Patent Application
20240217055
This application claims the benefit of priority of Chinese patent application with the application number 202210485451.3, entitled “Chemical Mechanical Polishing Process Method and Device”, filed with the China National Intellectual Property Administration on May 6, 2022, the contents of which are incorporated herein by reference in its entirety.
Embodiments of the present disclosure relate to the technical field of semiconductor manufacturing, and in particular, to a chemical mechanical polishing process method and device.
The chemical mechanical polishing (CMP) process is one of the very critical processes in the semiconductor manufacturing process, can be used for the preparation of conductive plugs in semiconductor structures.
Taking the metal tungsten CMP process as an example, in the preparation process of the tungsten connection filling holes, a deep well groove is generally formed in the oxide layer, and then metal tungsten is filled in the groove. At this time, metal tungsten is also deposited on the surface; the metal tungsten located on the surface of the oxide layer needs to be removed by a CMP process, so only the metal tungsten in the groove is retained as a metal connection. The existing CMP process generally uses two polishing discs. By using different polishing liquids, the metal tungsten in the groove can protrude from the surface of the oxide layer, but the utilization rate of the CMP machine is not high.
In order to improve the utilization rate of a CMP machine, a CMP process on a single polishing disc is proposed in the existing techniques. However, the CMP process on a single polishing disc in existing techniques cannot make the metal tungsten in the groove protrude from the surface of the oxide layer, which may result in an ineffective connection between the metal tungsten and the metal conductive layer, reducing the product yield.
The embodiments of the present disclosure provide a chemical mechanical polishing process method and device, which can improve the yield of existing CMP process using single polishing disc.
In a first aspect, an embodiment of the present disclosure provides a chemical mechanical polishing process method, including:
In a second aspect, embodiments of the present disclosure provide a chemical mechanical polishing device, including:
The chemical mechanical polishing process method and device provided in the embodiments of the present disclosure propose a novel first polishing liquid and a second polishing liquid. For the substrate on which the dielectric layer and the conductive layer are formed, the first polishing liquid and the second polishing liquid are firstly used. The mixed polishing liquid of the second polishing liquid performs chemical mechanical polishing on the substrate placed on the polishing disc to remove the conductive layer covered on the upper surface of the intermediate layer; chemical-mechanical polishing is performed on the substrate placed on the polishing disc with the second polishing liquid to remove part of the dielectric layer, so that the upper surface of the dielectric layer is lower than the top surface of the conductive layer filling in the groove, so as to ensure that the conductive layer can protrude from the surface of the dielectric layer, which improves the product yield of the CMP process on a single polishing disc.
It should be understood that the above general description and the following detailed description are only exemplary and cannot limit the present disclosure.
By describing its exemplary embodiments in detail with reference to the accompanying drawings, the above and other objectives, features and advantages of the present disclosure will become more apparent.
In order to achieve the goals, technical solutions and meet advantages of the embodiments of the present disclosure with more clarity, the technical features in the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are some, but not all, details of the present disclosure. The embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present disclosure. Furthermore, although the disclosures in this disclosure are presented in terms of illustrative example or instances, it should be understood that various aspects of this disclosure may also constitute a complete embodiment in isolation.
It should be noted that the brief description of terms in the present disclosure is only to facilitate the understanding of the embodiments described below, rather than intended to limit the embodiments of the present disclosure. Unless otherwise specified, these terms are to be understood according to their ordinary and ordinary meanings.
The terms “first”, “second” and the like in the description and claims of the present disclosure and the above drawings are used to distinguish similar or similar objects or entities, and are not necessarily meant to limit a specific order or sequence. unless otherwise noted. It is to be understood that the terms so used are interchangeable under appropriate circumstances, eg, can be implemented in an order other than those presented in the illustrations or descriptions of embodiments in accordance with the present disclosure.
Furthermore, the terms “comprising” and “having” and any variations thereof, are intended to cover but not exclusively include, for example, a product or device incorporating a series of components is not necessarily limited to those explicitly listed, but may include No other components are expressly listed or inherent to these products or devices.
The term “module” used in the embodiments of the present disclosure refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware or/and software codes capable of performing the functions associated with the elements.
