JP7329268B2 - Jet plating equipment - Google Patents

Description

The present invention relates to a jet plating apparatus capable of shortening the plating time for metal plating such as copper plating formed on the surface of a semiconductor wafer and uniformizing the film thickness of the plating film.

Conventionally, an electroplating apparatus forms a plating film made of a metal film such as copper on the surface of a semiconductor wafer (the surface on which semiconductor chips are mounted and wiring is formed) in order to increase conductivity. is used.

This electroplating apparatus is basically composed of a plating tank in which a certain amount of a plating solution containing metal ions is stored, an anode part that is connected to a metal plate immersed in the plating solution and energized, and a metal plate immersed in the plating solution. and a cathode portion that is connected to a semiconductor wafer and is energized.

As a result, by applying positive and negative voltages, an anodic reaction (oxidation reaction) and a cathodic reaction (reduction reaction) occur in the metal plate in the tank and the semiconductor wafer, respectively, ionizing the metal plate and eluting it into the plating solution. A plating film is formed by depositing ionized metal on the mounting surface of the semiconductor wafer.

As such an electroplating apparatus, a jet-type plating tank configured to actively inject the plating solution in the tank toward the semiconductor wafer, and a starting end communicating with the jet-type plating tank and a terminal end are provided. Various types of jet plating apparatuses have been proposed that include a circulation pipe that faces a plating tank and a pump that is interposed in the middle of the circulation pipe (see, for example, Patent Documents 1 and 2).

Such a jet-type plating tank has a plating solution ejection nozzle provided at the end of the circulation pipe, the ejection nozzle forms a plurality of openings for ejecting new plating solution toward the semiconductor wafer, and the pooled plating solution is configured to control the flow so that it is evenly applied to the semiconductor wafer.

As a result, it is possible to accelerate the deposition of the plating film on the semiconductor wafer by the anodic reaction and the cathodic reaction with less power consumption, thereby shortening the plating time and improving the in-plane uniformity of the plating film.

JP-A-2005-97732 JP 2006-117966 A

However, the above-described conventional jet-type plating tanks all have problems in that the nozzle structure is complicated, which is disadvantageous in terms of cost, and that the overall size of the apparatus increases, requiring an extra installation space.

That is, the injection nozzle according to Patent Document 1 is an annular nozzle in which a plurality of openings are formed at regular intervals on the annular surface. There are space problems and fluid control problems such as an increase in the size of the entire apparatus because a plating bath must be formed, and an arrangement configuration in which each spray opening is adjusted to face the wafer.

In addition, the injection nozzle according to Patent Document 2 is a linear nozzle having a single elongated opening or a plurality of openings formed at regular intervals on one side surface of a cylinder, and is movable parallel to the semiconductor wafer in the plating tank. Since it is constructed so as to be able to adjust the flow of the fluid, there is a problem that the size of the apparatus increases as much as the movement apparatus is attached, as described above.

In particular, since any nozzle structure has a plurality of openings and elongated openings, depending on the distance from the terminal end of the circulation pipe, the opening on the base end of the nozzle located near the pipe and the opening on the far side of the pipe. There is a problem that the discharge flow rate of the plating solution varies due to the influence of the pressure drop that occurs between the openings on the end side of the nozzles.

That is, the flow pressure of the plating solution at the base end of the nozzle near the circulation pipe is stable because it is in the vicinity of the circulation pipe, and the flow rate of the plating solution discharged from the base end side opening of the nozzle becomes constant. On the other hand, the flow pressure of the plating solution at the terminal end of the nozzle located far from the circulation pipe drops by that amount because the plating solution is discharged from the openings in between, and therefore the plating solution flows from the end side opening. The discharge flow rate will be less than the discharge flow rate from the proximal side opening.

In other words, the flow rate of the plating solution varies depending on the distance from the circulation pipe of each opening, causing a drift in the pooled plating solution, which causes a difference in the flow rate per unit time of the plating solution contacting the surface of the semiconductor wafer. As a result, the formed film thickness may be uneven.

In order to eliminate the flow rate difference of the plating solution from each opening, it is conceivable to enlarge or reduce the opening diameter or the inner diameter of the nozzle according to the distance from the circulation pipe. The design must also consider pressure, and the structure becomes unnecessarily complicated.

