B&S machine organic contamination monitoring methods
By forming a metal barrier layer and a seed layer on the B&S instrument, and then vacuuming the measuring instrument to collect contaminant clusters, the problem of difficult component replacement was solved, and effective monitoring of organic contamination was achieved, thereby improving the reliability and yield of semiconductor devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUA HONG SEMICON WUXI LTD
- Filing Date
- 2023-06-16
- Publication Date
- 2026-08-04
AI Technical Summary
In existing B&S equipment for monitoring organic contamination, it is difficult to replace damaged parts, which affects the reliability and yield of semiconductor devices.
After forming the metal barrier layer and the metal seed layer, the chamber of the measuring instrument is evacuated to move organic contaminants to the side wall near the top of the contact hole and they gather into contaminant clusters, increasing their diameter. YE measurement is performed before the metal body layer is formed to monitor large-size void defects.
It enables timely and effective monitoring of organic contamination on B&S machines, avoids difficulties in replacing parts, and improves the feasibility and reliability of monitoring.
Smart Images
Figure CN116825655B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor manufacturing technology, specifically to a method for monitoring organic contamination on B&S machines. Background Technology
[0002] B&S (Barrier and Seed) machines (such as the AMAT Endura machine) are widely used in production. Their main function is to generate barrier and seed layers for metal wires (such as copper wires). If organic matter contaminates the B&S machine, it will cause the subsequent metal material growth to be poor and form hole defects on the metal wire, affecting the reliability and yield of the final product (semiconductor device).
[0003] Current B&S (Browser & Sink) machines use RGA (Residual Gas Analysis) for monitoring. However, the relevant components are only available in a few countries and their export is restricted, resulting in a severe shortage and high cost of these components. Furthermore, replacing damaged components using RGA is difficult. To avoid impacting the reliability and yield of the final product, a new method for monitoring organic contamination in B&S machines is urgently needed. Summary of the Invention
[0004] This application provides a method for monitoring organic contamination on B&S machines, which can solve the problem that it is difficult to replace damaged parts when using existing RGA methods to monitor organic contamination.
[0005] On the one hand, embodiments of this application provide a method for monitoring organic contamination on B&S machines, including:
[0006] A substrate is provided on which stacked multilayer dielectric layers are formed, and contact holes are formed in the multilayer dielectric layers;
[0007] A metal barrier layer and a metal seed layer are formed using a B&S machine. The metal barrier layer covers the top dielectric layer and the bottom and side walls of the contact hole, and the metal seed layer covers the metal barrier layer.
[0008] The first semiconductor structure is transferred to the measuring instrument and the chamber of the measuring instrument is evacuated to allow organic contaminants to move to the side wall near the top of the contact hole and the surface of the first semiconductor structure and accumulate into contaminant clusters. The first semiconductor structure is the semiconductor structure formed after the metal barrier layer and the metal seed layer are formed.
[0009] A metal body layer is formed, which covers the metal seed layer in the contact hole and fills the remaining space of the contact hole;
[0010] Remove the metal body layer that extends beyond the top of the contact hole;
[0011] Perform post-contamination YE measurements to monitor the contamination clusters on the B&S machine in a timely manner.
[0012] Optionally, in the method for monitoring organic contamination of the B&S machine, the step of transferring the first semiconductor structure to the measurement machine and evacuating the chamber of the measurement machine is to perform preliminary YE measurement.
[0013] Optionally, in the method for monitoring organic contamination on the B&S machine, the preliminary YE measurement includes:
[0014] The first semiconductor structure is scanned using UV light under normal pressure to obtain defects forming on the surface of the first semiconductor structure;
[0015] The chamber of the measuring instrument is evacuated, and the surface of the first semiconductor structure is bombarded with an electron beam in a vacuum environment. Scattered electrons and secondary electrons from the surface of the first semiconductor structure are collected to obtain the defects on the surface of the first semiconductor structure.
[0016] Optionally, in the method for monitoring organic contamination of the B&S machine, during the process of evacuating the chamber of the measuring machine, the vacuum level inside the chamber of the measuring machine is <10^-7 Torr.
[0017] Optionally, in the method for monitoring organic contamination of the B&S machine, an electrochemical plating process is used to form the metal substrate layer.