Optionally, the embodiments of the present disclosure relate to a dynamic random access memory (Dynamic Random Access Memory, DRAM for short) process technology, which can be applied to a tungsten (W) CMP process in DRAM production.
In the preparation process of the tungsten connection filling hole, a deep-well groove is generally formed in the oxide layer, and then metal tungsten is filled in the groove. During the filling process, the surface of the oxide layer is also deposited with metal like tungsten; at this time, the metal tungsten located on the surface of the oxide layer needs to be removed by the CMP process, and only the metal tungsten in the groove is retained as a metal connection.
A traditional CMP process generally uses two polishing discs. Referring to
As shown in
Step 1. Provide the substrate 10 with the dielectric layer 20 and the conductive layer 30 formed thereon, wherein the dielectric layer 20 has a groove and the conductive layer 30 covers the upper surface of the dielectric layer 20 and fills the groove.
The conductive layer 30 includes a tungsten (W) layer 31 on a titanium nitride (TiN) layer 32, and the titanium nitride layer 32 is located between the dielectric layer 20 and the tungsten layer 31.
In some embodiments, the dielectric layer 20 is oxide.
Step 2: A part of W layer is removed from the polishing disc 1 using the a polishing liquid A (which has a polishing rate of W>polishing rate of oxide).
Step 3: Use the B polishing liquid (which has a polishing rate of the oxide>the polishing rate of W) to remove a part of the titanium nitride and part of the oxide by the polishing disc 2, so as to realize the W protruding structure 312 on the top of the tungsten plug 311 to ensure that the W at a better a contact and connection between metal layers.
Among them, since the raw materials contained in the A polishing liquid and the B polishing liquid are quite different, and the A polishing liquid and the B polishing liquid will react during the mixing process, the by-products formed are difficult to remove, so the A polishing liquid can only be used alone. For the polishing disc 1, the B polishing fluid can only act on the polishing disc 2 alone, and the W protruding structure can be formed well through the polishing process of the double polishing discs. However, in the mass production line, more consumables and machine tools are required, so the utilization rate of the machine is low.
Therefore, in the above-mentioned CMP process on double polishing discs, although the W protruding structure can be realized, the utilization rate of the CMP machine is not high.
In order to improve the utilization rate of the CMP machine, a CMP process on a single polishing disc has been proposed in some solutions. However, in the existing CMP process on a single polishing disc, using a traditional single polishing liquid, it is impossible to achieve a polishing rate of oxide polishing rate>W, so in the process result, the W is recessed, and the W protruding structure cannot be formed.
For a better understanding of the embodiment of the present disclosure, refer to
As shown in
Step 1. Providing the substrate 10 with the dielectric layer 20 and the conductive layer 30 formed thereon, wherein the dielectric layer 20 has a groove, and the conductive layer 30 covers the upper surface of the dielectric layer 20 and fills the groove.
The conductive layer 30 includes a tungsten (W) layer 31 on a titanium nitride (TiN) layer 32, and the titanium nitride layer 32 is located between the dielectric layer 20 and the tungsten layer 31.
In some embodiments, the dielectric layer 20 is oxide.
In step 2, a part of W and titanium nitride is removed from the polishing disc using a polishing liquid (which has polishing rate of W>polishing rate of oxide).
Since the polishing rate of the above-mentioned polishing liquid for W is greater than the polishing rate of the oxide, the top of the tungsten plug 311 will have a recess 313 in the process result, and the W protruding structure cannot be formed. Such a process result increases the processing difficulty of the subsequent process, which may result in an ineffective connection between the W and the metal layer, which seriously affects the yield of the product.
In addition, if the above-mentioned CMP process on a single polishing disc uses the above-mentioned A polishing liquid and B polishing liquid to carry out two polishings successively, even after the first polishing, the surface of the substrate 10 is difficult to be completely cleaned. Because the difference between A polishing liquid and B polishing liquid is large, during the second polishing, the unwashed A polishing liquid and B polishing liquid will react, and the formed by-products are difficult to remove, which will seriously affect the production yield.
