JP3275487B2 - Plating apparatus and plating method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating apparatus and a plating method, and more particularly to a jet-type plating apparatus and a plating method for performing high-quality and high-speed electroplating. The plating apparatus and method of the present invention are particularly suitable for performing fine plating such as forming electrode bumps on a semiconductor wafer.

[0002]

2. Description of the Related Art Conventionally, for example, several tens of
As a method of forming an electrode bump having a size of about several hundreds of micrometers at a high speed, a jet flow method is adopted (Japanese Patent Laid-Open No.
No. 6-152991). In the jet-type electroplating method, a semiconductor wafer is placed in a plating cell with its surface to be plated facing down, and the plating solution contained in the circulation tank is pumped by a pump and applied as a jet to the surface to be plated. This is a method of performing electroplating.

A method of obtaining a uniform plating film thickness distribution within a substrate to be plated (in a surface to be plated) in a jet type electroplating apparatus has been proposed (Japanese Patent Laid-Open No. 2-6).
1089, JP-A-3-247792, etc.). However, these conventional methods require a complicated mechanism such as providing a large number of nozzles for blowing out a plating solution or swinging the nozzle groups, and there has been a problem that a significant increase in cost of the apparatus cannot be avoided.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a jet-type plating apparatus and a plating method which can improve the uniformity of a plating film thickness without requiring a complicated mechanism.

[0005]

In order to achieve the above object, a plating apparatus according to the present invention is a plating apparatus for performing electroplating by jetting a plating solution onto a surface of a substrate to be plated. One end face of the cylindrical body having a large cross section is also closed by a substrate to be plated holding member, and a plating solution outlet is arranged on the side wall of the cylindrical body along the outer edge of the one end face, and the cylindrical body The other end face is provided with an electroplating cell provided with a plating solution inlet, and the one end face is closed with a reference plating substrate larger than the cross section of the cylindrical body in place of the holding member to perform plating. In the recessed region on the holding member set corresponding to the plating film thickness uniform region surrounded by the annular region where the plating film thickness is peaked, and the plating surface is the same as the holding member. So that Characterized by being adapted to hold the substrate.

Further, the plating method using the apparatus of the present invention is a plating method in which a plating solution is jetted onto a surface of a substrate to be plated to perform electroplating. One end face of the body is closed with a substrate to be plated holding member, a plating solution outlet is arranged on the side wall of the tubular body along the outer edge of the one end face, and a plating solution is provided on the other end face of the tubular body. Using an electroplating cell provided with an inflow port, the plating film thickness peaks when the one end face is closed and plated with a reference plating substrate larger than the cross section of the cylindrical body instead of the holding member. The substrate to be plated is placed in a recessed region on the holding member set corresponding to the plating film thickness uniform region surrounded by the annular region to be formed, and the plating surface is the same as the holding member. Specially to hold To.

In the present invention, a plurality of substrates to be plated can be held and plated simultaneously in a region on the holding member set corresponding to the region having a uniform plating film thickness.

[0008]

The present inventor has found that in jet-type electroplating, the distribution of the plating film thickness has a specific form consisting of an annular film thickness peak region and a film thickness uniform region surrounded by the region. The present invention utilizes this unique plating film thickness distribution mode, and performs plating in a state where the surface to be plated is included in the above-mentioned uniform plating film thickness region, thereby achieving uniform plating over the entire surface to be plated. A film thickness can be obtained. For this purpose, a cylindrical plating cell having a cross section larger than that of the substrate to be plated is used, and one end face of the cylindrical cell is closed by a substrate holding member to be plated. A plating solution outlet is arranged on the side wall of the cylindrical body along the outer edge of the end face. A plating solution inflow port is provided on the other end surface of the cylindrical cell, and the plating solution is supplied from outside. The jet of the plating solution supplied from the inflow port into the cell is supplied to the surface to be plated of the substrate to be plated held on the one end surface.

