阅读说明：本技术 一种精确控制镀层厚度的电镀方法 (Electroplating method for accurately controlling thickness of coating ) 是由 王功 王旭阳 李雪征 李俊慧 冯亚丽 郭育梅 贾赫 于 2021-06-21 设计创作，主要内容包括：本发明公开一种精确控制镀层厚度的电镀方法,包括：在待镀基板上制作图形化种子层；根据无图形种子层上电镀得到的电极厚度分布梯度,将待镀基板上的图形化种子层划分为至少两个独立区域,每一个独立区域对应于一个厚度区间的分布区域；在待镀基板和图形化种子层上制作电镀掩膜图形；在带有电镀掩膜图形和图形化种子层的待镀基板上的针对不同独立区域按顺序依次电镀金属层,形成金属电极。上述方案,根据无图形种子层上电镀得到的电极厚度分布梯度,将待镀基板上的图形化种子层划分为至少两个独立区域,针对不同独立区域分别进行电镀控制,从而使不同独立区域电镀得到的金属层的厚度满足需要,使最终得到的金属电极的不同区域的厚度得到精确控制。(The invention discloses an electroplating method for accurately controlling the thickness of a coating, which comprises the following steps: manufacturing a graphical seed layer on a substrate to be plated; dividing a patterned seed layer on a substrate to be plated into at least two independent areas according to the electrode thickness distribution gradient obtained by electroplating on the non-patterned seed layer, wherein each independent area corresponds to a distribution area of a thickness interval; manufacturing an electroplating mask pattern on the substrate to be plated and the patterned seed layer; and sequentially electroplating metal layers aiming at different independent areas on the substrate to be plated with the electroplating mask pattern and the graphical seed layer to form metal electrodes. According to the scheme, the patterned seed layer on the substrate to be plated is divided into at least two independent areas according to the electrode thickness distribution gradient obtained by electroplating on the non-patterned seed layer, and electroplating control is respectively carried out on the different independent areas, so that the thickness of the metal layer obtained by electroplating in the different independent areas meets the requirement, and the thickness of the finally obtained different areas of the metal electrode is accurately controlled.)

1. An electroplating method for accurately controlling the thickness of a coating is characterized by comprising the following steps:

manufacturing a graphical seed layer on a substrate to be plated;

dividing the patterned seed layer on the substrate to be plated into at least two independent areas according to the electrode thickness distribution gradient obtained by electroplating on the non-patterned seed layer, wherein each independent area corresponds to a distribution area of a thickness interval;

manufacturing an electroplating mask pattern on the substrate to be plated and the patterned seed layer;

and sequentially electroplating metal layers on the substrate to be plated with the electroplating mask patterns and the patterned seed layer according to different independent areas to form metal electrodes.

2. The electroplating method for accurately controlling the thickness of the plated layer as claimed in claim 1, wherein in the step of dividing the patterned seed layer on the substrate to be plated into at least two independent areas according to the electrode thickness distribution gradient obtained by electroplating on the non-patterned seed layer, each independent area corresponding to a distribution area of a thickness interval, the independent areas are divided according to the following method:

and after electroplating on the non-pattern seed layer to obtain an electrode, obtaining current density distribution in the seed layer during electroplating, and arranging the at least two independent areas on the substrate according to the gradient of the current density distribution in the seed layer.

3. The electroplating method for accurately controlling the thickness of the plated layer according to claim 1, as claimed in claim 2, wherein in the step of sequentially electroplating the metal layer for different independent areas on the substrate to be plated with the electroplating mask pattern and the patterned seed layer to form the metal electrode:

the different independent areas are respectively connected with the electroplating cathodes, and the different electroplating cathodes supply different current values for the independent areas.

4. The electroplating method for accurately controlling the thickness of the plated layer as claimed in claim 2, wherein the step of sequentially electroplating metal layers for different independent areas on the substrate to be plated with the electroplating mask pattern and the patterned seed layer to form metal electrodes comprises:

separately leading out the shielded part in the patterned seed layer for carrying out the first-step electroplating operation;

and after the first-step electroplating operation is finished, carrying out second-step electroplating operation on the unmasked part of the patterned seed layer.