Faced with the above technical problems, the embodiments of the present disclosure provide a chemical mechanical polishing process method. By proposing a new type of first polishing liquid and a second polishing liquid, for the substrate containing the dielectric layer and the conductive layer are formed, first use the mixture of the first polishing liquid and the second polishing liquid to performs chemical mechanical polishing on the substrate placed on the polishing disc, to remove the conductive layer covering on the upper surface of the dielectric layer; after rinsing, chemical mechanical polishing is performed on the substrate placed on the polishing disc with the second polishing liquid to remove a part of the dielectric layer, so that the upper surface of the dielectric layer is made lower than the upper surface of the conductive layer filling the groove, so as to ensure that the conductive layer in the groove protrude from the surface of the dielectric layer, which improves the product yield of the CMP process on a single polishing disc.
Referring to
S301. Provide a substrate having a dielectric layer and a conductive layer, the dielectric layer has a groove, and the conductive layer covers the upper surface of the dielectric layer and fills the groove.
The conductive layer includes a tungsten layer.
S302, performing CMP on the substrate placed on the polishing disc using a mixture polishing liquid of the first polishing liquid and the second polishing liquid, to remove the conductive layer on the upper surface of the dielectric layer.
Herein, the polishing rate of the mixed polishing liquid on the conductive layer is greater than the polishing rate on the dielectric layer.
S303, rinsing the substrate placed on the polishing disc with a cleaning liquid to remove the mixed polishing liquid remaining on the substrate.
S304, performing CMP on the substrate placed on the polishing disc by using the second polishing liquid, to remove a part of the dielectric layer, so the upper surface of the dielectric layer is lower than the upper surface of the conductive layer filled inside the groove.
Herein, the polishing rate of the second polishing liquid for the conductive layer is lower than the polishing rate for the dielectric layer.
For a better understanding of the embodiments of the present disclosure, refer to
The CMP process is implemented on a single polishing disc.
In some embodiments of the present disclosure, the above-mentioned CMP process includes:
Step 1. Providing the substrate 10 having the dielectric layer 20 and the conductive layer 30 formed thereon, wherein the dielectric layer 20 has grooves, and the conductive layer 30 covers the upper surface of the dielectric layer 20 and fills the grooves.
Optionally, the substrate 10 may be a substrate, such as a silicon substrate, a sapphire substrate, or a gallium nitride substrate, and the like.
In some embodiments, functional devices that require electrical extraction, such as MOS devices, etc., are formed in the substrate 10.
In some embodiments, the dielectric layer 20 is an oxide (Ox), such as silicon oxide (SiOx) or the like. In addition, the dielectric layer 20 may also be silicon nitride (SiN) or the like.
In some embodiments, the dielectric layer 20 may be formed on the front surface of the substrate 10 by a physical vapor deposition process or a chemical vapor deposition process.
In some embodiments, the above-mentioned grooves may be formed in the dielectric layer 20 using photolithography and etching processes. The number of grooves formed in the dielectric layer 20 can be set according to actual needs. For example, the number of grooves formed in the dielectric layer 20 may be plural.
In some embodiments, the conductive layer 30 includes a tungsten (W) layer 31 and a titanium nitride (TiN) layer 32 located between the dielectric layer 20 and the tungsten layer 31. Optionally, the titanium nitride layer 32 is located on the sidewall and bottom of an above-mentioned groove, and extends from the above-mentioned groove to the surface of the dielectric layer 20 and covers the upper surface of the dielectric layer 20; the tungsten layer 31 is located on the titanium nitride layer 32. The upper surface of the tungsten layer 31 fills the groove and covers the surface of the titanium nitride layer 32.
Optionally, the tungsten layer 31 may be formed by a physical vapor deposition process or a chemical vapor deposition process.
In other embodiments, the conductive layer 30 may further include any other metal layer that can form a conductive metal plug, such as at least one of a copper layer, a tin layer, a titanium layer, a nickel layer, a silver layer or a gold layer.
Step 2: performing CMP on the substrate 10 placed on the polishing disc using a mixed polishing liquid of the first polishing liquid and the second polishing liquid to remove part of the conductive layer 30 covering the surface of the dielectric layer 20.
