CN113718308A

CN113718308A - Wafer double-side electroplating device and process

Info

Publication number: CN113718308A
Application number: CN202111012475.9A
Authority: CN
Inventors: 严立巍; 符德荣; 文锺; 陈政勋
Original assignee: Zhejiang Tongxinqi Technology Co ltd
Current assignee: Zhejiang Tongxinqi Technology Co ltd
Priority date: 2021-08-31
Filing date: 2021-08-31
Publication date: 2021-11-30

Abstract

The invention discloses a wafer double-sided electroplating device and a process, wherein the wafer double-sided electroplating device comprises an electroplating bath, a clamp, an anode plate and a compensation plate, the compensation plate is arranged between the anode plate and the clamp, the compensation plate is connected with the electroplating bath in a sliding manner, a plurality of compensation holes are formed in the surface of the compensation plate, the compensation holes are arranged in a rectangular array, and the diameters of the compensation holes are gradually reduced from the middle to the upper side and the lower side. The compensation plate is driven by the driving device to do simple harmonic motion along the Y axis and the Z axis, the compensation plate actually moves along an elliptical or circular track after the simple harmonic motion in the two directions is synthesized, the forming speed of the metal layer of the plated surface tends to be balanced through the obstruction of the compensation plate, so that a relatively flat plated film is obtained, and the problem of uneven metal thickness in the wafer electroplating process in the prior art is solved.

Description

Wafer double-side electroplating device and process

Technical Field

The invention relates to the technical field of wafer processing, in particular to a wafer double-side electroplating device and a wafer double-side electroplating process.

Background

In the production process of semiconductor integrated circuits, a metal layer is formed on the surface of a wafer by electroplating. Wafer electroplating is one of the key links in the semiconductor wafer manufacturing process, and the production efficiency and electroplating quality of the process are of great importance. The process is to put the wafer in the plating solution, connect negative voltage as cathode on the wafer, connect positive voltage to anode in the plating solution, and deposit the metal ions in the plating solution on the surface of the wafer by the action of electric field. With the development of the semiconductor industry, the demand for the use degree of wafers is higher and higher, and the electroplating of the wafers is also developed from single-sided electroplating to double-sided electroplating.

The chinese patent publication No. CN109972190A discloses a wafer double-sided electroplating device and an electroplating method, in which the wafer to be plated is used as a cathode and disposed between a first anode plate and a second anode plate, so as to perform double-sided electroplating on the wafer to be plated, and the distance between the first anode plate and the second anode plate and the wafer to be plated is changed, so as to change the current density borne by the wafer to be plated, achieve the current distributable function at two sides of a single power supply wafer, and further obtain coatings with different thicknesses. Although the wafer double-sided electroplating device and the method provided by the invention realize the double-sided electroplating of the wafer, the problem of uneven metal thickness on the surface of the wafer can occur during electroplating because the current distribution is uneven during electroplating (as shown in fig. 4), the plating layer is thicker at the edge of the plated surface of a circuit board because the equipotential planes are distributed densely, and the plating layer is thinner in the middle of the plated piece because the equipotential planes are distributed sparsely.

Disclosure of Invention

In order to solve the above-mentioned drawbacks in the background art, the present invention provides a device and a process for double-sided electroplating of a wafer, wherein a compensation plate is driven by a driving device to perform simple harmonic motion along two directions, namely a Y axis and a Z axis, the compensation plate actually moves along an elliptical or circular track after the simple harmonic motion in the two directions is synthesized, and the forming speed of a plated metal layer tends to be balanced through the obstruction of the compensation plate, so that a relatively flat plated film is obtained, and the problem of uneven metal thickness in the wafer electroplating process in the prior art is solved.

The purpose of the invention can be realized by the following technical scheme:

a wafer double-sided plating apparatus, comprising:

the electroplating bath is a cuboid groove body and is filled with electroplating solution;

the clamp is annular and is arranged in the middle of the electroplating bath and is connected with the cathode of the power supply;

two anode plates are arranged on two sides of the clamp symmetrically, the anode plates are connected with the electroplating bath in a sliding manner, and the anode plates are connected with the positive electrode of the power supply;

the compensation plate is arranged between the anode plate and the clamp and is in sliding connection with the electroplating bath, a plurality of compensation holes are formed in the surface of the compensation plate, the compensation holes are arranged in a rectangular array, and the diameters of the compensation holes are gradually decreased from the middle to the upper side and the lower side in sequence.

Further preferably, the compensation plate is driven by the driving device to make simple harmonic motion along the Y axis and the Z axis, the compensation plate actually moves along an elliptical or circular track after the simple harmonic motion in the two directions is synthesized, and the forming speed of the plated metal layer tends to be balanced through the obstruction of the compensation plate.

A wafer double-side electroplating method comprises the following steps:

s1, fixing the wafer to be plated on the clamp, and then adjusting the distance between the two anode plates and the wafer to be plated;

s2, injecting electroplating solution into the electroplating bath and introducing inert gas;

s3, connecting the clamp to the cathode of an electroplating power supply, connecting the two anode plates to the anode of the electroplating power supply, and switching on the power supply to start electroplating;

and S4, driving the compensation plate to do simple harmonic motion through the driving device during electroplating, and enabling the forming speed of the plated surface metal layer to be balanced through the obstruction of the compensation plate to obtain a relatively flat plated film.

The invention has the beneficial effects that:

the compensation plate is driven by the driving device to do simple harmonic motion along the Y axis and the Z axis, the compensation plate actually moves along an elliptical or circular track after the simple harmonic motion in the two directions is synthesized, the forming speed of the metal layer of the plated surface tends to be balanced through the obstruction of the compensation plate, so that a relatively flat plated film is obtained, and the problem of uneven metal thickness in the wafer electroplating process in the prior art is solved.

Drawings

The invention will be further described with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a wafer double-side electroplating apparatus according to the present invention;

FIG. 2 is a schematic view of the construction of the compensation plate of the present invention;

FIG. 3 is a schematic diagram of the motion trajectory of the compensation plate of the present invention;

FIG. 4 is a graph showing a current distribution between an anode and a cathode during electroplating.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "opening," "upper," "lower," "thickness," "top," "middle," "length," "inner," "peripheral," and the like are used in an orientation or positional relationship that is merely for convenience in describing and simplifying the description, and do not indicate or imply that the referenced component or element must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be considered as limiting the present invention.

As shown in fig. 1-2, a wafer double-side electroplating apparatus includes:

As shown in FIG. 3, the compensation plate is driven by the driving device to make simple harmonic motion along the Y-axis and Z-axis, the compensation plate actually moves along an elliptical or circular track after the simple harmonic motion in the two directions is synthesized, and the forming speed of the plated metal layer tends to be balanced through the obstruction of the compensation plate.

A wafer double-side electroplating method based on the wafer double-side electroplating device comprises the following steps:

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed.

Claims

1. A wafer double-side electroplating device is characterized by comprising:

2. The wafer double-sided plating device of claim 1, wherein the compensation plate is driven by a driving device to move in a simple harmonic manner along both directions of a Y axis and a Z axis.

3. A wafer double-sided electroplating method based on the wafer double-sided electroplating device of claim 1 is characterized by comprising the following steps: