TWI824656B - Dressing disc and preparation method thereof, chemical mechanical polishing equipment - Google Patents

Abstract

The invention provides a trimming disk, a preparation method thereof, and chemical mechanical polishing equipment, and belongs to the field of semiconductor technology. The preparation method of the trimming disc includes: depositing a carbophilic metal element on the base surface of the trimming disc, causing metal interdiffusion to occur between the carbophilic metal element and the base, and forming a carbophilic metal layer on the base surface; using electroplating Or electroless plating method is used to coat diamond particles on the surface of the carbon-philic metal layer. The technical solution of the present invention can effectively improve the bonding strength between the diamond particles and the dressing disc base, thereby increasing the service life of the dressing disc.

Description

Dressing disc and preparation method thereof, chemical mechanical polishing equipment

The invention belongs to the field of semiconductor technology, and in particular refers to a trimming disk and a preparation method thereof, as well as chemical mechanical polishing equipment.

As the most basic material in the semiconductor field, wafers can be processed into various circuit element structures and become integrated circuit products with specific electrical functions.

With the development of the semiconductor industry, the scale of integrated circuits has also continued to expand, and chip manufacturers have increasingly higher requirements for the quality of substrates. Higher requirements have been put forward for high-quality silicon single crystal polishing pads. During the double-sided polishing process, the polishing pad (Pad) surface will generate a certain amount of Glazing (glazing; smoothing) due to grinding residues. , causing the micropores on the Pad surface to be blocked, reducing the grinding efficiency of the Wafer surface.

It is very necessary to use high-quality chemical mechanical polishing (CMP) dressing discs to repair the Pad surface. Because diamond has the highest hardness and excellent properties, diamond is often used to repair the pad surface. However, because diamond has high interfacial energy and chemical inertness, the bonding performance between the existing dressing disc and the diamond particles on the surface is very poor. At high speeds, Under the action of the huge mechanical shear force caused by rotation, the diamond particles are easily peeled off and fall off, resulting in the current CMP dressing discs having the disadvantages of high cost and short service life.

In view of this, the present invention provides a dressing disc, a preparation method thereof, and chemical mechanical polishing equipment, which can effectively improve the bonding strength between diamond particles and the dressing disc base, thereby increasing the service life of the dressing disc.

In order to solve the above technical problems, the present invention adopts the following technical solutions: In one aspect, embodiments of the present invention provide a method for preparing a dressing disk, including: In some embodiments, the carbophilic metal element is tantalum, titanium, tungsten or hafnium.

In some embodiments, depositing carbophilic metal elements on the surface of the substrate of the trimming disk includes: using a double-glow plasma surface metallurgy DGPSA step to deposit carbophilic metal elements on the surface of the substrate.

In some embodiments, in the DGPSA step, the deposition temperature changes from 400 to 900° C., the deposition pressure is 30 to 40 Pa, and the protective gas is argon.

In some embodiments, after electroplating or chemical plating is used to coat diamond particles on the surface of the carbophilic metal layer, the method further includes: performing an annealing step on the substrate coated with diamond particles.

In some embodiments, in the annealing step, the temperature changes in an equal gradient from 600 to 900°C.

In some embodiments, the substrate is made of 304 stainless steel.

In some embodiments, the thickness of the carbophilic metal layer is 0.8-1.5 μm .

An embodiment of the present invention also provides a trimming disk, which is produced using the above preparation method.

An embodiment of the present invention also provides a chemical mechanical polishing equipment, including the dressing disk as described above.

The beneficial effects of the above technical solutions of the present invention are as follows: According to the preparation method of the dressing disc according to the embodiment of the present invention, carbon-philic metal elements are deposited on the substrate surface of the dressing disc, so that metal interdiffusion occurs between the carbon-philic metal elements and the substrate. A carbophilic metal layer is formed on the surface of the substrate, and the carbophilic metal elements can be tightly combined with the substrate. After that, electroplating or chemical plating is used to coat diamond particles on the surface of the carbophilic metal layer. The bonding performance between the diamond particles and the carbophilic metal layer is better, which can make the bonding performance between the diamond particles and the base of the dressing disc better. The diamond particles It is not easy to peel off and fall off, extending the service life of the trimming disc.

1: Base

2: Carbophilic metal layer

3:Diamond particles

S101-S102: Steps

FIG. 1 is a schematic flowchart of a method for preparing a trimming disk according to an embodiment of the present invention; FIG. 2 is a schematic structural diagram of a trimming disk according to an embodiment of the present invention.

In order to help the review committee understand the technical features, content and advantages of the present invention and the effects it can achieve, the present invention is described in detail below in the form of embodiments with the accompanying drawings and attachments, and the drawings used therein are , its purpose is only for illustration and auxiliary description, and may not represent the actual proportions and precise configurations after implementation of the present invention. Therefore, the proportions and configuration relationships of the attached drawings should not be interpreted or limited to the actual implementation of the present invention. The scope shall be stated first.