Herein, the polishing rate of the above-mentioned mixed polishing liquid for the tungsten in the conductive layer 30 is higher than that for the oxide in the dielectric layer 20.
Herein, the basic composition and concentration of the first polishing liquid and the second polishing liquid are similar, so that the mixed polishing liquid of the first polishing liquid and the second polishing liquid can be mixed and polish on the same polishing disc.
It should be noted that, in the chemical mechanical polishing process, the device to be polished is fixed on a polishing head, and the polishing head presses the device to be ground on a polishing disc located on the upper surface of a polishing platform, and the polishing liquid supply system is feeding the above polishing head. When the polishing liquid is sprayed on the disc, the above-mentioned polishing platform drives the above-mentioned polishing disc to rotate, and the above-mentioned polishing head drives the above-mentioned device to be ground to rotate in the opposite direction to the rotation direction of the above-mentioned polishing disc, so as to grind the above-mentioned device to be ground.
In some embodiments, in the process of chemical mechanical polishing of the substrate 10 using the above mixed polishing liquid, a preset chemical mechanical polishing endpoint detection program is used to detect whether the titanium nitride layer 32 has been polished; When the titanium nitride layer 32 is formed, the chemical mechanical polishing of the substrate with the mixed polishing liquid is stopped.
In some embodiments, the above-mentioned chemical mechanical polishing endpoint detection program may be a friction force endpoint detection program.
Among them, the end point detection procedure based on friction force is used to judge the interface of polishing by detecting the difference in friction coefficient when the material and the polishing pad rub against each other, and the specific implementation methods include indirect measurement method and direct measurement method. The direct measurement method is to directly measure the polishing friction force to realize the endpoint detection. For example, the frictional force between the material to be ground and the polishing pad will produce resistance to the swing of the polishing head, and a force piezoelectric sensor is used to monitor the lateral force on the polishing head. When the material transmission of the polishing interface changes, the lateral friction force will change, and end-pint detection force.
In the indirect method, the end point detection method is used to detect the current transformation of the polishing motor caused by the change of polishing friction. In order to maintain the swing of the polishing head and the stability of the rotating station, the current intensity of the driving motor of the polishing head will change with the rotation resistance of the polishing head and the rotation torque of the polishing disc. Therefore, the end point of polishing can be determined by real-time measurement of parameters such as the driving current of the motor and the motor resistance of the polishing head.
In some other embodiments, the above-mentioned chemical mechanical polishing endpoint detection program may also be an optical-endpoint detection program, an electromagnetic coupling endpoint detection program, an electrochemical endpoint detection program, a thermal imaging endpoint detection program, etc., which are not performed in the embodiments of the present disclosure.
Step 3: Rinsing the substrate 10 placed on the polishing disc with a cleaning liquid to remove the mixed polishing liquid remaining on the substrate 10.
In some embodiments, the substrate 10 placed on the polishing disc may be rinsed with deionized water (DIW) to remove residual mixed polishing liquid on the substrate 10 and avoid excessive polishing of W in the groove.
Step 4. Using the second polishing liquid to perform chemical mechanical polishing on the substrate 10 placed on the polishing disc to remove part of the dielectric layer 20, so that the upper surface of the dielectric layer 20 is lower than the upper surface of the conductive layer 30 filled in the groove, a W protrusion structure 312 is formed on the top of the tungsten plug 311.
Herein, the polishing rate of the oxide in the dielectric layer 20 by the second polishing liquid is higher than the polishing rate of W in the conductive layer 30.
It can be understood that, since the polishing rate of oxides by the second polishing liquid is greater than that of W, after chemical mechanical polishing of the substrate 10 placed on the polishing disc with the second polishing liquid for a period of time, the intermediate layer on the upper surface of 20 will be lower than the top surface of the tungsten plug 311 filling the groove.
In some embodiments, a polishing thickness can be set, and then the polishing can be stopped after the oxide of the thickness is polished with the second polishing liquid.
Optionally, the range of the above polishing thickness may be 40 nm to 200 nm.
