Patent Application
20150068890
The present invention relates to a plating jig and a plating device used for substrate plating processing, and more particularly to a plating jig for forming a plating film on a fine wiring groove, a hole, and a resist opening portion formed on a surface to be plated of a semiconductor wafer and the like or for forming a bump (projecting electrode) which electrically connects a semiconductor chip and a substrate to each other on a surface to be plated of a semiconductor wafer, and a plating device which uses the plating jig.
In general, an electrolytic plating method is roughly classified into a jet-type or cup-type plating method where plating is performed such that a substrate such as a semiconductor wafer or the like is horizontally placed with a surface to be plated of the substrate facing down, and a plating solution is jetted from below, and a dip-type plating method where plating is performed such that a substrate is vertically disposed in an erected manner in a plating bath, a plating solution is jetted into the plating bath from below the plating bath, the substrate is immersed in the plating solution in the plating bath while allowing the overflow of the plating solution from the plating bath. The reason why plating is performed with the substrate disposed in a vertically erected manner in the dip-type electrolytic plating method is that bubbles generated on the surface to be plated of the substrate can be easily removed and that it is possible to make it difficult for particles or the like adhere to the surface to be plated of the substrate. In this manner, with the use of the electrolytic plating method where plating is performed with the substrate disposed in a vertically erected manner, babbles which are formed by a vigorous reduction action at the time of performing high-speed plating can be easily removed. Accordingly, this electrolytic plating method is desirable.
An electrolytic plating device which adopts the above-mentioned conventional dip-type electrolytic plating method includes a substrate holder which holds a substrate such as a semiconductor wafer in a detachable manner in a state where outer peripheral edge surfaces and a back surface of the substrate are sealed and a front surface (a surface to be plated) is exposed, and the surface to be plated of the substrate is plated by immersing the substrate holder into a plating solution together with the substrate.
However, in such a conventional electrolytic plating method which adopts dip-type plating, the substrate is immersed while holding the substrate in a vertically erected state in the plating solution, and the plating solution is made to flow in the upward direction from a lower portion of the plating bath. Accordingly, the plating solution jetted into the plating bath is always supplied toward an upper portion from a lower portion of the surface to be plated of the substrate and hence, a flow speed of the plating solution becomes non-uniform between the upper portion and the lower portion of the surface to be plated of the substrate thus giving rise to a drawback that a delicate difference occurs in film thickness of plating depending on a place of the surface to be plated of the substrate. Further, non-uniformity of current density also becomes a factor which causes non uniformity of plating.
To overcome such drawbacks, patent literatures 1, 2 disclose a plating method and a plating device where a substrate holder which holds a substrate such as a semiconductor wafer is rotated in a plating bath by a drive unit so that non-uniformity in flow speed or non-uniformity in current density of a plating solution are eliminated whereby the uniformity of a plating film thickness is increased.
However, as in the case of a plating method such as the plating method disclosed in patent literature (PTL) 1 where a shaft is connected to the substrate holder in a state where the shaft from the drive unit arranged outside the plating bath penetrates a side wall of the plating bath, sealing treatment of a penetrating portion arises as a problem to be solved. To cope with this drawback, in the method disclosed in PTL 1, sealing treatment is not applied to the penetrating portion intentionally such that the shaft and the side wall of the plating bath are brought into a non-contact state from each other, and a plating solution flows out through a gap formed between the shaft and the side wall. Such constitution, however, requires the modification of the plating bath. On the other hand, in the plating method disclosed in PTL 2, a drive shaft is arranged at a predetermined angle and hence, the drive shaft does not penetrate a side wall of a plating bath. However, it is necessary to modify the plating bath itself eventually including the arrangement of an anode plate at a predetermined angle so as to make an anode plate face an object to be plated or the formation of a bottom portion of the plating bath along an angle of the shaft.