The substrate to be plated is held in a recess of the holding member closing one end surface of the cell so that the surface to be plated is flush with the holding member. As a result, a plating solution flow equivalent to that when one end face of the cell is closed with a large substrate to be plated covering the entire cross section of the cell is formed. The plating film thickness distribution formed on the large substrate to be plated by the plating solution flow is obtained in advance by an experiment. Based on the plating thickness distribution obtained in this experiment, a concave region is provided on the holding member surface in correspondence with the plating thickness uniform region located inside the annular plating thickness peak region. By performing plating while holding the substrate to be plated in the recess, the uniformity of the plating film thickness can be easily improved.

[0010]

【Example】

Embodiment 1 FIG. 1 (b) is a cross-sectional view of a jet-type electrolytic plating apparatus according to the present invention. One end surface of the cylindrical plating cell 12 through which the plating solution flows is held by the plated substrate holder 11.
Is closed. The plating solution is a cylindrical cell 12
After flowing upward from below, it hits the substrate holder 11 and changes its direction, flows radially as indicated by the arrow 14, and flows through the plating solution outlet 13 provided at the top of the cylindrical cell 12. It flows out of the cell 12. The outlets 13 are arranged along the outer edge of the upper end of the cylindrical cell 12.

FIG. 1 (a) shows, separately from this, a cylindrical cell 12 obtained by plating the same end face of the cell 12 with a substrate to be plated having a size to cover the entire cross section. 3 shows the distribution of the plating film thickness in the diameter direction of FIG. Due to the non-uniform flow of the plating solution, the thickness distribution of the plating film in the central portion and the outer edge portion becomes thinner, and an annular film thickness peak region exists immediately inside the outer edge. In the conventional jet-type electroplating, the substrate holder 1
In this manner, one end surface of the cylindrical cell 12 was closed with one substrate to be plated itself without using the substrate 1. Therefore, the film thickness distribution shown in FIG. 1A occurred in the surface of the substrate to be plated. On the other hand, in the jet flow plating apparatus of the present invention, the diameter of the cylindrical cell 12 is made larger than the diameter of the substrate to be plated, and the substrate 16 to be plated is further moved by using the substrate holder 11 shown in FIG. By arranging in the thickness uniformity range 15 of (a), the uniformity of the film thickness distribution in the surface of the substrate 16 to be plated can be improved.

The holder 11 has a power supply electrode 17 for performing electroplating on the substrate to be plated. In order to prevent the plating metal from adhering to the power supply electrode 17, the holder 11 contacts the substrate 16 from a position corresponding to the inner wall of the cell 12. The connection point extends to the inside of the holder 11 so that the power supply electrode 17 is not exposed to the plating solution. The holder 11 is provided with a concave portion having the shape of the substrate 16 at a portion where the substrate 16 is to be mounted, so that the surface of the substrate holder 11 and the surface of the substrate 16 are at the same height. Thereby, the flow of the plating solution can be made uniform, and the plating film thickness distribution can be improved.

FIG. 2 is an overall configuration diagram of the jet plating apparatus of the present invention shown in FIG. One end of the cylindrical cell 12 is covered and closed with the holder 11 having the substrate 16 to be plated mounted thereon,
An anode (anode) 27 is provided in the cylindrical cell 12 so as to face the substrate 16 to be plated. The plating solution 23 in the container 24 is sucked by the pump 25 and introduced into the lower part of the cylindrical cell 12. Plating solution 2 introduced into lower part of cylindrical cell 12
Reference numeral 3 denotes a plating solution outlet 1 provided above the cylindrical cell 12 through a plurality of through holes provided in the anode 27 and hitting the substrate 16 mounted in the recess of the substrate holder 11.
From 3 flows into the container 24. The electrolytic plating is performed by applying a constant current between the power supply electrode provided on the surface of the substrate 16 to be plated and the anode 27.