On the other hand, in the case of a general curved nozzle formed with a single opening, there is a possibility that the jet flow may become non-uniform due to the uneven flow occurring inside the nozzle. 9(a) and 9(b) show a conventional curved ejection nozzle 100 and its schematic flow velocity distribution. The shading in FIG. 9(a) indicates that the flow velocity distribution of the plating solution is such that a dark-colored area indicates a high flow velocity area and a light-colored area indicates a slow flow velocity area.

In general, in a curved flow passing through a curved portion 101 in a single flow path system, the inner peripheral side of the curved flow becomes a low pressure area to increase the flow velocity, and the outer peripheral side of the curved flow becomes a high pressure area to decrease the flow velocity. For this reason, when the curving flow reaches the downstream side of the curved flow, drifting occurs under the influence of the flow velocity difference between the inner and outer circumferences of the curving flow, and the flow velocity distribution becomes uneven.

As a result, a non-uniform flow with a difference in flow velocity between the top and bottom is discharged as it is from the end opening 102 of the nozzle 100, causing turbulence or the like in the stored nozzle liquid, and the plating liquid is spread evenly over the wafer surface W1 of the semiconductor wafer W. The plated film cannot be applied, resulting in unevenness in the film thickness of the plated film.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances. Jet-type plating can promote film thickness growth by dispersing and uniforming the plating, can be installed at low cost and space-saving, and can form a plating film that maintains in-plane uniformity on a semiconductor wafer in a short time. A vat nozzle structure is provided.

In order to solve the above problems, the nozzle structure of the jet plating tank according to the present invention includes: (1) A semiconductor wafer is disposed near one side wall of the jet plating tank, and a plating solution ejection nozzle faces the semiconductor wafer. in the jet-type plating bath of the jet-type plating apparatus for plating the surface of the semiconductor wafer, forming a plurality of jet paths at the opening of the plating solution ejection nozzle, and jetting from the end opening of each jet path Dispersion and homogenization of the plating solution in the plating tank are performed by the plating solution applied.

Further, the nozzle structure of the jet-type plating bath according to the present invention is characterized by the following points (2) to (4).
(2) The plurality of jet paths formed in the opening of the plating solution ejection nozzle are formed by a plurality of partition walls arranged inside the opening of the nozzle.
(3) The plurality of jet paths formed in the opening of the plating solution ejection nozzle are formed by a perforated plate arranged in the opening of the nozzle.
(4) The jet-type plating bath includes a donut-shaped plate interposed between the semiconductor wafer and the plating solution ejection nozzle disposed on one side wall, and the donut-shaped plate has a circular ring opening in the center. The annular surface faces the semiconductor wafer with a certain gap therebetween, and the center of the ring opening is positioned coaxially with the center of the opening of the plating solution ejection nozzle and the center of the semiconductor wafer. what i did.

According to the present invention, there is provided a jet plating apparatus in which a semiconductor wafer is arranged in the vicinity of one side wall of a jet plating tank, and a plating solution ejection nozzle is provided facing the semiconductor wafer to perform plating on the surface of the semiconductor wafer. In the jet-type plating tank, a plurality of jet paths are formed at the opening of the plating solution ejection nozzle, and the plating solution jetted from the end opening of each jet path disperses and homogenizes the plating solution in the plating tank. Therefore, the plating solution flowing out from the upstream side to the downstream side of the single flow path can be divided and discharged by a plurality of jet flow paths formed in the opening of the nozzle. The flow velocity of the plating solution is rectified to be constant, and the flow of the plating solution in the plating bath is regulated in a fixed direction, thereby suppressing the occurrence of uneven flow.

That is, the plating solution can be jetted at substantially the same flow rate from the terminal opening of each jet path, and the contact flow rate of the plating solution to the semiconductor wafer surface facing the nozzle per unit time is increased, resulting in film thickness growth. In addition, the plating solution can be sprayed as uniformly as possible on the surface of the semiconductor wafer to form a plating film with in-plane uniformity in a short period of time.

In particular, when the ejection nozzle is in a curved form, the curved flow occurs between the outer peripheral side of the curved flow and the inner peripheral side of the curved flow when the plating solution that has flowed out from the base end inside the nozzle opening is bent at the curved portion. It is possible to eliminate the flow velocity difference and generate a rectifying action that substantially uniforms the flow velocity.

That is, in the present invention, by forming a plurality of jet paths at the end opening, the occurrence of uneven flow resulting in non-uniform flow velocity distribution is suppressed. It is rectified so as to jet out the plating solution at a flow rate.