In the chemical mechanical polishing process method provided in the embodiments of the present disclosure, after providing the substrate on which the dielectric layer and the conductive layer are formed, a mixed polishing liquid of the first polishing liquid and the second polishing liquid is used to rub the substrate placed on the polishing disc first. Carry out chemical mechanical polishing to remove the conductive layer covered on the upper surface of the dielectric layer; then use the cleaning solution to rinse the substrate placed on the polishing disc, and then use the second polishing fluid to perform chemical mechanical polishing on the substrate placed on the polishing disc to remove part of the dielectric layer, so that the upper surface of the dielectric layer is lower than the upper surface of the conductive layer filled in the groove, so as to ensure that the conductive layer in the groove can protrude from the surface of the dielectric layer, which improves the performance on the single disc polishing yield of the CMP process.
In the embodiments of the present disclosure, a novel first polishing liquid and a second polishing liquid are proposed. The basic composition and concentration of the first polishing liquid and the second polishing liquid are similar, so that the two polishing liquids can be mixed and ground in the same polishing disc without chemical reaction to generate insoluble substances.
In some embodiments, the first polishing liquid can be obtained by adding an appropriate amount of catalyst and stabilizer on the basis of the second polishing liquid to increase the polishing rate of W, but the polishing rate of oxides is kept basically constant.
In some embodiments of the present disclosure, if the second polishing liquid is used as the base liquid, the first polishing liquid includes the basic liquid and the above-mentioned catalyst and stabilizer.
Optionally, the above-mentioned basic fluid includes solid abrasive particles, hydrogen peroxide and water.
Wherein, the above-mentioned solid abrasive particles are sol-type silica or ceria; the mass percentage of the above-mentioned hydrogen peroxide in the basic liquid is 1% to 3%; the mass percentage of the above-mentioned water in the basic liquid is 50% to 95%; the pH value of the basic liquid is 1-3.
Optionally, the solid content of the first polishing liquid and the second polishing liquid are the same, and the solid content is 8% to 14%.
Optionally, the average particle size of the solid abrasive particles in the first polishing liquid and the second polishing liquid is 100 nm to 140 nm.
For a better understanding of the embodiments of the present disclosure, refer to Table 1, which is a comparison table of components of the first polishing liquid and the second polishing liquid.
Optionally, the above-mentioned catalyst is soluble iron, such as iron nitrate or the like. In the hydrogen peroxide (H2O2) environment, the W surface is easily oxidized, making the W surface softer and easier to remove.
Optionally, the mass percentage of the above catalyst in the first polishing liquid is 0.1% to 10%.
Optionally, the above-mentioned stabilizer is an organic acid and its salt, such as ammonium persulfate and the like.
Optionally, the mass percentage of the above stabilizer in the first polishing liquid is 0.05% to 1%.
For a better understanding of the embodiment of the present disclosure, refer to
In
As can be seen from
For a better understanding of the embodiments of the present disclosure, refer to
As can be seen from
The chemical mechanical polishing process method provided in the embodiment of the present disclosure can realize the W protruding structure on a single polishing disc by preparing two new types of polishing liquids, which can improve the utilization rate of the machine while ensuring the yield of the product.
Based on the contents described in the above embodiments, a chemical mechanical polishing device is also provided in the embodiments of the present disclosure. Referring to
Optionally, the polishing liquid supply assembly 64 includes a first polishing liquid supply source 6411, a second polishing fluid supply source 6412, a first infusion pipe 6421, a second infusion pipe 6422, a first spray head 6431 and a second spray head 6432; wherein, one end of the first infusion pipe 6421 is connected with the first polishing liquid supply source 6411, and the other end is connected with the first nozzle 6431, which is located above the polishing pad 62; one end of the second liquid infusion pipe 6422 is connected with the second polishing liquid supply source 6412, and the other end is connected with the second nozzle 6432, which is located above the polishing pad 62.
In a feasible embodiment, the first polishing liquid supply source 6411 is used to provide the first polishing liquid, and the second polishing liquid supply source 6412 is used to provide the second polishing liquid.