In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical" ", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience and simplicity in describing the embodiments of the present invention. The description does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore is not to be construed as a limitation of the invention.

In addition, the terms “first” and “second” are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Thus, features defined as “first” and “second” may explicitly or implicitly include one or more of the described features. In the description of the embodiments of the present invention, "plurality" means two or more than two, unless otherwise explicitly and specifically limited.

In the embodiments of the present invention, unless otherwise expressly stipulated and limited, the terms "installation", "connection", "connection", "fixing" and other terms should be understood in a broad sense. For example, it can be a fixed connection or a removable connection. Disassembly and connection, or integration; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interaction between two elements. For those with ordinary knowledge in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

Embodiments of the present invention provide a dressing disc, a preparation method thereof, and chemical mechanical polishing equipment, which can effectively improve the bonding strength between diamond particles and the dressing disc base, thereby increasing the service life of the dressing disc.

An embodiment of the present invention provides a method for preparing a trimming disk, as shown in Figures 1 and 2, including: S101: Deposit a carbophilic metal element on the substrate surface of the trimming disk, causing metal interdiffusion to occur between the carbophilic metal element and the substrate, and forming a carbophilic metal layer on the substrate surface; S102: Using electroplating or electroless plating methods Diamond particles are coated on the surface of the carbon-philic metal layer.

In this embodiment, a carbon-philic metal element is deposited on the surface of the substrate 1 of the trimming disk, causing metal interdiffusion to occur between the carbon-philic metal element and the substrate 1, and a carbon-philic metal layer 2 is formed on the surface of the substrate 1. The carbon-philic metal element Can be tightly combined with the base 1. After that, electroplating or chemical plating is used to coat diamond particles 3 on the surface of the carbophilic metal layer 2. The diamond particles 3 have better bonding properties with the carbophilic metal layer 2, so that the diamond particles 3 can be combined with the base 1 of the dressing disk. The performance is better, the diamond particles 3 are not easy to peel off and fall off, extending the service life of the dressing disc.

Among them, the mesh number of the diamond particles 3 can be determined as needed. If the polishing pad needs to be finely ground, select diamond particles 3 with a smaller particle size; if the polishing pad needs to be roughly ground, select diamond particles 3 with a larger particle size.

In this embodiment, electroless plating or electroplating is used to coat diamond particles 3 with a required mesh size on the surface of the carbon-philic metal layer 2, so that the diamond particles 3 can be effectively formed on the surface of the carbon-philic metal layer 2. The diamond particles 3 can effectively form certain carbides with the carbophilic metal layer 2, so that the bonding performance between the diamond particles 3 and the substrate 1 is better, extending the service life of the dressing disk; and the diamond particles 3 can be evenly distributed on the surface of the substrate 1 , to achieve excellent grinding effect.

In some embodiments, the carbophilic metal element may be tantalum, titanium, tungsten or hafnium. Of course, the carbon-loving metal element is not limited to tantalum, titanium, tungsten or hafnium, and other metal elements that are easy to combine with carbon can also be used.

In some embodiments, depositing the carbophilic metal element on the substrate surface of the conditioning disk includes: The carbon-philic metal element is deposited on the surface of the substrate using a double-glow plasma surface metallurgy (DGPSA) step.

In this embodiment, a double-glow plasma surface metallurgy step is used to metallize the surface of the substrate, so that metal interdiffusion can occur between the deposited metal and the substrate, and metallurgical bonding is performed so that the carbophilic metal elements and the substrate are closely combined. .

In some embodiments, in the DGPSA step, the deposition temperature changes from 400 to 900° C., the deposition pressure is 30 to 40 Pa, and the protective gas is argon.

That is, the deposition temperature changes in an equal gradient within the range of 400-900°C. For example, the deposition temperature is maintained at 400°C for a period of time, then at 500°C for a period of time, then at 600°C for a period of time, at 700°C for a period of time, and at 800℃ for a period of time, and finally keep at 900℃ for a period of time. The time to keep at a certain temperature value or a certain temperature range can be set as needed.

In some embodiments, after electroplating or chemical plating is used to coat diamond particles on the surface of the carbophilic metal layer, the method further includes: performing an annealing step on the substrate coated with diamond particles. The purpose of the annealing step is to enable carbides to be formed between the diamond particles and the carbophilic metal layer, which is conducive to better bonding performance between the diamond particles and the substrate.

In some embodiments, in the annealing step, the step temperature changes in an equal gradient from 600 to 900°C. That is, the step temperature changes in an equal gradient within the range of 600-900°C, such as keeping it at 600°C for a period of time, then keeping it at 700°C for a period of time, then keeping it at 800°C for a period of time, and finally keeping it at 900°C for a period of time, and then keeping it at a certain temperature. A temperature value or a time in a certain temperature range can be set as needed.

