally, the thickness of the metal layer is 3-15 nm.
[0010] Optionally, the metal layer is prepared by at least one of chemical vapor deposition, physical vapor deposition and atomic layer deposition.
[0011] Optionally, the metal layer is a titanium nitride layer, and the preparation conditions of the titanium nitride layer include: a deposition temperature of 300 to 600° C. and a deposition time of 30 to 120 s.
[0012] Optionally, the optical defect detection method is a bright field defect detection method and / or a dark field defect detection method.
[0013] Optionally, the optical defect detection is a bright field defect inspection method, and the detection conditions of the bright field defect inspection method include: 50nm pixel, blue band light wave, and reflected light collection mode.
[0014] Optionally, the performing optical defect detection on the device to be tested having the metal layer formed thereon comprises:
[0015] Acquiring a defect reflection signal of the contact window;
[0016] A detection result of the contact window defect is obtained according to the defect reflection signal.
[0017] Optionally, the size of the contact window defect is 30-500 nm.
[0018] Optionally, the method further comprises the step of removing the metal layer after the optical defect detection is completed.
[0019] Through the above technical scheme, the present invention first prepares a metal layer on the surface of the component to be tested, and then performs optical defect detection on the component to be tested with the metal layer formed thereon, and improves the signal ratio obtained by the optical defect detection through the reflection signal of the metal layer, thereby achieving effective detection of smaller contact window defects and improving the qualification rate and performance of semiconductor device products.
[0020] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:
[0022] Figure 1 It is a flow chart of a specific implementation of the contact window defect detection method provided by the present disclosure.
[0023] Figure 2 It is a structural schematic diagram of a specific implementation of the component to be tested in the contact window defect detection method provided in the present disclosure.
[0024] Figure 3 It is a structural schematic diagram of a specific implementation of the element to be tested having a metal layer formed thereon in the contact window defect detection method provided in the present disclosure.
[0025] Description of Reference Numerals
[0026] 1—contact window, 2—defect, 3—metal layer, 4—substrate, 5—polysilicon gate, 6—interlayer dielectric. DETAILED DESCRIPTION
[0027] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.
[0028] The present invention provides a contact window defect detection method, referring to Figure 1 The method comprises the following steps S101 to S103:
[0029] S101, obtaining a component to be tested, wherein the component to be tested has a contact window;
[0030] S102, preparing a metal layer on the surface of the device under test so that the metal layer covers the contact window, thereby obtaining a device under test having a metal layer formed thereon;
[0031] S103, performing optical defect detection on the component to be tested having the metal layer formed thereon.
[0032] According to the present disclosure, the component to be tested can be any semiconductor device with a contact window defect detection requirement, such as an integrated circuit component. In the method disclosed in the present disclosure, a metal layer is prepared on the surface of the component to be tested and then optical defect detection is performed on the component to be tested with the metal layer formed thereon, and the signal ratio obtained by the optical defect detection is improved by the reflection signal of the metal layer at the contact window defect, thereby achieving effective detection of contact window defects of smaller size and improving the qualified rate and performance of semiconductor device products.
[0033] In step S101, there is no special limitation on the preparation process and specific structure of the DUT, as long as it has a contact hole, for example, Figure 2 The device under test of an embodiment is shown, the device comprises a substrate 4, a polysilicon gate (Poly Gate) 5 and an interlayer dielectric (ILD) 6 are formed on the substrate, the interlayer dielectric 6 is spaced apart to form a contact window 1, the contact window 1 may have a defect 2, the position of the defect 2 is not particularly limited, as long as it is located in the area of the contact window 1, it is a contact window defect, for example, it may be at the opening of the contact window 1, etc. The types of the defect 2 may include, for example, a particle defect, a polymer defect, or a residual defect, etc.
[0034] In step S102, the metal layer may be any common metal material, such as titanium-containing material, tantalum-containing material, tungsten-containing material, copper-containing material, etc. In one embodiment, the material of the metal layer may include at least one of titanium nitride, tantalum nitride and tungsten nitride. Furthermore, the material of the metal layer is preferably titanium nitride, and the metal layer is a titanium nitride layer. The titanium nitride layer prepared on the surface of the component to be tested can be used as the metal layer for the optical defect detection, and can also be used as a functional layer (such as a contact window bonding layer, etc.) in the subsequent process of the semiconductor device, without the need to remove it after the optical defect detection is completed.