5. An electroplating method for accurately controlling the thickness of a plating layer according to any one of claims 1 to 4, wherein, according to the thickness distribution gradient of the electrode obtained by electroplating on the non-patterned seed layer, the patterned seed layer on the substrate to be plated is divided into at least two independent areas, and each independent area corresponds to the distribution area of one thickness interval:

the shape of each independent area is a closed figure or a semi-closed figure with any shape, wherein the closed figure comprises but is not limited to a rectangle, a circle, a trapezoid or a triangle.

6. An electroplating method with precise control over the thickness of the plated layer according to claim 5, wherein at least two independent areas of the patterned seed layer are electrically isolated from each other.

7. The electroplating method for accurately controlling the thickness of the plating layer as claimed in claim 6, wherein in the step of manufacturing the electroplating mask pattern on the substrate to be plated and the patterned seed layer:

the patterned seed layer and the electroplating mask pattern have different projections in the thickness direction.

8. The electroplating method for precisely controlling the thickness of the plated layer as recited in claim 7, wherein the step of projecting the patterned seed layer and the electroplating mask pattern in a thickness direction is different from each other comprises the steps of:

the electroplating mask pattern and the patterned seed layer are not coincident in shape and are not complementary in shape.

9. An electroplating method with precise control of the thickness of the plated layer according to any one of claims 1 to 4, further comprising the steps of:

removing the electroplating mask pattern;

and removing the patterned seed layer which is not covered by the electroplated metal layer.

10. The electroplating method for accurately controlling the thickness of the plated layer as claimed in claim 9, wherein the step of sequentially electroplating metal layers for different independent areas on the substrate to be plated with the electroplating mask pattern and the patterned seed layer to form metal electrodes comprises:

the ratio of the thickness to the width of the metal connecting line obtained by electroplating the metal layer is more than 2.

Technical Field

The invention relates to the technical field of electroplating processes of metal electrodes, in particular to an electroplating method for accurately controlling the thickness of a coating.

Background

Electroplating is a common traditional process in the fields of circuit board manufacturing, MEMS manufacturing, IC manufacturing, and the like, and is generally used for manufacturing metal interconnection structures to achieve electrical connection between elements and between layers of multilayer wiring circuits.

In most application fields, the requirement on the uniformity of the thickness of the electrode is high, the uniformity of the thickness of the electrode obtained by the existing electroplating process is poor, the thickness of the electrode in some areas is too large, and the thickness of the electrode in some areas is too small, so that the scene requirement on the uniformity of the thickness of the electrode cannot be met.

Disclosure of Invention

The embodiment of the application aims to provide an electroplating method for accurately controlling the thickness of a coating, so as to solve the technical problem that the thickness distribution of an electrode obtained by the electroplating method in the prior art is not uniform.

In order to solve the above problems, some embodiments of the present application provide an electroplating method for precisely controlling the thickness of a plating layer, comprising the steps of:

manufacturing a graphical seed layer on a substrate to be plated;

dividing the patterned seed layer on the substrate to be plated into at least two independent areas according to the electrode thickness distribution gradient obtained by electroplating on the non-patterned seed layer, wherein each independent area corresponds to a distribution area of a thickness interval;

manufacturing an electroplating mask pattern on the substrate to be plated and the patterned seed layer;

and sequentially electroplating metal layers on the substrate to be plated with the electroplating mask patterns and the patterned seed layer according to different independent areas to form metal electrodes.

In the electroplating method for accurately controlling the thickness of the plating layer provided in some embodiments of the present application, the patterned seed layer on the substrate to be plated is divided into at least two independent areas according to the electrode thickness distribution gradient obtained by electroplating on the non-patterned seed layer, and in the step of dividing each independent area into the distribution areas corresponding to one thickness interval, the independent areas are divided according to the following method:

after an electrode is obtained by electroplating on the non-pattern seed layer, the current density distribution in the seed layer during electroplating is obtained, and the at least two independent areas are arranged on the substrate according to the gradient of the current density distribution in the seed layer

In some embodiments of the present application, in the electroplating method for accurately controlling the thickness of the plating layer, a metal layer is sequentially electroplated on the substrate to be plated with the electroplating mask pattern and the patterned seed layer in sequence for different independent areas, and a metal electrode is formed in the step of:

the different independent areas are respectively connected with the electroplating cathodes, and the different electroplating cathodes supply different current values for the independent areas.