Alternatively, the first polishing liquid supply source 6411 is used to provide a mixture of the first polishing liquid and the second polishing liquid, and the second polishing liquid supply source 6412 is used to provide the second polishing liquid.
The control assembly 65 is connected to the polishing liquid supply assembly 64 and is used for adjusting the type of polishing liquid and the flow rate of the polishing liquid provided by the polishing liquid supply assembly 64 into the polishing pad 62.
The cleaning assembly 66 is used to provide cleaning liquid to the surface of the polishing disc.
In a feasible embodiment, the control module 65 is connected to the first polishing liquid supply source 6411 and the second polishing liquid supply source 6412.
The control module 65 is connected to the cleaning component 66 for providing cleaning liquid to the surface of the polishing pad 62 after the first polishing is completed, so as to remove the mixed polishing liquid remaining on the polishing pad 62.
The control module 65 is further configured to control the second liquid supply source 6412 to provide the second polishing liquid to the surface of the polishing pad 62 during the second polishing process.
In some embodiments of the present disclosure, a dielectric layer and a conductive layer are formed on the substrate to be polished. The dielectric layer has grooves, and the conductive layer covers the upper surface of the dielectric layer and fills the grooves. The conductive layer includes a tungsten (W) layer and a titanium nitride layer, and the titanium nitride layer is located between the dielectric layer and the tungsten layer. Optionally, the titanium nitride layer is located on the sidewall and bottom of the above-mentioned grooves, and extends from the above-mentioned grooves to the surface of the dielectric layer, and covers the upper surface of the dielectric layer; the tungsten layer is located on the upper surface of the titanium nitride layer, and the tungsten layer fills the grooves and covers the surface located on the titanium nitride layer.
In some embodiments, the dielectric layer is an oxide, such as silicon oxide (SiOx) or the like.
In some embodiments, during the first polishing process, the control module 65 can control the first polishing supply source 6411 to provide a mixed polishing liquid of the first polishing liquid and the second polishing liquid to the surface of the polishing pad 62; or, the control module 65 can also control the first polishing supply source 6411 to provide the first polishing liquid to the surface of the polishing pad 62 at a first flow rate, and control the second polishing supply source 6412 to provide the second polishing liquid to the surface of the polishing pad 62 at a second flow rate.
Among them, since the polishing rate of the above-mentioned mixed polishing liquid of the first polishing liquid and the second polishing liquid on the tungsten in the conductive layer is greater than the polishing rate on the oxide in the dielectric layer, therefore, in the first polishing process, it is possible to remove the tungsten in the conductive layer. Part of the conductive layer on the surface of the dielectric layer.
In some embodiments, the above chemical mechanical polishing device further includes a detection device for detecting whether the titanium nitride layer has been polished by using a preset chemical mechanical polishing endpoint detection program during the first polishing process; When polishing to the titanium nitride layer, stop the first polishing.
In some embodiments, the above-mentioned chemical mechanical polishing endpoint detection program may be a friction force—endpoint detection program.
In some other embodiments, the above-mentioned chemical mechanical polishing endpoint detection program may also be an optical—endpoint detection program, an electromagnetic coupling endpoint detection program, an electrochemical endpoint detection program, a thermal imaging endpoint detection program, etc., which are not performed in the embodiments of the present disclosure. limit.
In some embodiments, after the first polishing is stopped, the control module 65 can control the cleaning component 66 to provide cleaning liquid to the surface of the polishing disc, so as to remove the mixed polishing liquid remaining on the substrate.
In some embodiments, deionized water (DIW) can be used to rinse the substrate placed on the polishing disc to avoid over-polishing the W in the grooves.
In some embodiments, after the substrate is rinsed, the second polishing can be started. During the second polishing process, the control module 65 can control the second polishing supply source 6412 to provide the second polishing liquid to the surface of the polishing pad 62.
It can be understood that since the polishing rate of oxides by the second polishing liquid is greater than that of W, therefore, after using the second polishing liquid to perform chemical mechanical polishing on the substrate placed on the polishing disc for a period of time, the dielectric layer has an upper surface will be lower than the top surface of the tungsten plugs filled in the grooves.
