Method for preparing dielectric film layer and semiconductor device

Abstract

The present invention provides a method for preparing a dielectric film layer and a semiconductor device, which belongs to the field of semiconductor manufacturing. The method includes arranging a metal electrode on a substrate; forming a first silicon oxide layer on the substrate and the metal electrode using a high-pressure stress material, wherein the thickness of the first silicon oxide layer is greater than the thickness of the metal electrode; grinding the first silicon oxide layer until the metal electrode is exposed on the surface of the first silicon oxide layer; depositing a second silicon oxide layer on the surface of the first silicon oxide layer and the metal electrode using a low-pressure stress material, wherein the first silicon oxide layer and the second silicon oxide layer constitute a dielectric film layer, wherein the compressive stress of the low-pressure stress material is lower than the compressive stress of the high-pressure stress material, and the compressive stress value range of the high-pressure stress material is not less than 150MPa. Through the processing scheme of the present application, leakage between metal electrodes is avoided, and the reliability of the process is improved.

Description

Technical Field

[0001] The invention relates to the field of semiconductor manufacturing, and in particular to a method for preparing a dielectric film layer and a semiconductor device. Background Art

[0002] SiO2 has extremely stable chemical properties and a certain masking effect on the diffusion of impurities. It is an excellent insulating material. Therefore, SiO2 is widely used in the manufacturing process of integrated circuits and semiconductors, and SiO2 is also often selected in the selection of dielectric layers.

[0003] Generally, HDPCVD (high-density plasma chemical vapor deposition) is used to form SiO2 on the substrate. When there are metal electrodes in semiconductor devices, SiO2 will be affected by plasma and will show compressive stress characteristics. It will interact with the metal, especially the metal top corners will be affected by the lateral and longitudinal forces, which will easily cause cracks. The metal will diffuse into the cracked space, so the adjacent metal electrodes will easily cause leakage between the metals, which will lead to abnormal parameters and failure of integrated circuits or semiconductors. Summary of the invention

[0004] Therefore, in order to overcome the above-mentioned shortcomings of the prior art, the present invention provides a method for preparing a dielectric film layer and a semiconductor device for eliminating cracks.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a method for preparing a dielectric film layer, comprising: arranging a metal electrode on a substrate; forming a first silicon oxide layer on the substrate and the metal electrode using a high pressure stress material, wherein the thickness of the first silicon oxide layer is greater than the thickness of the metal electrode; grinding the first silicon oxide layer until the metal electrode is exposed on the surface of the first silicon oxide layer; depositing a second silicon oxide layer on the surface of the first silicon oxide layer and the metal electrode using a low pressure stress material, wherein the first silicon oxide layer and the second silicon oxide layer constitute a dielectric film layer, wherein the compressive stress of the low pressure stress material is lower than the compressive stress of the high pressure stress material, and the compressive stress value range of the high pressure stress material is not less than 150MPa.

[0006] In one of the embodiments, the method of forming a first silicon oxide layer on the substrate and the metal electrode using a high pressure stress material includes: setting the pressure in the processing chamber to a predetermined pressure range, and setting the temperature of the substrate to a predetermined temperature range; supplying a processing gas mixture to a gas distribution device, wherein the processing gas mixture includes a gas of the high pressure stress material, a gas containing an oxygen substance, and argon gas, wherein the argon gas accounts for more than 20% of the volume of the processing gas mixture; and using a high-density plasma chemical vapor deposition method to deposit silicon dioxide on the substrate and the metal electrode using the high pressure stress material to form a first silicon oxide layer.

[0007] In one embodiment, the predetermined temperature range is from 400° C. to 600° C., and the predetermined pressure range is from 300 Pa to 600 Pa.

[0008] In one embodiment, the first silicon oxide layer is polished by chemical mechanical polishing.

[0009] In one embodiment, the low compressive stress material is any one of tetraethyl silicate and spin-on glass raw material.

[0010] In one embodiment, the thickness of the second silicon oxide layer is 0.3 to 3 times the thickness of the metal electrode.

[0011] In one embodiment, the metal electrode is a copper-aluminum alloy.

[0012] In one embodiment, a first radius of curvature of the first silicon oxide layer and a second radius of curvature of the second silicon oxide layer are calculated respectively; and a stress between the silicon oxide layers is obtained according to a difference between the first radius of curvature and the second radius of curvature, and the stress is not less than 200 MPa.

[0013] A semiconductor device, characterized in that the dielectric film layer of the semiconductor device is prepared by adopting the above method.

