A pretreatment method for the AlN bonding interface

Abstract

The present invention provides a pretreatment method for an AlN bonding interface, which is used to pretreat the bonding interfaces of an AlN material layer with a substrate and a metal material in a semiconductor device. The metal material is embedded in the substrate and has a flush surface. The pretreatment method includes: at a preset temperature, introducing NH3 onto the surfaces of the substrate and the metal material placed in a deposition chamber to remove metal oxides on the surface of the metal material; continuously introducing a Si source gas onto the surfaces of the substrate and the metal material for a preset duration to pretreat the bonding interface; and depositing an AlN material on the bonding interface to form an AlN layer, and successively depositing other preset materials on the AlN layer to form a multi-layer semiconductor structure.

Description

Technical Field

[0001] The present invention relates to a semiconductor process treatment method, and particularly to a pretreatment method for an AlN bonding interface. Background Art

[0002] With the continuous improvement of chip integration, the size of components has been gradually further reduced, resulting in a decrease in the area of conductive structures such as copper electrodes in the semiconductor structure. This in turn causes an increase in the local current density, leading to an enhanced electromigration ability of local materials.

[0003] At the same time, the dielectric layers in semiconductor devices are usually made of materials with low or ultra-low dielectric constants, which may contain multiple pores. Substance atoms between layers, such as Al atoms, can easily penetrate and enter these pores in the dielectric layers, reducing the electrical isolation performance of the dielectric layers and causing current leakage, resulting in the functional failure of the dielectric layers.

[0004] To overcome the above-mentioned defects existing in the prior art, there is an urgent need in the art for a pretreatment method for an AlN bonding interface, which is used to pre-treat the bonding interface of AlN materials during semiconductor preparation by introducing a silicon source gas into the bonding interface of AlN materials, thereby improving the pore problem in the dielectric layer, enhancing the electrical isolation performance of the dielectric layer, and at the same time being able to optimize the bonding strength between the metal material and the AlN material, and enhancing the reliable performance of the semiconductor device structure. Summary of the Invention

[0005] The following gives a brief overview of one or more aspects to provide a basic understanding of these aspects. This overview is not an exhaustive survey of all contemplated aspects, and is neither intended to identify key or decisive elements of all aspects nor to attempt to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that follows.

[0006] To overcome the above-mentioned defects existing in the prior art, the present invention provides a pretreatment method for an AlN bonding interface, which is used to pre-treat the bonding interface between the AlN material layer and the substrate and the metal material in a semiconductor device. The metal material is embedded in the substrate and has a flush surface. The pretreatment method includes: at a preset temperature, introducing NH3 onto the surfaces of the substrate and the metal material placed in the deposition chamber to remove metal oxides on the surface of the metal material; continuously introducing a Si source gas onto the surfaces of the substrate and the metal material for a preset duration to pre-treat the bonding interface; and depositing an AlN material on the bonding interface to form an AlN layer, and sequentially depositing other preset materials on the AlN layer to form a multi-layer semiconductor structure.

[0007] In one embodiment, preferably, the pretreatment method for the AlN bonding interface provided by the present invention further includes: applying a radio frequency power supply in the deposition chamber before the reaction starts, so that all gases react in the form of plasma, and the power range of the radio frequency power supply is 250W - 750W.

[0008] In one embodiment, preferably, in the pretreatment method for the AlN bonding interface provided by the present invention, the range of the preset duration is 15s - 45s.

[0009] In one embodiment, preferably, in the pretreatment method for the AlN bonding interface provided by the present invention, the preset temperature is 250°C - 350°C.

[0010] In one embodiment, preferably, in the pretreatment method for the AlN bonding interface provided by the present invention, continuously introducing a Si source gas to the surface of the substrate and the metal material within the preset duration to pretreat the bonding interface includes: performing the step of introducing the Si source gas to pretreat the bonding interface by using the PECVD process.

[0011] In one embodiment, preferably, in the pretreatment method for the AlN bonding interface provided by the present invention, the Si source gas includes TSA gas or SiH4 gas.

[0012] In one embodiment, preferably, in the pretreatment method for the AlN bonding interface provided by the present invention, continuously introducing a Si source gas to the surface of the substrate and the metal material within the preset duration to pretreat the bonding interface includes: controlling the flow rate range of the introduced Si source gas to be between 150 sccm and 300 sccm.

[0013] In one embodiment, preferably, in the pretreatment method for the AlN bonding interface provided by the present invention, continuously introducing a Si source gas to the surface of the substrate and the metal material within the preset duration to pretreat the bonding interface further includes: controlling the pressure range of the introduced Si source gas to be between 3 torr and 10 torr.