[0035] Figure 3 The structure diagram of the DUT formed with a metal layer in an embodiment is a schematic diagram, wherein the metal layer 3 covers the contact window 1, which means that the metal layer 3 at least covers the interlayer dielectric 6 around the contact window 1, so that the metal layer covers the surface of the contact window defect. The thickness of the metal layer 3 can be 3 to 15 nm.
[0036] The metal layer 3 can be prepared on the surface of the DUT by a common method in the art. Specifically, the preparation method of the metal layer 3 can be at least one of chemical vapor deposition, physical vapor deposition and atomic layer deposition. In one embodiment, the metal layer 3 is a titanium nitride layer, which is prepared by chemical vapor deposition. Further, the preparation conditions of the titanium nitride layer include: a deposition temperature of 300 to 600°C and a deposition time of 30 to 120s.
[0037] In step S103, the optical defect detection method may be a method commonly used in the art for detecting defects in semiconductor devices. For example, the optical defect detection method may be a bright-field inspection method and / or a dark-field inspection method.
[0038] In one embodiment, the optical defect detection is a bright field defect inspection method, and the detection equipment and specific operation steps used may be common and well known in the art. For example, the detection conditions may include: 50nm pixels, blue band light waves, and reflected light collection mode.
[0039] According to the present disclosure, since the metal layer 3 covers the contact window 1, when the contact window 1 has a defect 2, the contact window defect is also covered by the metal layer 3. Thus, when the optical defect detection is performed, the presence of the metal layer 3 covering the contact window defect is conducive to obtaining an increased defect reflection signal, thereby achieving effective detection of contact window defects with smaller sizes. Specifically, the optical defect detection of the component to be tested having the metal layer formed thereon includes:
[0040] Acquiring a defect reflection signal of the contact window;
[0041] A detection result of the contact window defect is obtained according to the defect reflection signal.
[0042] The detection result of the contact window defect may include whether there is a contact window defect, the size of the contact window defect, etc. The present disclosure can effectively detect smaller contact window defects, specifically, the size of the contact window defect may be 30-500 nm.
[0043] Furthermore, the method may also include the step of removing the metal layer after the contact window defect detection is completed, especially when the material of the metal layer cannot be used to form the functional layer of the device under test, by removing the metal layer, it is possible to achieve contact window defect detection while avoiding the impact on subsequent preparation processes and device performance. The method of removing the metal layer can be well known in the art, such as removing the metal layer by grinding, pickling, dry etching, etc.
[0044] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.
[0045] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.
[0046] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.
Claims
1. A contact window defect detection method, characterized in that: The method includes: Acquire a component to be tested, wherein the component to be tested has a contact window; Prepare a metal layer on the surface of the device under test so that the metal layer covers the contact window, thereby obtaining a device under test having a metal layer formed thereon; Optical defect detection is performed on the component to be tested having the metal layer formed thereon.
2. The method according to claim 1, wherein: The material of the metal layer includes at least one of titanium nitride, tantalum nitride and tungsten nitride.
3. The method according to claim 1, wherein: The thickness of the metal layer is 3-15 nm.
4. The method according to claim 1, wherein: The metal layer is prepared by at least one of chemical vapor deposition, physical vapor deposition and atomic layer deposition.
5. The method according to claim 1, wherein: The metal layer is a titanium nitride layer, and the preparation conditions of the titanium nitride layer include: a deposition temperature of 300 to 600° C. and a deposition time of 30 to 120 seconds.
6. The method according to claim 1, wherein: The optical defect detection method is a bright field defect detection method and / or a dark field defect detection method.
7. The method according to claim 1, wherein: The optical defect detection is a bright field defect inspection method, and the detection conditions of the bright field defect inspection method include: 50nm pixel, blue band light wave, and reflected light collection mode.
8. The method according to claim 1, wherein: The optical defect detection of the component to be tested having the metal layer formed thereon comprises: Acquiring a defect reflection signal of the contact window; A detection result of the contact window defect is obtained according to the defect reflection signal.
9. The method according to claim 8, wherein: The size of the contact window defect is 30-500 nm.
10. The method according to claim 1, wherein: The method further comprises the step of removing the metal layer after the optical defect detection is completed.