[0014] Compared with the prior art, the advantages of the present invention are: the cracks that have occurred are removed by grinding the first silicon oxide layer to the top of the metal, and the second silicon oxide layer is deposited on the surface of the first silicon oxide layer and the metal electrode through a low-pressure stress material to avoid the recurrence of cracking problems, thereby avoiding leakage between metal electrodes, reducing problems such as abnormal parameters and failure of integrated circuits or semiconductors, and improving the reliability of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 is a schematic flow chart of a method for preparing a dielectric film layer in an embodiment of the present invention;

[0017] Figure 2 is a schematic diagram of deposition of a first silicon oxide layer in an embodiment of the present invention;

[0018] Figure 3 is a schematic diagram of polishing the first silicon oxide layer in an embodiment of the present invention;

[0019] Figure 4 Schematic diagram of deposition of the second silicon oxide layer in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0021] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0022] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0023] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0024] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0025] like Figure 1 As shown, the embodiment of the present application provides a method for preparing a dielectric film layer, comprising:

[0026] Step 101: Dispose a metal electrode on a substrate.

[0027] The substrate can be any suitable semiconductor substrate material, specifically but not limited to silicon, germanium, silicon germanium, SOI (silicon on insulator), silicon carbide, gallium arsenide or any III / V compound semiconductor, etc. The metal electrode can be selected according to the semiconductor requirements, and can be copper, aluminum, gold, silver, etc., or alloys.

[0028] Step 102: Form a first silicon oxide layer on the substrate and the metal electrode using a high pressure stress material. The thickness of the first silicon oxide layer is greater than the thickness of the metal electrode.

[0029] A first silicon oxide layer is formed on the substrate and the metal electrode using a high pressure stress material, and the thickness of the first silicon oxide layer is greater than the thickness of the metal electrode. Figure 2 As shown, the first silicon oxide layer needs to completely cover the metal electrode, and a gap is generated at the edge junction of the first silicon oxide layer and the metal electrode. In one embodiment, a high-pressure stress material is used to form a first silicon oxide layer on the substrate and the metal electrode. Specifically, high-density plasma chemical vapor deposition is performed on the metal electrode and the substrate; the deposition sputtering ratio D / S of the deposition process can be 2.1 to 3.5, the power is 2800 to 3200W, and the gas flow rate is 100 to 120sccm of argon, 80-100sccm of oxygen, and 40 to 50sccm of SiH4 and SiF4; plasma-enhanced chemical vapor deposition is performed on the substrate, the gap between the metal electrode, and the metal electrode to form a first silicon oxide layer composed of silicon dioxide.

[0030] Step 103: grinding the first silicon oxide layer until the metal electrode is exposed on the surface of the first silicon oxide layer.

[0031] like Figure 3 As shown, the first silicon oxide layer is ground until the metal electrode is exposed on the surface of the first silicon oxide layer. The grinding method can be chemical grinding, mechanical grinding or chemical mechanical grinding method. In one embodiment, the first silicon oxide layer is ground by chemical mechanical grinding. The specific implementation conditions of the chemical mechanical grinding method are to use a grinding liquid suitable for silicon oxide and use a fixed time method to keep the remaining silicon oxide thickness to the expected target value.

[0032] Step 104, depositing a second silicon oxide layer on the surface of the first silicon oxide layer and the metal electrode using a low compressive stress material, the first silicon oxide layer and the second silicon oxide layer constitute a dielectric film layer, the compressive stress of the low compressive stress material is lower than the compressive stress of the high compressive stress material, and the compressive stress value range of the high compressive stress material is not less than 150 MPa.

[0033] like Figure 4As shown, a second silicon oxide layer is deposited on the surface of the first silicon oxide layer and the metal electrode through a low compressive stress material, the first silicon oxide layer and the second silicon oxide layer constitute a dielectric film layer, the compressive stress of the low compressive stress material is lower than the compressive stress of the high pressure stress material, and the compressive stress value range of the high pressure stress material is not less than 150MPa. In one embodiment, the low compressive stress material is any one of tetraethyl silicate (TEOS) and spin-on glass (SOG) raw materials. In this step, the second silicon oxide layer can be deposited by the same deposition method as the first silicon oxide layer, or by other common deposition methods.

[0034] A semiconductor device, the dielectric film layer of the semiconductor device is prepared by adopting the above method.

[0035] The above method and semiconductor device remove the cracks that have occurred by grinding the first silicon oxide layer to the top of the metal, and deposit a second silicon oxide layer on the surface of the first silicon oxide layer and the metal electrode through a low-pressure stress material to avoid the recurrence of cracking problems, thereby avoiding leakage between metal electrodes, reducing problems such as abnormal integrated circuit or semiconductor parameters and failure, and improving process reliability.

