Cobalt-based magnetic film inductor and manufacturing method thereof

Abstract

The invention provides a cobalt-based magnetic film inductor and a manufacturing method thereof, and belongs to the technical field of semiconductor devices. The cobalt-based magnetic film inductor comprises a substrate layer, a magnetic layer, an insulating layer and a metal coil layer. The substrate layer is made of glass; the magnetic layer is arranged on the upper surface of the substrate layer, and the magnetic layer is made of a cobalt-based amorphous soft magnetic material; the insulating layer is arranged on the surface, away from the substrate layer, of the magnetic layer and uniformly covers the upper surface of the magnetic layer; the metal coil layer is arranged on the surface, away from the substrate layer, of the insulating layer. The cobalt-based magnetic thin film inductor is prepared through the MEMS technology, the miniaturization of the size of the inductor is ensured, meanwhile, glass is used as the substrate, the cobalt-based amorphous soft magnetic material is used as the magnetic layer, and the high inductance value and quality factor of the thin film inductor are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a cobalt-based magnetic thin film inductor and a manufacturing method thereof. Background Art

[0002] Inductors are one of the three core components in electronic circuits, playing key roles such as filtering noise, screening signals, maintaining current stability, and suppressing electromagnetic interference. Inductors are widely used in a variety of electronic products such as communications, computers, audio and video equipment, household appliances, automated electronic equipment, and telecommunications and broadcasting equipment. With the continuous advancement of micro-electromechanical system (MEMS) technology and semiconductor integrated circuit technology, electronic circuits are becoming more miniaturized, lightweight, and integrated, which puts higher requirements on the performance of inductors. In the early days, planar inductors were mainly hollow inductors without magnetic cores. Since there was no magnetic loss caused by the magnetic core material, planar inductors were able to achieve higher quality factors Q and self-resonant frequencies. However, the inductance density of hollow inductors is low. In order to achieve sufficient inductance and quality factors in integrated circuits, a large number of coils are inevitably required, resulting in a larger volume, which conflicts with the miniaturization trend of integrated circuits. In order to significantly reduce the number of coil turns and reduce the size of the inductor, the use of magnetic thin film technology to manufacture thin film inductors has become an innovative solution. Although planar inductors combined with magnetic films can significantly improve inductance performance, their operating frequency is relatively low, and it is difficult to achieve high inductance value and high quality factor at high frequencies. Summary of the invention

[0003] The present invention provides a cobalt-based magnetic thin film inductor and a manufacturing method thereof, which are used to solve the problem in the prior art that it is difficult for the inductor to achieve a high inductance value and a high quality factor at high frequencies.

[0004] The present invention provides a cobalt-based magnetic thin film inductor, comprising: a substrate layer, a magnetic layer, an insulating layer and a metal coil layer; wherein: The magnetic layer is arranged on the surface of the substrate layer; The insulating layer is disposed on a surface of the magnetic layer away from the substrate layer and uniformly covers the surface of the magnetic layer away from the substrate layer; and The metal coil layer is arranged on a surface of the insulating layer away from the substrate layer; Wherein, the substrate layer is a glass substrate, and the material of the magnetic layer is a cobalt-based amorphous soft magnetic material.

[0005] In one embodiment, the magnetic layer is obtained by depositing the cobalt-based amorphous soft magnetic material on the substrate layer through a deposition process; and the insulating layer is obtained by depositing silicon dioxide or silicon nitride on the surface of the magnetic layer away from the substrate layer through a deposition process.

[0006] In one embodiment, the metal coil layer is obtained by the following steps: Depositing a metal film layer on a surface of the insulating layer away from the substrate layer through a deposition process; Using photoresist and performing photolithography, a coil mask pattern is formed on a surface of the metal film layer away from the substrate layer; The metal film layer is etched by an etching process to obtain a metal coil; and The photoresist is removed to expose the metal coil, thereby obtaining the metal coil layer.

[0007] In one embodiment, the deposition process is any one of physical vapor deposition, chemical vapor deposition and atomic layer deposition.