[0018] Optionally, in the method for monitoring organic contamination on the B&S machine, the subsequent YE measurement includes:
[0019] Under normal pressure, UV light is used to scan the second semiconductor structure to obtain the defects forming the surface of the second semiconductor structure, wherein the second semiconductor structure is the semiconductor structure after removing the metal body layer that extends beyond the top of the contact hole;
[0020] The chamber of the measuring instrument is evacuated, and the surface of the second semiconductor structure is bombarded with an electron beam in a vacuum environment. Scattered electrons and secondary electrons from the surface of the second semiconductor structure are collected to obtain the defects on the surface of the second semiconductor structure.
[0021] Optionally, in the method for monitoring organic contamination of the B&S machine, during the process of evacuating the chamber of the measuring machine, the vacuum level inside the chamber of the measuring machine is <10^-7 Torr.
[0022] Optionally, in the method for monitoring organic contamination of the B&S machine, a chemical mechanical polishing process is used to remove the metal body layer extending beyond the top of the contact hole.
[0023] Optionally, in the method for monitoring organic contamination of the B&S instrument, during the process of evacuating the chamber of the measuring instrument to move the organic contaminants to the side wall near the top of the contact hole and the surface of the first semiconductor structure and agglomerate them into contaminant clusters, the diameter of the contaminant clusters is greater than or equal to 0.1 μm.
[0024] Optionally, in the method for monitoring organic contamination of the B&S machine, the metal barrier layer is formed using a physical vapor deposition process; the metal seed layer is formed using a physical vapor deposition process.
[0025] The technical solution of this application has at least the following advantages:
[0026] This application involves evacuating the chamber of the measurement instrument after forming the metal barrier layer and the metal seed layer, and before forming the metal body layer. This allows organic contaminants at the bottom of the contact hole to be moved to the sidewall near the top of the contact hole and to the surface of the first semiconductor structure (wafer). The organic contaminants are then aggregated into contaminant clusters, increasing their diameter. This results in large-sized voids in the metal body layer (conductive plug) that are easy to observe. In other words, the void size in the metal body layer (conductive plug) can be magnified during the formation of the metal body layer. This allows for timely and effective monitoring of all organic contaminants in the B&S instrument during subsequent YE measurements.
[0027] Furthermore, the method for monitoring organic contamination of B&S machines provided in this application does not use the RGA method to monitor organic contamination, thereby avoiding the difficulty of replacing damaged parts in existing B&S machine organic contamination monitoring methods. This breaks through the limitations of existing monitoring methods for organic contamination of B&S machines and increases the feasibility and reliability of monitoring organic contamination of B&S machines. Attached Figure Description
[0028] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0029] Figure 1 This is a flowchart of a method for monitoring organic contamination on a B&S machine according to an embodiment of the present invention;
[0030] Figure 2 This is a schematic diagram of the semiconductor structure after the formation of the metal barrier layer and the metal seed layer according to an embodiment of the present invention;
[0031] Figure 3 This is a schematic diagram of the semiconductor structure after the chamber of the measuring machine is evacuated according to an embodiment of the present invention;
[0032] Figure 4 This is a schematic diagram of the semiconductor structure after removing the metal body layer extending beyond the top of the contact hole according to an embodiment of the present invention;
[0033] The reference numerals in the attached figures are explained as follows:
[0034] 10-Substrate, 21-First dielectric layer, 22-Second dielectric layer, 23-Third dielectric layer, 24-Fourth dielectric layer, 25-Fifth dielectric layer, 26-Sixth dielectric layer, 27-Conductive plug, 28-Contact hole, 30-Metal barrier layer, 40-Metal seed layer, 51-Organic contamination, 52-Contamination cluster, 60-Metal host layer, 70-Void. Detailed Implementation
[0035] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0036] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0037] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0038] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.
[0039] This application provides a method for monitoring organic contamination on B&S machines, referring to... Figure 1 , Figure 1 This is a flowchart of a method for monitoring organic contamination on a B&S machine according to an embodiment of the present invention. The method for monitoring organic contamination on a B&S machine includes:
[0040] Step S10: Reference Figure 2 , Figure 2 This is a schematic diagram of the semiconductor structure after the formation of the metal barrier layer and the metal seed layer according to an embodiment of the present invention. A substrate 10 is provided, on which stacked multilayer dielectric layers are formed, and contact holes 28 are formed in the multilayer dielectric layers.
[0041] In some embodiments, the substrate 10 may be a semiconductor structure (wafer) formed after the front-end semiconductor device process, that is, some semiconductor film layers and patterns have been formed on the substrate 10.
[0042] In this embodiment, a 12-inch wafer can be used to monitor organic contamination on the B&S machine.