[0036] In one embodiment, forming a first silicon oxide layer on a substrate and a metal electrode using a high pressure stress material comprises: setting the pressure in a processing chamber to a predetermined pressure range, setting the temperature of the substrate to a predetermined temperature range; supplying a processing gas mixture to a gas distribution device, wherein the processing gas mixture comprises a gas of the high pressure stress material, a gas containing an oxygen substance, and argon gas, wherein the argon gas accounts for more than 20% of the volume of the processing gas mixture; and depositing silicon dioxide on the substrate and the metal electrode using a high density plasma chemical vapor deposition method to form a first silicon oxide layer. The gas containing an oxygen substance may be oxygen or nitrous oxide (N2O). The gas of the high pressure stress material is a silicon-containing gas source such as SiH4. The gas containing an oxygen substance is supplied at a flow rate in a range of 15 slm to 30 slm. Preferably, the gas containing an oxygen substance is supplied at a flow rate in a range of 20 slm to 25 slm. The gas of the high pressure stress material is supplied at a flow rate in a range of 40 sccm to 70 sccm, preferably, at a flow rate in a range of 50 sccm to 60 sccm.

[0037] In one embodiment, the predetermined temperature range is from 400° C. to 600° C., and the predetermined pressure range is from 300 Pa to 600 Pa.

[0038] In one embodiment, the thickness of the second silicon oxide layer is 0.3 to 3 times the thickness of the metal electrode.

[0039] In one embodiment, the metal electrode is a copper-aluminum alloy.

[0040] In one embodiment, a first radius of curvature of the first silicon oxide layer and a second radius of curvature of the second silicon oxide layer are calculated respectively; and a stress between the silicon oxide layers is obtained according to a difference between the first radius of curvature and the second radius of curvature, and the stress is not less than 200 MPa.

[0041] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for preparing a dielectric film layer, characterized in that: include: Disposing a metal electrode on the substrate; Forming a first silicon oxide layer on the substrate and the metal electrode using a high pressure stress material, wherein the thickness of the first silicon oxide layer is greater than the thickness of the metal electrode; Grinding the first silicon oxide layer until the metal electrode is exposed on the surface of the first silicon oxide layer; A second silicon oxide layer is deposited on the surface of the first silicon oxide layer and the metal electrode through a low compressive stress material, the first silicon oxide layer and the second silicon oxide layer constitute a dielectric film layer, the compressive stress of the low compressive stress material is lower than the compressive stress of the high pressure stress material, and the compressive stress value range of the high pressure stress material is not less than 150Mpa, The method of forming a first silicon oxide layer on the substrate and the metal electrode using a high pressure stress material comprises: Setting the pressure in the processing chamber to a predetermined pressure range, and setting the temperature of the substrate to a predetermined temperature range; supplying a process gas mixture to a gas distribution device, wherein the process gas mixture includes a gas of a high compressive stress material, a gas containing an oxygen species, and argon gas, wherein the argon gas accounts for more than 20% by volume of the process gas mixture; The high-pressure stress material is deposited on the substrate and the metal electrode using a high-density plasma chemical vapor deposition method to form a first silicon oxide layer. The low compressive stress material is any one of tetraethyl silicate and spin-on glass raw material. The gas of the high pressure stress material is a silicon-containing gas source, The second silicon oxide layer is deposited by a low compressive stress material to avoid the cracking problem, thereby preventing leakage between metal electrodes.

2. The method according to claim 1, characterized in that The predetermined temperature range is from 400° C. to 600° C., and the predetermined pressure range is from 300 Pa to 600 Pa.

3. The method according to claim 1, characterized in that The first silicon oxide layer is polished by a chemical mechanical polishing method.

4. The method according to claim 1, characterized in that: The thickness of the second silicon oxide layer is 0.3 to 3 times the thickness of the metal electrode.

5. The method according to claim 1, characterized in that: The metal electrode is copper-aluminum alloy.

6. The method according to claim 1, characterized in that respectively calculating a first radius of curvature of the first silicon oxide layer and a second radius of curvature of the second silicon oxide layer; According to the difference between the first radius of curvature and the second radius of curvature, the stress between the silicon oxide layers is obtained, and the stress is not less than 200 MPa.

7. A semiconductor device, characterized in that: The dielectric film layer of the semiconductor device is prepared by the method according to any one of claims 1 to 6.

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