In some embodiments, a polishing thickness can be set, and then the polishing can be stopped after the oxide of the thickness is polished with the second polishing liquid.
Optionally, the range of the above polished thickness may be 40 nm to 200 nm.
In some embodiments, the first polishing liquid can be obtained by adding an appropriate amount of catalyst and stabilizer on the basis of the second polishing liquid to increase the polishing rate of W, but the polishing rate of oxides is basically constant.
In some embodiments of the present disclosure, if the second polishing liquid is used as the basic liquid, the first polishing liquid includes the basic liquid and the above-mentioned catalyst and stabilizer.
Optionally, the above-mentioned basic liquid includes solid abrasive particles, hydrogen peroxide and water.
Herein, the above-mentioned solid abrasive particles are sol-type silica or ceria; the mass percentage of the above-mentioned hydrogen peroxide in the basic liquid is 1% to 3%; the mass percentage of the above-mentioned water in the basic liquid is 50% to 95%; the pH value of the basic liquid is 1-3.
Optionally, the solid content of the first polishing liquid and the second polishing liquid are the same, and the solid content is 8% to 14%.
Optionally, the average particle size of the solid abrasive particles in the first polishing liquid and the second polishing liquid is 100 nm to 140 nm.
Optionally, the above-mentioned catalyst is soluble iron, such as iron nitrate or the like. In the hydrogen peroxide (H2O2) environment, the W surface is easily oxidized, making the W surface softer and easier to remove.
Optionally, the mass percentage of the above catalyst in the first polishing liquid is 0.1% to 10%.
Optionally, the above-mentioned stabilizer is an organic acid and its salt, such as ammonium persulfate and the like.
Optionally, the mass percentage of the above stabilizer in the first polishing liquid is 0.05% to 10%.
In addition, considering that the polishing liquid used in the single-disk polishing process for the first polishing (for the conductive layer) and the second polishing (for the dielectric layer) should be as similar as possible, otherwise the polishing liquid used is very different. On the one hand, The two polishing slurries may react. On the other hand, during the polishing transition, the first polishing (for the conductive layer) cannot be quickly transferred to the second polishing (for the dielectric layer), resulting in excessive polishing of the conductive layer, and from the perspective of cost optimization, in some embodiments of the present disclosure, when polishing the conductive layer covered on the upper surface of the dielectric layer, the mixed polishing liquid of the first polishing liquid and the second polishing liquid is used; when polishing, the above-mentioned second polishing liquid is used. And in some embodiments of the present disclosure, when used in a mixed polishing liquid of the first polishing liquid and the second polishing liquid, the mass ration of the first polishing liquid and the second polishing liquid may be 1:1 to 1:4, when polishing the conductive layer covered on the upper surface of the dielectric layer, considering that the polishing selection ratio of the polishing liquid to the conductive layer and the dielectric layer is as large as possible, the mass ratio of the first polishing liquid and the second polishing liquid is preferably 1:1.
It can be understood that the chemical mechanical polishing device provided in the embodiment of the present disclosure can switch the traditional 2×2 production mode of the machine to the 4×1 mode by using a single polishing disc process, thereby greatly improving the utilization rate of the machines and saving production costs. Among them, the above 2×2 production mode means that the machine adopts 2 polishing discs, each disc adopts different polishing processes, and can polish two wafers at the same time; the above 4×1 mode means that the machine uses 1 polishing disc and the polishing disk can polish 4 wafers at the same time.
The chemical mechanical polishing device provided in the embodiment of the present disclosure can realize the W protruding structure on a single polishing disc by using two new types of polishing liquids, which can improve the utilization rate of the machine while ensuring the yield of the product.
In the several embodiments provided in the present disclosure, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the device embodiments described above are only illustrative. For example, the division of the modules is only a logical function division. In actual implementation, there may be other division methods. For example, multiple modules may be combined or integrated. to another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or modules, and may be in electrical, mechanical or other forms.
The modules described as separate components may or may not be physically separated, and components shown as modules may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution in this embodiment.
Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, but not to limit them; although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: the technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the embodiments of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202210485451.3 | May 2022 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2022/092954 | 5/16/2022 | WO |