[0008] In one embodiment, the metal coil layer is obtained by the following steps: A metal sheet having a pattern of the metal coil layer is customized as a mask, wherein the size of the metal sheet is larger than the size of the glass substrate, and the thickness of the metal sheet is larger than the thickness of the metal coil layer, wherein the coil area of ​​the pattern on the metal sheet is a through hole, and the remaining area is solid metal; Covering the metal sheet on the surface of the insulating layer away from the substrate layer and aligning the surface, and clamping and fixing the metal sheet and the glass substrate by a clamp; Preparing a metal layer on the surface of the insulating layer covered by the metal sheet and away from the substrate layer by a sputtering process or an evaporation process; and After the metal layer is prepared, the metal sheet is removed and cleaned.

[0009] The present invention also provides a method for manufacturing a cobalt-based magnetic thin film inductor, comprising: providing a glass substrate as a backing layer; Making a magnetic layer on the upper surface of the substrate layer; An insulating layer is formed on the surface of the magnetic layer away from the substrate layer, so that the insulating layer uniformly covers the surface of the magnetic layer away from the substrate layer; and Making a metal coil layer on a surface of the insulating layer away from the substrate layer; Wherein, the material of the magnetic layer is cobalt-based amorphous soft magnetic material.

[0010] In one embodiment, forming a magnetic layer on the upper surface of the substrate layer includes: depositing the cobalt-based amorphous soft magnetic material on the substrate layer through a deposition process to obtain the magnetic layer; and forming an insulating layer on the surface of the magnetic layer away from the substrate layer includes: depositing a silicon dioxide or silicon nitride insulating layer on the surface of the magnetic layer away from the substrate layer through a deposition process to obtain the insulating layer.

[0011] In one embodiment, a metal coil layer is formed on a surface of the insulating layer away from the substrate layer, comprising: Depositing a metal film layer on a surface of the insulating layer away from the substrate layer through a deposition process; Using photoresist and performing photolithography, a coil mask pattern is formed on a surface of the metal film layer away from the substrate layer; The metal film layer is etched by an etching process to obtain a metal coil; and The photoresist is removed to expose the metal coil.

[0012] In one embodiment, the deposition process is any one of physical vapor deposition, chemical vapor deposition and atomic layer deposition.

[0013] In one embodiment, a metal coil layer is formed on a surface of the insulating layer away from the substrate layer, comprising: A metal sheet having a pattern of the metal coil layer is customized as a mask, wherein the size of the metal sheet is larger than the size of the glass substrate, and the thickness of the metal sheet is larger than the thickness of the metal coil layer, wherein the coil area of ​​the pattern on the metal sheet is a through hole, and the remaining area is solid metal; Covering the metal sheet on the surface of the insulating layer away from the substrate layer and aligning the surface, and clamping and fixing the metal sheet and the glass substrate by a clamp; Preparing a metal layer on the surface of the insulating layer covered by the metal sheet and away from the substrate layer by a sputtering process or an evaporation process; and After the metal layer is prepared, the metal sheet is removed and cleaned.

[0014] The present invention uses a glass substrate as a substrate layer, adopts a cobalt-based amorphous soft magnetic material to make a magnetic layer on the surface of the substrate layer, makes an insulating layer on the surface of the magnetic layer, and makes the insulating layer evenly cover the magnetic layer, and then makes a metal coil layer on the surface of the insulating layer, and completes the preparation of the thin film inductor through the MEMS process, thereby ensuring the miniaturization of the inductor volume. At the same time, by using the cobalt-based amorphous soft magnetic material as the magnetic layer, a higher inductance and quality factor of the thin film inductor are achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. 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 cross-sectional structure diagram of a cobalt-based magnetic thin film inductor according to an embodiment of the present invention; Figure 2 is a schematic flow chart of a method for preparing a cobalt-based magnetic thin film inductor according to an embodiment of the present invention; Figure 3 1 is a schematic diagram of phase results of a method for preparing a cobalt-based magnetic thin film inductor according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other in the absence of conflict. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0019] It should be further noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0020] In the present invention, "at least one" means one or more, and "more" means two or more than two. The terms "first", "second", "third", "fourth", etc. (if any) in the present invention are used to distinguish similar objects, rather than to describe a specific order or sequence.

[0021] In the embodiments of the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0022] The following will refer to Figures 1 to 3 Embodiments of the present invention are described.

[0023] The present invention provides a cobalt-based magnetic thin film inductor, such as Figure 1 As shown, it includes: a substrate layer 101 , a magnetic layer 102 , an insulating layer 103 and a metal coil layer 104 .