PTL 1: JP-A-2004-300462
PTL 2: JP-A-2002-327291
Accordingly, the present invention has been made to overcome such drawbacks of the conventional plating device, and it is an object of the present invention to provide a plating jig which includes a rotation drive unit for rotatably driving a substrate holder and is detachably mountable on a plating bath without modifying the plating bath, and a plating device which utilizes the plating jig.
The present invention has been made to overcome the above-mentioned drawbacks, and provides a plating jig which is characterized by including: a support portion formed in an engageable manner with a side wall of a plating bath; and a substrate holder mounted on the support portion in a vertically rotatable manner, wherein the plating jig further includes a rotary means for rotating the substrate holder.
The present invention also provides a plating device which is characterized in that the plating jig is engageable with the side wall of the plating bath, and a paddle which is movable in a reciprocating manner in the lateral direction is arranged between the substrate holder and an anode plate which faces the substrate holder in an opposed manner.
According to the plating jig of the present invention, the plating jig can be easily mounted on the plating device by merely making the plating jig engage with the side wall of the plating bath, a plating solution flow is used as a rotary drive unit for rotating the substrate holder, or power of a drive part is transmitted to the substrate holder by way of a rotary shaft or a gear member. None of these provisions requires the modification of the plating bath.
Further, according to the plating device provided with the plating jig of the present invention which is also provided with the paddle for agitation between the substrate holder and the anode plate, a plating solution flow which flows along a surface to be plated of the substrate can be made uniform also by the agitation generated by the paddle in addition to the rotation of the plating jig and hence, it is possible to form a plating film having a more uniform film thickness.
In the case where the plating device provided with the plating jig of the present invention is also provided with a plating solution jetting port on a bottom portion of the plating bath disposed below the substrate holder, a rotational force can be generated more efficiently by providing a difference in strength of the plating solution flow between left and right sides of the substrate holder.
(b) A front view of the outer frame member of the plating jig of the present invention.
(b) A front view of the outer frame member of the plating jig of the present invention.
(b) A front view of the outer frame member of the plating jig of the present invention.
(b) A view showing a different mode of the blade portion of the outer frame member of the plating jig of the present invention.
Hereinafter, embodiments of a plating jig of the present invention and a plating device which uses the plating jig are explained in detail by reference to drawings. The present invention is not particularly limited to the embodiments.
As shown in the drawings, the plating jig 2 of the present invention is constituted of: the support portion 40 which is formed in an engageable manner with the side wall of the plating bath; and the substrate holder 30 which is rotatably mounted on the support portion 40. The respective portions are explained in detail by reference to
The substrate holder 30 is constituted of: the holding member 31; the sealing member 32; the outer frame member 33; the shaft portion 34; and the fixing bolts 35, 36, 37. Among these components, with respect to the holding member 31, on an upper surface of the base portion 311 formed in a disc shape, the substrate mounting surface 312 having a diameter smaller than a diameter of the base portion 311 is mounted in a projecting manner. The substrate mounting surface 312 has the substantially same shape and size as the substrate W to which plating is applied. A plurality of first electricity supply members 314 are mounted on the base portion 311 around the substrate mounting surface 312 in a projecting manner. Further, the hole portion 313 into which the shaft portion 34 can be inserted is formed in a center portion of the substrate mounting surface 312.