[0014] In one embodiment, preferably, in the pretreatment method for the AlN bonding interface provided by the present invention, the dielectric constant of the substrate is less than 3.9, and the metal material includes copper or cobalt.

[0015] In one embodiment, optionally, in the pretreatment method for the AlN bonding interface provided by the present invention, the other preset material includes ODC material and / or NDC material. Description of the Drawings

[0016] After reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings, the above features and advantages of the present invention can be better understood. In the drawings, the components are not necessarily drawn to scale, and components having similar relevant characteristics or features may have the same or similar reference numerals.

[0017] Figure 1 is a schematic flowchart of a method for preprocessing an AlN bonding interface according to one aspect of the present invention;

[0018] Figure 2 is a schematic diagram of a semiconductor multi-layer structure processed by the AlN bonding interface preprocessing method according to an embodiment of the present invention; and

[0019] Figure 3 is a flowchart of a semiconductor process method with an AlN bonding interface preprocessing step added according to an embodiment of the present invention.

[0020] For clarity, the following gives a brief description of the reference numerals:

[0021] 201 substrate

[0022] 202 copper

[0023] 203 cobalt

[0024] 204 preprocessing interface

[0025] 205 AlN

[0026] 206 other preset materials. Detailed Description of the Embodiments

[0027] The following describes the embodiments of the present invention by specific specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiments, this does not mean that the features of this invention are limited to this embodiment. On the contrary, the purpose of introducing the invention in conjunction with the embodiment is to cover other alternatives or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, many specific details will be included in the following description. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or obscuring the key points of the present invention, some specific details will be omitted in the description.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0029] In addition, the "upper", "lower", "left", "right", "top", "bottom", "horizontal", and "vertical" used in the following description should be understood as the orientations shown in this section and the relevant drawings. This relative term is only for convenience of description and does not represent that the device described needs to be manufactured or operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0030] It can be understood that although terms such as "first", "second", and "third" can be used herein to describe various components, regions, layers, and / or parts, these components, regions, layers, and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers, and / or parts. Therefore, the first component, region, layer, and / or part discussed below can be referred to as the second component, region, layer, and / or part without departing from some embodiments of the present invention.

[0031] To overcome the above-mentioned defects existing in the prior art, the present invention provides a pretreatment method for an AlN bonding interface, which is used to pretreat the bonding interface of an AlN material during semiconductor manufacturing by introducing a silicon source gas into the bonding interface of the AlN material, so as to improve the pore problem in the dielectric layer, improve the electrical isolation performance of the dielectric layer, and at the same time can also optimize the bonding strength between the metal material and the AlN material, and enhance the reliable performance of the semiconductor device structure.

[0032] Figure 1 It is a schematic flowchart of a method for a pretreatment method of an AlN bonding interface according to an aspect of the present invention.

[0033] Please refer to Figure 1 , the pretreatment method for the AlN bonding interface provided by the present invention is used to pretreat the bonding interface between the AlN material layer and the substrate and the metal material in a semiconductor device. The metal material is embedded in the substrate and the surface is flush. The pretreatment method 100 may include:

[0034] Step 101: At a preset temperature, introduce NH3 onto the surfaces of the substrate and the metal material placed in the deposition chamber to remove the metal oxide on the surface of the metal material;

[0035] Step 102: Continuously introduce Si source gas to the surface of the substrate and the metal material within a preset time duration to pre-treat the bonding interface; and

[0036] Step 103: Deposit AlN material on the bonding interface to form an AlN layer, and layer by layer deposit other preset materials on the AlN layer to form a multi-layer semiconductor structure.

[0037] Further, in a preferred embodiment, the pre-treatment method for the AlN bonding interface provided by the present invention may further include: introducing oxygen and helium into the deposition chamber before the reaction starts, and then applying a radio frequency power supply to make all the gases react in the form of plasma, and the power range of the radio frequency power supply is 250W - 750W.

[0038] It is easily understood by those skilled in the art that after the radio frequency power supply is turned on during the process, the radio frequency electricity will ionize the gas to form plasma, so that the reaction of the substances between layers can be more sufficient. If plasma is not formed, introducing gas into the reaction chamber generally only serves as a purging function. However, due to the heating at a preset temperature, some reactions may also occur, but the reaction effect is weak.

[0039] In a preferred embodiment, the preset temperature in Step 101 may be 250°C - 350°C. It is easily understood that performing the process reaction under heating conditions can make the reaction more sufficient, thereby improving the reaction effect.

[0040] The substrate in the present invention may be a low-k substrate or an ultra-low k substrate with a dielectric constant less than 3.9, and the metal material may include stacked copper or cobalt to form an electrode conductive structure. It is easily understood by those skilled in the art that the metal is embedded in the substrate structure, and their surfaces are flush. Then, a dielectric layer is deposited thereon, and the pre-treatment method provided by the present invention is exactly to pre-treat the contact surface between this surface and the dielectric layer, so as to improve the isolation effect of the dielectric layer and enhance the bonding between the metal and the substances at the interface.