In some embodiments of the present application, in the electroplating method for accurately controlling the thickness of the plating layer, a metal layer is sequentially electroplated on the substrate to be plated with the electroplating mask pattern and the patterned seed layer in sequence for different independent areas, and a metal electrode is formed in the step of:

separately leading out the shielded part in the patterned seed layer for carrying out the first-step electroplating operation;

and after the first-step electroplating operation is finished, carrying out second-step electroplating operation on the unmasked part of the patterned seed layer.

In the electroplating method for accurately controlling the thickness of the plating layer provided in some embodiments of the present application, the patterned seed layer on the substrate to be plated is divided into at least two independent areas according to the distribution gradient of the thickness of the electrode obtained by electroplating on the non-patterned seed layer, and each independent area corresponds to a distribution area of a thickness interval:

the shape of each independent area is a closed figure or a semi-closed figure with any shape, wherein the closed figure comprises but is not limited to a rectangle, a circle, a trapezoid or a triangle.

According to the electroplating method for accurately controlling the thickness of the plating layer, provided in some embodiments of the application, at least two independent areas of the patterned seed layer are electrically insulated.

In some embodiments of the present application, in the step of forming the plating mask pattern on the substrate to be plated and the patterned seed layer, the plating method for accurately controlling the thickness of the plating layer includes:

the patterned seed layer and the electroplating mask pattern have different projections in the thickness direction.

In some embodiments of the present application, the electroplating method for precisely controlling the thickness of the plating layer, wherein the step of projecting the patterned seed layer and the electroplating mask pattern in the thickness direction differently includes:

the electroplating mask pattern and the patterned seed layer are not coincident in shape and are not complementary in shape.

The electroplating method for accurately controlling the thickness of the coating provided by some embodiments of the application further comprises the following steps:

removing the electroplating mask pattern;

and removing the patterned seed layer which is not covered by the electroplated metal layer.

In some embodiments of the present application, in the electroplating method for accurately controlling the thickness of the plating layer, a metal layer is sequentially electroplated on the substrate to be plated with the electroplating mask pattern and the patterned seed layer in sequence for different independent areas, and a metal electrode is formed in the step of: the ratio of the thickness to the width of the metal connecting line obtained by electroplating the metal layer is more than 2.

Compared with the prior art, the technical scheme provided by the application at least has the following beneficial effects: according to the electrode thickness distribution gradient obtained by electroplating on the non-pattern seed layer, the pattern seed layer on the substrate to be plated is divided into at least two independent areas, and electroplating control can be respectively carried out on different independent areas when electroplating is carried out, so that the thickness of the metal layer obtained by electroplating in different independent areas meets the requirement, and the thickness of the finally obtained different areas of the metal electrode is accurately controlled.

Drawings

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

FIG. 1 is a flow chart illustrating the steps of an electroplating method for precisely controlling the thickness of a coating according to one embodiment of the present application;

FIGS. 2a-2e are schematic structural diagrams of a plated part at various stages during the execution of an electroplating method for accurately controlling the thickness of a plated layer according to an embodiment of the present application;

FIGS. 3 a-3 d are schematic views of the structure of the electroplating part at various stages in the process of forming a patterned seed layer according to an embodiment of the present disclosure;

FIGS. 4 a-4 c are schematic views of the structure of an electroplating assembly at various stages of an execution process for forming a patterned seed layer according to another embodiment of the present disclosure;

FIG. 5 is a schematic structural diagram of a metal electrode prepared by an electroplating method for accurately controlling the thickness of a plating layer according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of a metal electrode prepared by an electroplating method for accurately controlling the thickness of a plating layer according to another embodiment of the present application.