[0024] Specifically, the material of the substrate layer 101 is glass; the magnetic layer 102 is arranged on the upper surface of the substrate layer 101, and the material of the magnetic layer 102 is cobalt-based amorphous soft magnetic material; the insulating layer 103 is arranged on the surface of the magnetic layer 102 away from the substrate layer 101 (i.e., the upper surface), and uniformly covers the upper surface of the magnetic layer 102, and the material of the insulating layer can be silicon dioxide or silicon nitride; the metal coil layer 104 is arranged on the surface of the insulating layer 103 away from the substrate layer 101.

[0025] In the above-mentioned embodiment, the thin film inductor is prepared by MEMS process, which ensures the miniaturization of the inductor volume. Cobalt-based amorphous soft magnetic material is used as the magnetic layer. The high saturation magnetization intensity of the cobalt-based amorphous soft magnetic material can achieve a higher inductance. Its high resistivity can effectively reduce the eddy current loss generated under high frequency and achieve a higher quality factor. The glass substrate is used as the substrate, which can reduce the substrate loss and further improve the quality factor, thereby achieving a higher inductance and quality factor of the thin film inductor.

[0026] In one embodiment, the magnetic layer 102 is obtained by physical vapor deposition, by depositing a cobalt-based amorphous soft magnetic material on the upper surface of the substrate layer 101. The insulating layer 103 is obtained by chemical vapor deposition, by depositing, for example, silicon dioxide or silicon nitride on the surface of the magnetic layer 102 away from the substrate layer 101. Although the embodiment describes that a specific deposition process is used to form the magnetic layer 102 and the insulating layer 103, this is exemplary, and the deposition process used can be any one of physical vapor deposition, chemical vapor deposition, and atomic layer deposition.

[0027] In one embodiment, the metal coil layer 104 is obtained by the following steps: depositing a metal film layer on the surface of the insulating layer 103 away from the substrate layer 101 by physical vapor deposition; using photoresist, making a coil mask pattern on the surface of the metal film layer away from the substrate layer 101 by photolithography; etching the metal film layer by wet etching to obtain a metal coil; and removing the photoresist to expose the metal coil to obtain the metal coil layer 104. Although the embodiment describes that a specific deposition process is used to form the metal film layer, this is exemplary, and the deposition process used can be any one of physical vapor deposition, chemical vapor deposition and atomic layer deposition. As an example, dry etching can also be used to etch the metal film layer.

[0028] In another embodiment, the metal coil layer 104 is obtained by the following steps: a metal sheet containing the desired pattern of the metal coil layer 104 is customized as a mask, the size of the metal sheet is slightly larger than the size of the glass substrate forming the substrate layer, and the thickness of the metal sheet is slightly larger than the desired thickness of the metal coil layer 104, wherein on the metal sheet, the coil area of ​​the pattern is a through hole, and the remaining area is solid metal; the metal sheet is covered on the surface of the insulating layer 103 away from the substrate layer 101 (i.e., the upper surface of the insulating layer) and aligned, and the metal sheet and the glass substrate are clamped and fixed by a specific fixture; a metal layer is prepared on the upper surface of the insulating layer 103 covered by the metal sheet by sputtering or evaporation; and after the metal layer is prepared, the metal sheet is removed and cleaned. Since the metal sheet covers the area other than the coil on the insulating layer when the sputtering or evaporation process is implemented, only the metal coil pattern is left on the insulating layer 103 after the metal sheet is removed, thereby obtaining the metal coil layer.

[0029] The following is a description of a method for manufacturing a cobalt-based magnetic thin film inductor provided by the present invention. The method for manufacturing the cobalt-based magnetic thin film inductor described below and the cobalt-based magnetic thin film inductor described above can be referred to each other.

[0030] The present invention also provides a method for manufacturing a cobalt-based magnetic thin film inductor, which is used to manufacture the cobalt-based magnetic thin film inductor. Figure 2 As shown, including: Step S101, providing a glass substrate as a backing layer.

[0031] Specifically, a glass substrate is provided, and the glass substrate is cleaned and rinsed to serve as a substrate layer.

[0032] Step S102: using a cobalt-based magnetic thin film material to form a magnetic layer on the upper surface of the substrate layer.