[0043] In some embodiments, the multilayer dielectric layer may include: a first dielectric layer 21, a second dielectric layer 22, a third dielectric layer 23, a fourth dielectric layer 24, a fifth dielectric layer 25, and a sixth dielectric layer 26. A conductive plug 27 may be formed in the first dielectric layer 21. The conductive plug 27 can also be understood as a metal wire. The material of the conductive plug 27 may be a metal such as copper or tungsten.
[0044] Furthermore, in this embodiment, the material of the first dielectric layer 21 can be silicon dioxide; the material of the second dielectric layer 22 can be SiCN; the material of the third dielectric layer 23 can be SiCOH; the material of the fourth dielectric layer 24 can be silicon dioxide; the material of the fifth dielectric layer 25 can be TiN; and the material of the sixth dielectric layer 26 can be silicon dioxide.
[0045] Step S20: Continue to refer to Figure 2 A metal barrier layer 30 and a metal seed layer 40 are formed using a B&S machine. The metal barrier layer 30 covers the top dielectric layer (sixth dielectric layer 26) and the bottom and side walls of the contact hole 28. The metal seed layer 40 covers the metal barrier layer 30.
[0046] Because there may be some organic contaminants inside the B&S machine, during the fabrication of the metal barrier layer 30 and the metal seed layer 40 on the B&S machine, these organic contaminants may adhere to the bottom of the contact hole 28, from... Figure 2 As can be seen, most of the small organic contaminants 51 on the B&S machine are located on the bottom wall of the contact hole 28 and on the side wall (lower half side wall) of the contact hole 28 near the bottom.
[0047] At this time, the diameter of the organic contaminants 51 on the bottom wall of the contact hole 28 and on the side wall (lower half side wall) near the bottom of the contact hole 28 is less than 0.1 μm, making them difficult to detect with a detection instrument (e.g., a measuring instrument).
[0048] In this embodiment, the metal barrier layer 30 can be formed using a physical vapor deposition process, such as magnetron sputtering; similarly, the metal seed layer 40 can also be formed using a physical vapor deposition process.
[0049] In some embodiments, the metal barrier layer 30 is made of copper; the metal seed layer 40 is made of copper.
[0050] Step S30: Reference Figure 3 , Figure 3 This is a schematic diagram of the semiconductor structure after evacuating the chamber of the measurement equipment according to an embodiment of the present invention. The first semiconductor structure is transferred to the measurement equipment, and the chamber of the measurement equipment is evacuated to allow organic contaminants 51 to move to the sidewall near the top of the contact hole 28 and to the surface of the first semiconductor structure, where they accumulate into contaminant clusters 52. The first semiconductor structure is the semiconductor structure formed after the metal barrier layer 30 and the metal seed layer 40 are formed; that is, the first semiconductor structure is... Figure 3 The semiconductor structure shown is illustrated. During the evacuation process of the measuring instrument's chamber, the vacuum level within the chamber is maintained at <10^-7 Torr.
[0051] In this embodiment, the chamber of the measuring instrument is evacuated to a vacuum level of 10^-8 Torr.
[0052] In some embodiments, evacuating the chamber of the measuring instrument allows organic contaminants 51 to move to the sidewall of the contact hole 28 near the top and the surface of the first semiconductor structure and aggregate into contaminant clusters 52. In these processes, the diameter of the contaminant clusters 52 on the sidewall of the contact hole 28 near the top and the surface of the first semiconductor structure is greater than or equal to 0.1 μm.
[0053] Furthermore, this embodiment does not impose any limitation on the type of measuring machine.
[0054] In some embodiments, the step of transferring the first semiconductor structure to a measurement instrument and evacuating the chamber of the measurement instrument comprises: performing preliminary YE measurement. The measurement instrument may be a YE measurement instrument.
[0055] Furthermore, the preliminary YE measurement includes:
[0056] First step: Scan the first semiconductor structure with UV light under normal pressure to obtain the defects forming the surface of the first semiconductor structure;
[0057] The second step is to evacuate the chamber of the YE measuring machine and bombard the surface of the first semiconductor structure with an electron beam in a vacuum environment to collect scattered electrons and secondary electrons from the surface of the first semiconductor structure in order to obtain the defects on the surface of the first semiconductor structure. During the evacuation process of the YE measuring machine chamber, the vacuum degree in the chamber of the YE measuring machine is ensured to be <10^-7 Torr.