In some embodiments, the substrate is made of 304 stainless steel. Using 304 stainless steel as the base is beneficial to enhancing the bonding force between the diamond particles and the dressing disc, and extending the grinding life of the dressing disc. Of course, the base is not limited to 304 stainless steel, but can also be made of other materials with a certain hardness.

In some embodiments, the thickness of the carbophilic metal layer is 0.8-1.5 μm , which allows the carbophilic metal layer to effectively form certain carbides with the diamond particles, so that the bonding performance between the diamond particles and the substrate is better.

In a specific embodiment, when Ti is used as the carbophilic metal layer, the deposition of the carbophilic metal element on the substrate surface of the trimming disk includes: using a double-glow plasma surface metallurgy DGPSA step to deposit a Ti layer on the substrate surface.

Specifically, in this DGPSM step, a filamentous target is used as the source, the deposition temperature is 700-900°C, the deposition pressure is 30-40Pa, and the protective gas is argon. The filament target can be prepared by uniformly fixing Ti wire with a purity of 99.999% on a stainless steel plate. The size of the Ti wire is Φ3.5mm×20mm, and the size of the stainless steel plate is 55mm×55mm×3.0mm. The thickness of the carbophilic metal layer is controlled to 0.8-1.5 μm by controlling the deposition time. The wire-shaped Ti target can form a higher charge density at the tip of the Ti wire and improve the sputtering efficiency of Ti atoms.

An embodiment of the present invention also provides a trimming disk, which is produced using the above preparation method.

The cross-sectional view of the dressing disk of this embodiment is shown in Figure 2. The dressing disk includes a substrate 1, a carbon-philic metal layer 2 located on the surface of the substrate 1, and diamond particles 3 located on the surface of the carbon-philic metal layer 2.

In this embodiment, carbophilic metal elements are deposited on the substrate surface of the trimming disk, causing metal interdiffusion to occur between the carbophilic metal elements and the substrate. A carbophilic metal layer is formed on the substrate surface, and the carbophilic metal elements can closely interact with the substrate. The base is combined. After that, electroplating or electroless plating is used to coat the carbon-loving metal The surface of the layer is coated with diamond particles. The bonding performance between the diamond particles and the carbophilic metal layer is better, which can make the bonding performance between the diamond particles and the base of the dressing disc better. The diamond particles are not easy to peel off and fall off, which increases the service life of the dressing disc. .

An embodiment of the present invention also provides a chemical mechanical polishing equipment, including the dressing disk as described above. In the dressing disk of this embodiment, the bonding performance of the diamond particles and the carbophilic metal layer is better, which can make the bonding performance of the diamond particles and the base of the dressing disk better, and the diamond particles are not easy to peel off, which improves the service life of the dressing disk. .

The above are only preferred embodiments of the present invention and are not intended to limit the implementation scope of the present invention. If the present invention is modified or equivalently substituted without departing from the spirit and scope of the present invention, the protection shall be covered by the patent scope of the present invention. within the range.

1: Base

2: Carbophilic metal layer

3:Diamond particles

Claims (8)

A method for preparing a trimming disc, including: depositing a carbon-philic metal element on the surface of a trimming disc base, causing metal interdiffusion to occur between the carbon-philic metal element and the substrate, and forming a carbon-philic metal layer on the surface of the substrate; utilizing The electroplating or electroless plating method is used to coat diamond particles on the surface of the carbophilic metal layer; the deposition of carbophilic metal elements on the substrate surface of the trimming disk includes: using a double glow plasma surface metallurgy (DGPSA) step to deposit on the substrate. Carbophilic metal elements are deposited on the surface; in this DGPSA step, the deposition temperature changes from 400 to 900°C in equal gradients, the deposition pressure is 30-40 Pa, and the protective gas is argon. The method for preparing a trimming disk according to claim 1, wherein the carbophilic metal element is tantalum, titanium, tungsten or hafnium. The method for preparing a dressing disk as claimed in claim 1 or 2, wherein, after coating diamond particles on the surface of the carbophilic metal layer using an electroplating or electroless plating method, the method further includes: coating the surface of the carbophilic metal layer with diamond particles. The substrate undergoes an annealing step. The preparation method of the trimming disk as described in claim 3, wherein in the annealing step, the temperature changes in an equal gradient from 600 to 900°C. The preparation method of the dressing disk as described in claim 1, wherein the base is made of 304 stainless steel. The method for preparing a trimming disk as claimed in claim 1, wherein the thickness of the carbophilic metal layer is 0.8-1.5 μm . A trimming disk is produced by the preparation method of the trimming disk described in any one of claims 1 to 6. A chemical mechanical polishing equipment, including the dressing disk as described in claim 7.