The sealing member 32 is formed into an annular shape having the substantially same diameter as the holding member 31, and the opening portion 321 of the sealing member 32 is formed with an inner diameter slightly smaller than an outer diameter of the substrate W. On a surface of the sealing member 32 which faces the holding member 31 in an opposed manner, an annular-shaped seal packing 322 and a second electricity supply member 323 (not shown in
The outer frame member 33 is constituted of two members consisting of semi-annular left and right members. The outer frame member 33 has an approximately U-shaped cross section. At the time of assembling the substrate holder 30, the outer frame member 33 is fitted on outer peripheral edges of the holding member 31 and the sealing member 32. To be more specific, two outer frame members 33 are mounted on the outer peripheral edges of the holding member 31 and the sealing member 32 from left and right sides, and the outer frame members 33 are fastened and fixed to each other at upper and lower connecting portions 331 using bolts or the like. In the plating jig 2 shown in
The substrate holder 30 is mounted on the support portion 40 such that the shaft portion 34 having a threaded portion is inserted into the hole portion 313 formed in the holding member 31 and the hole portion 41 formed in the support portion 40, and the fixing bolts 35, 36, 37 are threadedly engaged with the threaded portion of the shat portion 34 thus fixing the substrate holder 30 to the support portion 40. In this case, it is desirable to seal the fixing bolt 36 which are exposed to a plating solution by applying coating or the like to the fixing bolt 36 after the bolt 36 is fixed to the shaft portion 34. Although the fixing bolt 37 is exposed to the plating solution in the same manner as the fixing bolt 36, it is desirable to form recessed portions into which the fixing bolt 37 can be embedded on a back surface of the support portion 40 as shown in
Further, a method of mounting the substrate holder 30 on the support portion 40 which differs from the above-mentioned method is explained hereinafter. Firstly, the support portion 40 is formed such that the support portion 40 is split into two parts as viewed from a front side, that is, left and right members, and the recessed portion in which the shaft portion 34 and the fixing bolt 37 can be embedded is formed on the left and right members respectively. Then, the shaft portion 34 on which the fixing bolt 37 is preliminarily mounted is arranged on either one of the left and right members of the support portion 40 having the split structure, and the other member of the support portion 40 is abutted and fixed to one member thus finishing the mounting of the substrate holder 30 on the support portion 40. Due to such a mounting method, the whole length of the shaft portion 34 can be further shortened and, at the same time, as described above, it is unnecessary to seal the opening portion formed on a back side of the support portion 40.
Next, a method of supplying electricity to the substrate W is explained. An electricity supply path 71 which is embedded into the support portion 40 or drawn into the inside of the support portion 40 from a back surface supplies electricity to the shaft portion 34 via an electricity supply brush (not shown in the drawing) from the external power source 70. The shaft portion 34 is made of a conductive raw material such as a titanium material, a phosphor bronze material, a pure copper material or the like, and supplies electricity to the fixing bolt 35 which is also made of a conductive raw material. Then, electricity is supplied to the first electricity supply members 314 via an electricity supply paths (not shown in the drawing) which is embedded in the inside of the holding member 31 from the fixing bolts 35, 36 provided for fixing the holding member 31.
Next, the rotary means for the substrate holder 30 is explained. As the rotary means for the substrate holder 30 in the plating jig 2 of the present invention, a method which makes use of the flow of plating solution by providing blade portions or recessed portions on an outer peripheral surface of the outer frame member or a method which rotates the substrate holder 30 by a drive part can be adopted.
The rotary means for the substrate holder 30 is not limited to either one of the above-mentioned methods, that is, the method which makes use of the flow of plating solution by forming the blade portions or the recessed portions on the outer peripheral surface of the outer frame member 33, and the method which rotates the substrate holder 30 by the drive part, and the rotary means may be combination of these rotary means. That is, a rotational force may be imparted to the substrate holder 30 by forming the blade portions or the recessed portions on the outer peripheral surface of the outer frame member 33 and, at the same time, a rotational force may be imparted to the substrate holder 30 by using an external drive part. In this manner, with the use of two kinds of different rotational forces, the rotation of the substrate holder 30 can be made further stable thus suppressing the power consumption.
Next, a plating device which uses the plating jig 2 of the present invention is explained.
A jetting port 12 to which the piping 80 is connected is formed in the bottom portion of the plating bath 10, and a plating solution is supplied into the inside of the plating bath 10 through the jetting port 12. When the jig which makes use of the flow of the plating solution by forming the blade portions or the recessed portions on the outer peripheral surface of the outer frame members shown in
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2012/060655 | 4/20/2012 | WO | 00 | 10/16/2014 |