[0058] In this application, by performing preliminary YE measurement after the formation of the metal barrier layer and the metal seed layer, and before the formation of the metal body layer, the following advantages are achieved: First, the chamber needs to be evacuated during the preliminary YE measurement process, which can move organic contaminants at the bottom of the contact hole to the sidewall near the top of the contact hole and the surface of the first semiconductor structure (wafer), and aggregate the organic contaminants into contaminant clusters, increasing the diameter of the organic contaminants. Second, performing preliminary YE measurement can more timely monitor some subtle defects in the first semiconductor structure, thereby enabling timely response strategies and improving work efficiency.
[0059] Step S40: Reference Figure 4 , Figure 4 This is a schematic diagram of the semiconductor structure after removing the metal body layer extending beyond the top of the contact hole according to an embodiment of the present invention. A metal body layer 60 is formed, which covers the metal seed layer 40 in the contact hole 28 and fills the remaining space of the contact hole 28. Because organic contaminants 51 move to the sidewalls of the contact hole 28 near the top and the surface of the first semiconductor structure and aggregate into contaminant clusters 52, the metal body layer 60 cannot be deposited at the locations of the contaminant clusters 52 after its formation, resulting in voids 70.
[0060] In some embodiments, the metal host layer 60 is formed using an electrochemical plating (ECP) process, wherein the metal host layer 60 can be understood as a conductive plug or a metal connecting wire. The main principle of the electrochemical plating (ECP) process is to use an electric current to provide electrons to replace metal ions with metal atoms to deposit and form the metal host layer 60 in the contact hole.
[0061] Furthermore, the metal body layer 60 can be made of copper.
[0062] In this application, after forming the metal barrier layer 30 and the metal seed layer 40, and before forming the metal body layer 60, the chamber of the measurement instrument is evacuated. This can move the organic contaminant 51 at the bottom of the contact hole to the side wall of the contact hole 28 near the top and to the surface of the first semiconductor structure (wafer). The organic contaminant 51 is then aggregated into contaminant clusters 52, increasing the diameter of the organic contaminant 51. This results in the formation of large-sized void defects in the metal body layer (conductive plug) that are easy to observe. In other words, the void size in the metal body layer (conductive plug) 60 can be enlarged during the formation of the metal body layer 60, so that all organic contaminants in the B&S instrument can be monitored in a timely and effective manner during the later YE measurement.
[0063] Step S50: Remove the metal body layer that extends beyond the top of the contact hole.
[0064] In some embodiments, a chemical mechanical polishing (CMP) process is used to remove the metal body layer 60 extending beyond the top of the contact hole 28 to planarize the metal body layer 60 at the top of the contact hole 28.
[0065] Step S60: Transfer the second semiconductor structure to the measurement equipment for subsequent YE measurement to monitor the contamination clusters on the B&S equipment in a timely manner.
[0066] In some embodiments, transferring the second semiconductor structure to a metrology equipment for subsequent YE measurement includes:
[0067] The first step is to scan the second semiconductor structure with UV light under normal pressure to obtain the defects on the surface of the second semiconductor structure. This is mainly done by comparing the defects with the surrounding area pattern to obtain the wafer surface defects and thus obtain the linear map of the wafer. The second semiconductor structure is the semiconductor structure after removing the metal body layer that extends beyond the top of the contact hole. Furthermore, the aforementioned surrounding area can be other areas on the wafer without contact holes.
[0068] The second step involves evacuating the chamber of the YE measuring instrument and bombarding the surface of the second semiconductor structure with an electron beam in a vacuum environment. Scattered electrons and secondary electrons from the surface of the second semiconductor structure are collected to obtain defects on the surface of the second semiconductor structure. This is mainly achieved using a scanning electron microscope (SEM). In a vacuum environment, an electron beam is fired through an electron gun. By collecting scattered electrons and secondary electrons from the wafer surface, the morphology and composition of the second semiconductor structure surface are obtained. From the obtained linear map, large voids 70 can be seen. The RGA parameters corresponding to the measuring instrument can actually reflect the actual organic contamination performance of the B&S instrument.
[0069] During the later YE measurement process, when the chamber of the measuring machine is evacuated, the vacuum level inside the chamber of the measuring machine is <10^-7 Torr.
[0070] This application, by performing post-processing YE measurement, can further monitor as many defects as possible in the second semiconductor structure in a timely manner, thereby enabling timely response strategies and further improving work efficiency.