As a result, a plating solution jet can be generated at a constant flow velocity while the flow direction of the plating solution in the plating tank is set to be the opposite direction orthogonal to the surface direction of the semiconductor wafer surface.

The jet impinging on the surface of the semiconductor wafer spreads radially around the impinging portion and transforms into a wall surface flow that traces the wafer surface. As a result, it is possible to evenly contact the plating solution over the entire surface of the wafer, thereby promoting film thickness growth and forming a plated film without irregularities.

Further, according to another aspect of the present invention, the plurality of jet paths formed in the opening of the plating solution ejection nozzle are formed by a plurality of partition walls disposed inside the opening of the nozzle. By dividing the flow of the plating solution by , there is an effect that the plating solution can be radially diffused substantially uniformly from the opening of the plating solution ejection nozzle and sent to the semiconductor wafer.

That is, the difference in flow velocity caused by the curving flow of the plating solution due to the influence of the low-pressure area on the inner circumference side and the high-pressure area on the outer circumference side formed by the bent portion of the nozzle is eliminated by narrowing the upper and lower intervals of each jet path, thereby making the flow velocity substantially uniform. rectifying action can be further improved.

Further, according to another aspect of the present invention, the plurality of jet paths formed in the opening of the plating solution ejection nozzle are formed by a perforated plate disposed in the opening of the nozzle, so that the structure is further simplified. However, in the same way as described above, namely, the rectifying action that eliminates the flow velocity difference that causes the curving flow of the plating solution due to the influence of the inner and outer low pressure areas and the high pressure areas formed by the bent portion of the nozzle, and makes the flow velocity substantially uniform. has the effect of further improving the

Further, according to another aspect of the present invention, the jet-type plating bath includes a donut-shaped plate interposed between the semiconductor wafer and the plating solution ejection nozzle disposed on one side wall, and the donut-shaped plate has a circular ring opening in the center, the annular surface faces the semiconductor wafer with a certain gap, and the center of the ring opening is aligned with the center of the opening of the plating solution ejection nozzle and the center of the semiconductor wafer. Since the wall surface flow of the plating solution from the center of the semiconductor wafer to the outer peripheral side flows in a certain gap, it is possible to suppress the wall flow from attenuating on the outer peripheral side and becoming a turbulent flow. It is possible to evenly bring the plating solution into contact with the entire surface of the semiconductor wafer, thereby promoting the formation of a plated film without irregularities.

1 is an overall perspective view of a jet plating apparatus having a nozzle structure of the present invention; FIG. 1 is a schematic side view of a jet plating apparatus having a nozzle structure of the present invention; FIG. 1A and 1B are a perspective view and a side cross-sectional view showing the configuration of a nozzle structure according to Example 1. FIG. 1A and 1B are a perspective view and a schematic side view showing the configuration of a wafer holder according to Example 1; FIG. FIG. 2 is a schematic flow velocity distribution diagram of a jet due to the nozzle structure according to Example 1; FIG. 8 is a perspective view and a side cross-sectional view showing the configuration of a nozzle structure according to Example 2; FIG. 10 is a front view showing the structure of a perforated plate according to Example 2; FIG. 10 is a schematic flow velocity distribution diagram of a jet due to the nozzle structure according to Example 2; It is an external view and a schematic flow velocity distribution diagram showing the configuration of a conventional ejection nozzle.

The gist of the present invention is a jet plating apparatus in which a semiconductor wafer is arranged in the vicinity of one side wall of a jet plating tank, and a plating solution ejection nozzle is provided facing the semiconductor wafer to perform plating on the surface of the semiconductor wafer. In the jet-type plating tank, a plurality of jet paths are formed at the opening of the plating solution ejection nozzle, and the plating solution jetted from the end opening of each jet path disperses and homogenizes the plating solution in the plating tank. To provide a nozzle structure for a jet-type plating tank characterized by performing

Also, the plurality of jet paths formed in the opening of the plating solution ejection nozzle is characterized by being formed by a plurality of partition walls arranged inside the opening of the nozzle.

Also, the plurality of jet paths formed in the opening of the plating solution ejection nozzle is characterized by being formed by a perforated plate disposed in the opening of the nozzle.