[0033] Specifically, a cobalt-based magnetic thin film material is deposited on the upper surface of the substrate layer through a deposition process to obtain a magnetic layer. As an example, a physical vapor deposition method can be used to deposit a magnetic layer on the upper surface of the substrate layer to form a magnetic layer. Figure 3 The wafer shown in step one.

[0034] Step S103 , forming an insulating layer on the surface of the magnetic layer away from the substrate layer, and making the insulating layer uniformly cover the surface of the magnetic layer away from the substrate layer.

[0035] Specifically, based on the wafer with the magnetic layer obtained in step S102, a deposition process is used to deposit, for example, silicon dioxide or silicon nitride as an insulating layer on the surface of the magnetic layer away from the substrate layer (i.e., the upper surface). As an example, the insulating layer can be deposited by chemical vapor deposition, and the insulating layer is uniformly covered on the upper surface of the magnetic layer to form a Figure 3 The wafer shown in step 2.

[0036] Step S104 , forming a metal coil layer on a surface of the insulating layer away from the substrate layer.

[0037] Specifically, based on the wafer with the magnetic layer and the insulating layer obtained in the above step S103, a metal film layer is deposited on the surface of the insulating layer away from the substrate layer (ie, the upper surface) by a physical vapor deposition process to form a Figure 3 The wafer shown in the third step. Then use photoresist to make a coil mask pattern on the surface of the metal film layer through a photolithography process to form a photoresist mask, and obtain Figure 3 The wafer shown in the fourth step. Then, the metal film layer with the photoresist mask is etched by an etching process to obtain a metal coil, forming a Figure 3 The wafer shown in step 5. Finally, the metal coil layer is obtained by removing the photoresist to expose the metal, forming a Figure 3 The wafer shown in step 6. The etching process used can be dry etching or wet etching.

[0038] In the above-mentioned embodiment, the thin film inductor is prepared by MEMS process, which ensures the miniaturization of the inductor volume. Cobalt-based amorphous soft magnetic material is used as the magnetic layer. The high saturation magnetization intensity of the cobalt-based amorphous soft magnetic material can achieve a higher inductance. Its high resistivity can effectively reduce the eddy current loss generated under high frequency and achieve a higher quality factor. The glass substrate is used as the substrate, which can reduce the substrate loss and further improve the quality factor, thereby achieving a higher inductance and quality factor of the thin film inductor.

[0039] It is noted that the deposition process used in step S102, step S103 and step S104 of the above embodiment is not limited to the specific deposition process given in the embodiment, but can be any one of physical vapor deposition, chemical vapor deposition and atomic layer deposition.

[0040] In another embodiment, the step of making a metal coil layer on the surface of the insulating layer away from the substrate layer in step S104 is as follows: a metal sheet containing the pattern of the desired metal coil layer is customized as a mask, the size of the metal sheet is slightly larger than the size of the glass substrate, and the thickness of the metal sheet is slightly larger than the thickness of the desired metal coil layer, wherein on the metal sheet, the coil area of ​​the pattern of the metal coil layer is a through hole, and the remaining area is solid metal; the metal sheet is covered on the surface of the insulating layer away from the substrate layer (i.e., the upper surface of the insulating layer) and aligned, and the metal sheet and the glass substrate are clamped and fixed by a specific clamp; a metal layer is prepared on the upper surface of the insulating layer covered by the metal sheet by sputtering or evaporation; after the metal layer is prepared, the metal sheet is removed and cleaned. Since the metal sheet covers the area other than the coil on the insulating layer when the sputtering or evaporation process is implemented, only the metal coil pattern is left on the insulating layer after the metal sheet is removed, thereby obtaining a metal coil layer.

[0041] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cobalt-based magnetic thin film inductor, characterized in that: include: substrate layer, magnetic layer, insulating layer and metal coil layer; wherein, The magnetic layer is arranged on the surface of the substrate layer; The insulating layer is disposed on a surface of the magnetic layer away from the substrate layer and uniformly covers the surface of the magnetic layer away from the substrate layer; and The metal coil layer is arranged on a surface of the insulating layer away from the substrate layer; Wherein, the substrate layer is a glass substrate, and the material of the magnetic layer is a cobalt-based amorphous soft magnetic material.

2. The cobalt-based magnetic thin film inductor according to claim 1, characterized in that: The magnetic layer is obtained by depositing the cobalt-based amorphous soft magnetic material on the substrate layer through a deposition process; and The insulating layer is obtained by depositing silicon dioxide or silicon nitride on the surface of the magnetic layer away from the substrate layer through a deposition process.

3. The cobalt-based magnetic thin film inductor according to claim 1, characterized in that: The metal coil layer is obtained by the following steps: Depositing a metal film layer on a surface of the insulating layer away from the substrate layer through a deposition process; Using photoresist and performing photolithography, a coil mask pattern is formed on a surface of the metal film layer away from the substrate layer; The metal film layer is etched by an etching process to obtain a metal coil; and The photoresist is removed to expose the metal coil, thereby obtaining the metal coil layer.

4. The cobalt-based magnetic thin film inductor according to claim 2 or 3, characterized in that: The deposition process is any one of physical vapor deposition, chemical vapor deposition and atomic layer deposition.

5. The cobalt-based magnetic thin film inductor according to claim 1, characterized in that: The metal coil layer is obtained by the following steps: A metal sheet having a pattern of the metal coil layer is customized as a mask, wherein the size of the metal sheet is larger than the size of the glass substrate, and the thickness of the metal sheet is larger than the thickness of the metal coil layer, wherein the coil area of ​​the pattern on the metal sheet is a through hole, and the remaining area is solid metal; Covering the metal sheet on the surface of the insulating layer away from the substrate layer and aligning the surface, and clamping and fixing the metal sheet and the glass substrate by a clamp; Preparing a metal layer on the surface of the insulating layer covered by the metal sheet and away from the substrate layer by a sputtering process or an evaporation process; and After the metal layer is prepared, the metal sheet is removed and cleaned.

6. A method for manufacturing a cobalt-based magnetic thin film inductor, characterized in that: include: providing a glass substrate as a backing layer; Making a magnetic layer on the upper surface of the substrate layer; An insulating layer is formed on the surface of the magnetic layer away from the substrate layer, so that the insulating layer uniformly covers the surface of the magnetic layer away from the substrate layer; and Making a metal coil layer on a surface of the insulating layer away from the substrate layer; Wherein, the material of the magnetic layer is cobalt-based amorphous soft magnetic material.

7. The manufacturing method according to claim 6, characterized in that: The manufacturing of the magnetic layer on the upper surface of the substrate layer comprises: depositing the cobalt-based amorphous soft magnetic material on the substrate layer through a deposition process to obtain the magnetic layer; and The step of manufacturing the insulating layer on the surface of the magnetic layer away from the substrate layer comprises: depositing a silicon dioxide or silicon nitride insulating layer on the surface of the magnetic layer away from the substrate layer through a deposition process to obtain the insulating layer.

8. The manufacturing method according to claim 6, characterized in that: Producing a metal coil layer on a surface of the insulating layer away from the substrate layer comprises: Depositing a metal film layer on a surface of the insulating layer away from the substrate layer through a deposition process; Using photoresist and performing photolithography, a coil mask pattern is formed on a surface of the metal film layer away from the substrate layer; The metal film layer is etched by an etching process to obtain a metal coil; and The photoresist is removed to expose the metal coil.

9. The production method according to claim 7 or 8, characterized in that: The deposition process is any one of physical vapor deposition, chemical vapor deposition and atomic layer deposition.

10. The manufacturing method according to claim 6, characterized in that: Producing a metal coil layer on a surface of the insulating layer away from the substrate layer comprises: A metal sheet having a pattern of the metal coil layer is customized as a mask, wherein the size of the metal sheet is larger than the size of the glass substrate, and the thickness of the metal sheet is larger than the thickness of the metal coil layer, wherein the coil area of ​​the pattern on the metal sheet is a through hole, and the remaining area is solid metal; Covering the metal sheet on the surface of the insulating layer away from the substrate layer and aligning the surface, and clamping and fixing the metal sheet and the glass substrate by a clamp; Preparing a metal layer on the surface of the insulating layer covered by the metal sheet and away from the substrate layer by a sputtering process or an evaporation process; and After the metal layer is prepared, the metal sheet is removed and cleaned.

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