[0041] Step 102 is a key step in the pre-treatment method for the AlN bonding interface provided by the present invention. The Si source gas introduced in Step 102 may include TSA gas or SiH4 gas.

[0042] It should be noted that the silicon source gas here is only an exemplary example and is not used to limit the protection scope of the present invention. The purpose of introducing the silicon source gas in this step is that the plasma of the silicon source gas can form an interfacial substance such as CuSiN with the metal surface, which can effectively improve the interfacial bonding between the metal material and AlN. At the same time, the Si-containing plasma can form a bond such as Si-O-SiN with the surface of the dielectric material, which can improve the interfacial defects of the dielectric material and prevent the penetration of the AlN dielectric layer during the subsequent deposition process, thereby affecting its electrical isolation performance. Finally, through the optimization of the AlN bonding interface by the silicon source gas, the occurrence probability of electromigration at the bonding interface is reduced, and the reliability of the semiconductor device is improved.

[0043] In a preferred embodiment, the silicon source gas is continuously introduced onto the surfaces of the substrate and the metal material for a preset duration to pre-treat the bonding interface. The range of the preset duration can be 15 s to 45 s, the flow rate range of the introduced silicon source gas is controlled between 150 sccm and 300 sccm, and the pressure range of the introduced silicon source gas is controlled between 3 torr and 10 torr.

[0044] Those skilled in the art can easily understand that these preferred process parameters, including the flow rate, pressure, and process duration of the silicon source gas, as well as the temperature and radio frequency power mentioned above, are all for improving the process effect and performance of the AlN bonding interface pre-treatment provided by the present invention, and are not used to limit the protection scope of the present invention. Under these preferred process parameters, the pre-treatment method of the AlN bonding interface provided by the present invention can effectively optimize and improve the bonding interface of the AlN material, enhance the electrical isolation performance of the dielectric layer, and at the same time enhance the bonding reliability between the metal material and the interface.

[0045] It should be noted that in the pre-treatment method of the AlN bonding interface provided by the present invention, the introduction of the silicon source gas is only for optimizing and improving the bonding interface, rather than for continuous film growth of silicon or silicide. Therefore, the reaction conditions of this pre-treatment step can also be simplified, without being as complicated as depositing a complete film layer, which also controls the process cost to a certain extent.

[0046] For example, in a preferred embodiment, continuously introducing the silicon source gas onto the surfaces of the substrate and the metal material for a preset duration to pre-treat the bonding interface may include: performing the step of introducing the silicon source gas to pre-treat the bonding interface by using the PECVD process, without using a dedicated deposition device such as ALD for pre-treatment work.

[0047] Figure 2 It is a schematic diagram of a semiconductor multi-layer structure after being treated by the AlN bonding interface pre-treatment method according to an embodiment of the present invention.

[0048] As Figure 2 shown, in the semiconductor structure targeted by the AlN bonding interface pretreatment method provided by the present invention, cobalt metal 203 and copper 202 are laminated and embedded in the substrate 201, and the surface of cobalt 203 is flush with the surfaces of other parts of the substrate 201. The substrate 201 can be made of one or more of SiOx, SiNx, SiON, low-k dielectric materials (i.e., materials with a dielectric constant greater than or equal to 2.5 but less than 3.9), or ultra-low-k dielectric materials, such as Figure 2 the SiOC material shown in

[0049] The AlN bonding interface pretreatment method provided by the present invention pre-treats the common interface between the above-mentioned metal and the substrate. As Figure 2 shown, subsequent layer-by-layer deposition of materials such as AlN 205 will be carried out on this interface. On the bonding interface between AlN 205 and the substrate and the metal, the pretreatment method for the AlN bonding interface provided by the present invention optimizes and improves this interface, that is, as described above, during the preparation process of this semiconductor structure, a silicon source gas is introduced into this bonding interface to pre-treat this bonding interface, thereby forming Figure 2 the pre-treated interface 204 shown in

[0050] Those skilled in the art can understand that the pre-treated interface 204 may not be a complete film layer, but only a pre-treatment product that pre-treats this bonding interface and reacts with the interface substances, which can enable the pre-treated interface 204 to form interface substances such as CuSiN with the metal surface, and can effectively improve the interface bonding between the metal material and AlN 205. At the same time, the pre-treated interface 204 and the surface of the substrate 201 can form bonds such as Si-O-SiN, which can improve the interface defects of the dielectric material and prevent the AlN dielectric layer from permeating during the subsequent deposition process, thereby affecting its electrical isolation performance. Finally, through the optimization of the AlN bonding interface by the silicon source gas, the occurrence probability of electromigration at this bonding interface is reduced, and the reliable performance of the semiconductor device is improved.