[0071] In this application, by evacuating the chamber of the measurement instrument after forming the metal barrier layer and the metal seed layer, and before forming the metal main body layer, organic contaminants at the bottom of the contact hole can be moved to the sidewall near the top of the contact hole and the surface of the first semiconductor structure (wafer), and the organic contaminants can be aggregated into contaminant clusters, increasing the diameter of the organic contaminants. This results in large-sized void defects in the metal main body layer (conductive plug) that are easy to observe. That is, the void size in the metal main body layer (conductive plug) can be magnified during the formation of the metal main body layer, so that all organic contaminants in the B&S instrument can be monitored in a timely and effective manner during the later YE measurement. Furthermore, the organic contamination monitoring method for the B&S instrument provided in this application does not use the RGA method to monitor organic contamination, thereby avoiding the difficulty of replacing new parts after the relevant parts are damaged in the existing organic contamination monitoring methods for B&S instruments. This breaks through the limitations of the existing monitoring of organic contamination in B&S instruments and increases the feasibility and reliability of monitoring organic contamination in B&S instruments.
[0072] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.
Claims
1. A method of monitoring organic contamination of a B&S machine, characterized by, include: A substrate is provided on which stacked multilayer dielectric layers are formed, and contact holes are formed in the multilayer dielectric layers; A metal barrier layer and a metal seed layer are formed using a B&S machine. The metal barrier layer covers the top dielectric layer and the bottom and side walls of the contact hole, and the metal seed layer covers the metal barrier layer. The first semiconductor structure is transferred to the measuring instrument and the chamber of the measuring instrument is evacuated to allow organic contaminants to move to the side wall near the top of the contact hole and the surface of the first semiconductor structure and accumulate into contaminant clusters. The first semiconductor structure is the semiconductor structure formed after the metal barrier layer and the metal seed layer are formed. A metal body layer is formed, which covers the metal seed layer in the contact hole and fills the remaining space of the contact hole; Remove the metal body layer that extends beyond the top of the contact hole; Perform post-contamination YE measurements to monitor the contamination clusters on the B&S machine in a timely manner.
2. The method of claim 1, wherein the B&S machine is an organic contamination monitoring machine. The step of transferring the first semiconductor structure to the measurement equipment and evacuating the chamber of the measurement equipment is to perform preliminary YE measurement.
3. The method for monitoring organic contamination of B&S machines according to claim 2, characterized in that, The preliminary YE measurement includes: The first semiconductor structure was scanned using UV light under normal pressure. The chamber of the measuring instrument is evacuated, and the surface of the first semiconductor structure is bombarded with an electron beam in a vacuum environment. Scattered electrons and secondary electrons from the surface of the first semiconductor structure are collected to obtain the defects on the surface of the first semiconductor structure.
4. The method for monitoring organic contamination of B&S machines according to claim 1 or 3, characterized in that, During the process of evacuating the chamber of the measuring instrument, the vacuum level inside the chamber of the measuring instrument is <10^-7 Torr.
5. The method for monitoring organic contamination of B&S machines according to claim 1, characterized in that, The metal substrate layer is formed using an electrochemical plating process.
6. The method for monitoring organic contamination of B&S machines according to claim 1, characterized in that, The subsequent YE measurement includes: The second semiconductor structure is scanned using UV light under normal pressure, wherein the second semiconductor structure is the semiconductor structure after removing the metal body layer extending beyond the top of the contact hole; The chamber of the measuring instrument is evacuated, and the surface of the second semiconductor structure is bombarded with an electron beam in a vacuum environment. Scattered electrons and secondary electrons from the surface of the second semiconductor structure are collected to obtain the defects on the surface of the second semiconductor structure.
7. The method for monitoring organic contamination of B&S machines according to claim 6, characterized in that, During the process of evacuating the chamber of the measuring instrument, the vacuum level inside the chamber of the measuring instrument is <10^-7 Torr.
8. The method for monitoring organic contamination of B&S machines according to claim 1, characterized in that, The metal body layer extending beyond the top of the contact hole is removed using a chemical mechanical polishing process.
9. The method for monitoring organic contamination of B&S machines according to claim 1, characterized in that, During the process of evacuating the chamber of the measuring instrument to allow organic contaminants to move to the side wall near the top of the contact hole and the surface of the first semiconductor structure and aggregate into contaminant clusters, the diameter of the contaminant clusters is greater than or equal to 0.1 μm.
10. The method for monitoring organic contamination of B&S machines according to claim 1, characterized in that, The metal barrier layer is formed using physical vapor deposition (PVD); the metal seed layer is formed using physical vapor deposition (PVD).