Further, the jet-type plating bath is provided with a donut-shaped plate interposed between the semiconductor wafer and the plating solution ejection nozzle arranged on one side wall, and the donut-shaped plate has a circular ring opening in the center. The annular surface faces the semiconductor wafer with a certain gap therebetween, and the center of the ring opening is positioned coaxially with the center of the opening of the plating solution ejection nozzle and the center of the semiconductor wafer. It is characterized by

In recent years, semiconductor wafers have been plated not only on the mounting surface but also on the back surface in order to improve electrical conductivity, reduce resistance, and reduce power consumption. In particular, copper plating, which is advantageous in terms of cost and conductivity, has become mainstream.

Semiconductor wafers with copper plating on both sides are used in electronic devices such as smartphones and notebook computers. reduction.

The film thickness of the plating film can be made thicker (for example, 3 μm or more) than the film thickness (for example, 1 to 3 μm) of the plating film formed by a general plating method such as a sputtering method or a vapor deposition method. requested.

In other words, the sputtering method and vapor deposition method are not suitable for forming a thick plated film, and the electroplating method, that is, the electroplating apparatus is usually used. Among them, the jet plating apparatus is effective in that it can form a film in a short time while saving energy without increasing the concentration of metal ions in the plating solution.

That is, the nozzle structure of the jet-type plating tank of the present invention is simple, but greatly increases the chances of metal ions in the plating solution coming into contact with the surface of the semiconductor wafer, thereby forming a thick plating film on the surface of the wafer. It can be said that it is an epoch-making invention that can be formed in a short time without any problems and can be retrofitted to existing jet-type plating equipment to change the specifications to a high-speed electroplating equipment.

[Example 1]
An embodiment of the nozzle structure of the jet plating tank according to the present invention will be described below. 1 and 2 are an overall perspective view and a schematic side view of a jet plating apparatus having a nozzle structure, FIG. 3 is a perspective view and a side sectional view showing the configuration of the nozzle structure of Example 1, and FIG. 4 is an example. 1 is a perspective view and a schematic side view showing the configuration of the wafer holder of Example 1, and FIG.

1 and 2, the jet plating apparatus B comprises a jet plating tank 1 having a plating solution ejection nozzle 2 having a nozzle structure A according to the present invention, and the plating tank 1 A circulation pipe B1 connected at both ends to the bottom of the tank, a supply pump B2 provided in the middle of the circulation pipe B1, a metal plate M supported downwardly in the plating tank 1 while facing each other and separated from each other, and It comprises a semiconductor wafer W, and a power supply section B3 for applying positive and negative voltages to the metal plate M and the semiconductor wafer W, respectively.

In the circulation pipe B1, in FIG. 2, reference numeral B6 is a flow meter provided downstream of the supply pump B2 to measure the flow rate of the plating solution, and reference numeral B7 is provided downstream of the flow meter B6. A heater B8 is provided on the downstream side of the heater B7 to maintain the plating solution at 40 to 50° C. to promote the anode-cathode reaction. It is a filter for filtering the plating solution by trapping particles such as dust that are liberated in the plating solution.

That is, the flow meter B6, the heater B7, and the filter B8 are sequentially interposed from the upstream side to the downstream side between the supply pump B2 and the nozzle 2 in the circulation pipe B1. The filter B8 is composed of a joint with a detachable filter or a pipe.

As shown in FIGS. 1 and 2, the jet plating bath 1 is a rectangular box-shaped container with an upper opening capable of storing a certain amount of plating solution, and the internal space is formed substantially at the center of the bottom side wall in the longitudinal direction. A plating tank section 11 for plating a semiconductor wafer and a reserve tank section 12 for temporarily storing the plating solution overflowing the overflow wall 10 from the plating tank section 11 are formed by an overflow wall 10 that is erected. It is divided into .

A plating tank portion 11 and a reserve tank portion 12 are accommodated in the jet-type plating tank 1 with an overflow wall 10 interposed therebetween, and the inside of the jet-type plating tank 1 is divided into front and rear halves by the overflow wall 10. forming.

In the plating bath portion 11, a semiconductor wafer W and a metal plate M are suspended by a wafer holder B5 and a metal plate holder B4 so as to face each other in the plating solution stored in the plating bath portion 11. The maximum storage amount of the plating solution in the tank portion 11 is set to the minimum amount necessary for processing (at least the amount that the entire semiconductor wafer W can be immersed), and the volume is reduced to make it as compact as possible.

The wafer holder B5 and the metal plate holder B4 are made of conductive material, respectively. is used as an anode and the semiconductor wafer W is used as a cathode.