Embodiment 2 FIG. 3 is a schematic sectional view showing an embodiment in which the plating apparatus of the present invention is used for plating a plurality of substrates to be plated. The apparatus of FIG. 3 has a configuration in which a jig 31 covers a cylindrical cell 32 through which a plating solution flows. A plurality of substrates 33 to be plated are mounted on the jig 31.
A constant current is applied to the surface through the power supply electrode 34. After the plating solution flows upward from below the cylindrical cell 32, the plating solution strikes the substrate holder 31, changes the direction of the flow, and flows radially as indicated by the arrow 36, and the plating solution provided at the upper part of the cylindrical cell 32. The liquid flows out of the cylindrical cell 32 from the liquid outlet 35. The outlets 35 are arranged along the outer edge of the upper end of the cell 32.

By making the diameter of the cylindrical cell 32 sufficiently larger than the diameter of the substrate 33 to be plated, the uniform range of the plating film thickness can be widened.
3 can be performed simultaneously, and the throughput is improved.

[0016]

As described above, according to the present invention,
In jet electroplating, a uniform mechanism of the plating film thickness can be improved without requiring a complicated mechanism.

[Brief description of the drawings]

FIG. 1 (a) is a graph showing a plating film thickness distribution,
(b) is a sectional view showing the vicinity of the upper end of the plating cell of the jet electroplating apparatus according to the present invention.

FIG. 2 is a sectional view showing the entire plating apparatus of FIG. 1;

FIG. 3 is a sectional view showing the vicinity of the upper end of a plating cell of a jet-type electroplating apparatus for simultaneously electroplating a plurality of substrates to be plated according to the present invention.

[Explanation of symbols]

 16, 33 ... substrate to be plated 11, 31 ... holder for substrate to be plated 13, 35 ... outlet for plating solution 12, 32 ... electroplating cell 15 ... region with uniform plating film thickness

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshiki Ueno 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB name) C25D 17/00 C25D 5/08 C25D 7/12

Claims (4)

(57) [Claims] 1. A plating apparatus for performing electroplating by jetting a plating solution onto a surface to be plated of a substrate to be plated, wherein one end surface of a cylindrical body having a cross section larger than that of the substrate to be plated (16, 33) is provided. The plating solution outlets (13, 35) are arranged on the side wall of the tubular body along the outer edge of the one end face, and are closed by the substrate holding members (11, 31), and the other end face of the tubular body is closed. An electroplating cell (12, 32) provided with a plating solution inlet is provided, and instead of the holding member (11, 31), the one of the reference plated substrates larger than the cross section of the cylindrical body is used as the reference plating target substrate. When the plating is performed with the end face closed, the plating film thickness is in the concave region on the holding member (11, 31) set in correspondence with the plating film thickness uniform region (15) surrounded by the annular region where the plating film has a peak. And holding the substrate to be plated (16, 33) so that the surface to be plated is flush with the holding member. Plating apparatus characterized by a. 2. A plurality of substrates to be plated (33) are held and plated simultaneously in a region on the holding member (31) set corresponding to the plating film thickness uniform region (15). The plating apparatus according to claim 1, wherein: 3. A plating method for performing electroplating by jetting a plating solution onto a surface to be plated of a substrate to be plated, wherein one end surface of a cylindrical body having a cross section larger than that of the substrate to be plated is provided. The plating solution outlets (13, 35) are arranged on the side wall of the tubular body along the outer edge of the one end face, and are closed by the substrate holding members (11, 31), and the other end face of the tubular body is closed. An electroplating cell (12, 32) provided with a plating solution inlet is used for the reference plating substrate larger than the cross section of the cylindrical body in place of the holding member (11, 31). When the plating is performed with the end face closed, the plating film thickness is in the concave region on the holding member (11, 31) set in correspondence with the plating film thickness uniform region (15) surrounded by the annular region where the plating film has a peak. And holding the substrate to be plated (16, 33) such that the surface to be plated is flush with the holding member. Plating method to butterflies. 4. A plurality of substrates to be plated (33) are held and plated simultaneously in a region on the holding member (31) set corresponding to the plating film thickness uniform region (15). The plating method according to claim 3 , wherein