Detailed Description

In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only used for convenience of description of the present application, and do not indicate or imply that the device or component being referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; the two components can be directly connected or indirectly connected through an intermediate medium, and the two components can be communicated with each other. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

The present embodiment provides an electroplating method for precisely controlling the thickness of a plating layer, as shown in fig. 1 and fig. 2a to 2e, comprising the steps of:

the method comprises the following steps: and manufacturing a patterned seed layer 2 on the substrate 1 to be plated. The substrate 1 to be plated may be a substrate including a functional element or a circuit, and the method for manufacturing the patterned seed layer 2 may select a deposition method, such as a chemical vapor deposition method.

Step two: according to the electrode thickness distribution gradient obtained by electroplating on the seed layer without patterns, the patterned seed layer 2 on the substrate 1 to be plated is divided into at least two independent areas, wherein an area a, an area b, an area c, an area d and an area e are taken as examples in fig. 2c for illustration, and each independent area corresponds to a distribution area of a thickness interval. Since the division of the independent areas is performed according to the thickness distribution result of the plating electrode without the patterned seed layer, the actual shape is related to the thickness distribution result of the plating electrode, and it is advantageous to use the electrode distribution area with the first thickness value as the area a and the electrode distribution area with the second thickness value as the area b, in this case, the area a may also be a ring shape surrounding the periphery of the area b, and preferably, the shape of each of the independent areas is a closed pattern or a semi-closed pattern with any shape, wherein the closed pattern includes, but is not limited to, a rectangle, a circle, a trapezoid or a triangle, so the division result of the independent areas in fig. 2c is only a matter of description.

Step three: and manufacturing an electroplating mask pattern 3 on the substrate 1 to be plated and the patterned seed layer 2.

Step four: and sequentially electroplating a metal layer 4 on the substrate 1 to be plated with the electroplating mask pattern 3 and the patterned seed layer 2 aiming at different independent areas to form a metal electrode. Because the thickness of the electroplating electrode of the non-pattern seed layer corresponding to different independent areas is different, in the scheme, when electroplating is carried out on different independent areas, the electroplating conditions of the different independent areas are respectively controlled, so that the thickness of the metal electrode obtained after electroplating of each independent area meets the actual requirement.

In the second step, the independent areas may be divided as follows: and after electroplating on the non-pattern seed layer to obtain an electrode, obtaining current density distribution in the seed layer during electroplating, and arranging the at least two independent areas on the substrate according to the gradient of the current density distribution in the seed layer. The current density of the seed layer has a certain corresponding relation with the thickness of the electroplating electrode, so that the distribution condition of the thickness of the electrode can be determined by adopting a mode of detecting the current density of the seed layer. In the electrode thickness gradient distribution, the difference value between different thickness gradients can be selected according to empirical values, and the gradients are divided according to the requirement of application occasions on the uniformity of the electrode thickness.

In some embodiments, step four may be implemented as follows: the different independent areas are respectively connected with the electroplating cathodes, and the different electroplating cathodes supply different current values for the independent areas. By adopting the scheme, different current values can be supplied by different electroplating cathodes, and the electroplating process can be completed by executing the mode of electroplating once.

In other embodiments, step four may be implemented as follows: separately leading out the shielded part in the patterned seed layer for carrying out the first-step electroplating operation; and after the first-step electroplating operation is finished, carrying out second-step electroplating operation on the unmasked part of the patterned seed layer. That is, the plating operation can be performed for different regions respectively for different times, which enables the thickness of the metal electrode to be obtained with good uniformity. In some embodiments, the same or different plating currents may be used to perform the fractional plating.

As shown in fig. 3 a-3 d, in some embodiments, a patterned seed layer 2 can be formed on a substrate 1 to be plated by:

step A: depositing a seed layer 21 on the substrate 1 to be plated; the material of the seed layer 21 may be at least one of palladium, titanium, nickel, copper, gold and silver, or an alloy material containing at least one of palladium, titanium, nickel, copper, gold and silver. The seed layer 21 may be deposited by physical vapor deposition, chemical vapor deposition, electroplating, electroless plating, or the like.

And B: manufacturing a seed layer mask pattern 2A on the seed layer 21; the mask can be made of photoresist or hard mask material. The photoresist comprises at least one of photoresist and dry film photoresist, and the hard mask material comprises at least one of silicon, silicon oxide, silicon nitride and silicon oxynitride.