[0051] After the pretreatment of this bonding interface is completed, AlN material can be continuously deposited on this bonding interface to form an AlN layer, and other preset materials 206 can be layer-by-layer deposited on this AlN layer to form a multi-layer semiconductor structure.

[0052] In one embodiment, the other preset material 206 may include ODC material and / or NDC material. The ODC material is oxygen-doped silicon carbide (SiC:O), and the NDC material is nitrogen-doped silicon carbide (SiC:N). The upper layer material here may be a stack of a multi-layer material containing both, or a combination of the two. There is no specific limitation on the other preset material of the upper layer here.

[0053] Figure 3 It is a flowchart of a semiconductor process method after adding an AlN bonding interface pretreatment step according to an embodiment of the present invention.

[0054] Please refer to Figure 3 , in this embodiment, first perform step 301: Prepare a substrate, where the substrate includes the above-mentioned substrate material embedded with metal. Then perform step 302: Introduce NH3 into the reaction chamber and ionize NH3 to form a plasma for the first-step pretreatment work. This step can remove metal oxides on the surface of the substrate and the metal, such as CuO or CoO, etc., thereby enhancing the bonding ability between the metal and the dielectric layer.

[0055] After proper purging with NH3, the wafer remains in the reaction chamber. At this time, perform step 303: Introduce a silicon source gas into the reaction chamber and form a plasma through a radio frequency system to treat the surfaces of metals such as Cu / Co and substrate dielectric materials such as low-k / ULK.

[0056] After the pretreatment is completed, perform step 304: Remove the wafer from the chamber and move it to the next chamber for AlN deposition; and step 305: After the AlN deposition is completed, the wafer enters the next PECVD chamber to complete the post-treatment of AlN and the deposition of SiOC, and finally form a multi-layer structure.

[0057] In the above steps, steps 301 to 303, especially step 303, can be carried out in a PECVD device without using an ALD deposition device, which simplifies the process flow to a certain extent and reduces the process cost.

[0058] Although the above methods are illustrated and described as a series of actions for simplicity of explanation, it should be understood and appreciated that these methods are not limited by the order of the actions, because according to one or more embodiments, some actions may occur in a different order and / or occur concurrently with other actions not illustrated and described herein but understood by those skilled in the art.

[0059] The foregoing description of the disclosure has been provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and 229955 1CNCN

[0060] The general principles defined herein can be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A pretreatment method for an AlN bonding interface, which is used to pretreat the bonding interface between an AlN material layer and a substrate and a metal material in a semiconductor device. The metal material is embedded in the substrate and has a flush surface. The pretreatment method includes: At a preset temperature, introducing NH3 onto the surfaces of the substrate and the metal material placed in a deposition chamber to remove metal oxides on the surface of the metal material; Continuously introducing a Si source gas onto the surfaces of the substrate and the metal material for a preset duration, and applying a radio frequency power supply in the deposition chamber before the reaction starts, so that the plasma of the Si source gas reacts with the surface of the metal material to form an interfacial substance on the surface of the metal material that improves the bonding property between the metal material and AlN; And Depositing an AlN material on the interfacial substance to form an AlN layer, and successively depositing other preset materials on the AlN layer to form a multi-layer semiconductor structure.

2. The pretreatment method according to claim 1, characterized in that The power range of the radio frequency power supply is 250W - 750W.

3. The pretreatment method according to claim 1, characterized in that The range of the preset duration is 15s - 45s.

4. The pretreatment method according to claim 1, wherein The preset temperature is 250°C - 350°C.

5. The pretreatment method according to claim 1, characterized in that, The step of continuously introducing a Si source gas onto the surfaces of the substrate and the metal material for a preset duration includes: Performing the introduction of the Si source gas using a PECVD process.

6. The pretreatment method according to claim 1, wherein The Si source gas includes TSA gas or SiH4 gas.

7. The pretreatment method according to claim 6, wherein The step of continuously introducing a Si source gas onto the surfaces of the substrate and the metal material for a preset duration further includes: Controlling the flow rate range of the introduced Si source gas to be between 150 sccm and 300 sccm.

8. The pretreatment method according to claim 6, wherein The step of continuously introducing a Si source gas onto the surfaces of the substrate and the metal material for a preset duration further includes: Controlling the pressure range of the introduced Si source gas to be between 3 torr and 10 torr.

9. The preprocessing method according to claim 1, wherein The dielectric constant of the substrate is less than 3.9, and the metal material includes copper or cobalt.

10. The pretreatment method according to claim 1, wherein The other preset materials include ODC materials and / or NDC materials.

Images