And C: and etching the seed layer 21 with the seed layer mask pattern 2A to expose the substrate 1 to be plated, and reserving the seed layer 21 on the substrate 1 to be plated in the coverage area of the seed layer mask pattern 2A to form the patterned seed layer 2.

As shown in fig. 4 a-4 c, in some embodiments, a patterned seed layer 2 can be formed on a substrate 1 to be plated by:

step D: and manufacturing a seed layer mask pattern 2B on the substrate 1 to be plated. The mask can be made of photoresist or hard mask material. The photoresist comprises at least one of photoresist and dry film photoresist, and the hard mask material comprises at least one of silicon, silicon oxide, silicon nitride and silicon oxynitride.

Step E: and depositing a seed layer 22 on the substrate to be plated 1 with the seed layer mask pattern 2B. Physical vapor deposition, chemical vapor deposition, electroplating, electroless plating, and the like may be used. The material of the seed layer can be at least one of palladium, titanium, nickel, copper, gold and silver, or an alloy material containing at least one of palladium, titanium, nickel, copper, gold and silver.

Step F: and removing the seed layer mask pattern 2B to expose the substrate 1 to be plated, and reserving the seed layer 22 in the region of the substrate to be plated covered by the seed layer-free mask pattern 2B to form the pattern seed layer 2.

In some embodiments, as shown in fig. 2d, the patterned seed layer 2 and the plating mask pattern 3 have different projections in the thickness direction. Further, the different projection of the patterned seed layer 2 and the electroplating mask pattern 3 in the thickness direction comprises: the shapes of the electroplating mask pattern 3 and the patterned seed layer 2 are not overlapped; and the electroplating mask pattern 3 is not complementary to the patterned seed layer 2.

In some aspects, it is preferable that the material of the metal layer 4 is at least one of palladium, titanium, nickel, copper, gold, and silver; or an alloy material containing at least one of palladium, titanium, nickel, copper, gold, and silver. Further preferably, the metal layer 4 is the same material as the patterned seed layer 2.

In some aspects, the at least two discrete regions of the patterned seed layer are electrically isolated from each other. Based on the foregoing principle, the seed layer is divided into at least two electrically isolated independent regions according to the current density distribution of the seed layer or the gradient distribution of the electrode thickness. Namely, when the conventional electroplating process is carried out on the seed layer without the pattern of the existing plated substrate, the thickness of the obtained electrode can be divided into a plurality of grades, the patterned seed layer on the substrate 1 to be plated is divided into different types of areas according to different grades, and the electroplating conditions of different areas are respectively set, so that the thickness of the metal electrode obtained by final electroplating can have better uniformity.

Preferably, in some embodiments, the electroplating method for precisely controlling the thickness of the plating layer may further include the following steps:

step four: the plating mask pattern 3 is removed from the structure shown in fig. 2e, and the resulting structure is shown in fig. 5.

Step five: the excess patterned seed layer in fig. 5 is removed, and only the seed layer 23 covered by the metal layer 4 remains, so that the structure of the metal electrode is shown in fig. 6.

By adopting the scheme in the embodiment of the application, the thickness uniformity of the finally obtained metal electrode can be adjusted by modifying the substrate to be plated and the seed layer, so that the current density distribution in the seed layer near the electrode is also uniform.

In some preferred embodiments, in step four, the ratio of the thickness to the width of the metal line obtained by electroplating the metal layer is greater than 2. Preferably, the ratio of the thickness to the width of the metal connecting line can be more than 3, and even can reach 5 or 10 and the like. In the application, the electroplating mask pattern 3 is manufactured on the substrate 1 to be plated and the patterned seed layer 2, the ratio of the depth to the width of the groove of the electroplating mask pattern 3 can be larger than 3 or larger, then the groove of the electroplating mask pattern 3 is filled with a metal material, and the filled thickness can be set according to requirements, so that the ratio of the thickness to the width of the metal connecting line meets the requirements. The metal electrode obtained by the scheme can finally realize that the ratio of the whole thickness to the whole width is more than 2 and even can reach 10 or 20, and the metal electrode prepared by the method can greatly improve the bandwidth of a photoelectronic device.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.