Specifically, the semiconductor wafer W is suspended from the wafer holder B5 and arranged face-to-face near one side wall of the plating tank section 11, while the metal plate M is suspended from the metal plate holder B4 and placed over the metal plate holder B4. They are arranged face-to-face in the vicinity of the flow wall 10 .

As shown in FIG. 4, the wafer holder B5 includes a rectangular metal plate suspended portion B50 connected to the power supply portion B3, a short cylindrical ring-shaped holder body B51 connected to the lower end of the suspended portion B50, and a holder body B51. It is composed of a doughnut-shaped plate B52 connected to the suspended portion B50 with a certain gap in the front.

That is, the jet-type plating tank 1 includes a semiconductor wafer W housed in the plating tank section 11, a donut-shaped plate B52 disposed opposite to it, and a substantially L-shaped plating plate disposed behind the donut-shaped plate B52. and a liquid ejection nozzle 2 .

A recess for engaging the outer edge of the wafer is formed in the inner peripheral surface of the holder body B51 of the wafer holder B5, and the wafer is fitted and fixed in this recess.

The donut-shaped plate B52 has an annular shape with a donut-shaped opening B520 in the center, and forms a constant gap S between the annular surface B521 and the wafer surface W1 for jetting the plating solution. The positional relationship between the liquid ejection nozzle 2, the donut-shaped plate B52, and the semiconductor wafer W is as follows: the opening center C of the opening 2a of the plating solution ejection nozzle 2; the opening center B51C of the donut-shaped plate B52; WC are positioned on the same axis.

A constant gap S is formed between the semiconductor wafer W and the donut-shaped plate B52. By integrally fitting the pin B530 of the B523 with the hole B53 provided in the inverted L-shaped donut-shaped plate support portion B524 projecting from the hanging portion B50, the semiconductor wafer W and the donut-shaped plate B52 are kept at a constant gap. They are arranged facing each other while holding S. The constant gap S is set to a gap of about 1.0 mm to 10.0 mm through which the wall flow of the plating solution flowing along the semiconductor wafer surface W1 can pass.

The ring width d of the doughnut-shaped plate B52 is formed to be about 1/5 to 1/2 of the radius r of the semiconductor wafer W. As shown in FIG.

Reference numeral B531 in FIG. 4A denotes a pin protruding from the lower end of the annular ring of the holder body B51 for the semiconductor wafer W, and the donut-shaped plate B52 faces the semiconductor wafer W of the holder body B51 with a predetermined gap S therebetween. A pin B531 is inserted into an insertion hole B522a of a protruding lower end flange B522 of the donut-shaped plate B52 to enable the position of the donut-shaped plate B52 to be fixed.

Since the ring opening B520 as a donut hole is formed in the center of the donut-shaped plate B52 in this manner, the plating solution jet flow discharged from the nozzle opening 2a is injected inward into the ring opening B520 and then into the rearward direction. A flow path is formed to flow into the fixed gap S between the semiconductor wafer W thus formed.

The jet flow of the plating solution is caused by the donut-shaped plate B52 and the space between the donut-shaped plate B52 vertically installed along the semiconductor wafer surface W1, that is, the space between the donut-shaped circumferential ring surface of the semiconductor wafer W and the donut-shaped plate B52. It disperses in the doughnut-shaped constant gap S formed between the annular surface B521.

As a result, it is possible to prevent the wall surface flow, which will be described later, from becoming turbulent by attenuating the flow velocity as it goes from the center of the semiconductor wafer W toward the outer periphery, and it is possible to evenly bring the plating solution into contact with the entire surface of the semiconductor wafer W. there is

The dimensions of the plating bath section 11 for the semiconductor wafer W suspended by the wafer holder B5 are such that the semiconductor wafer W can be completely immersed in the plating solution.

That is, the dimension of the overflow wall 10 that determines the maximum storage amount of the plating solution in the plating bath section 11 is designed according to the diameter of the semiconductor wafer W that is immersed and supported in the plating solution with its plate surface facing in the horizontal direction. , the height h and width d of the overflow wall 10 are made longer than the diameter φ of the semiconductor wafer W. As shown in FIG.

Specifically, the relationship between the height h (mm) and width d (mm) of the overflow wall 10 and the diameter φ (mm) of the semiconductor wafer W is h (mm)−φ (mm)=10 to 150 (mm) and d (mm) - φ (mm) = 50 to 150 (mm).

The overflow wall 10 of this embodiment is a partition plate having a square shape when viewed from the front, and has approximately the same height h and width d. .

In the plating bath section 11, the semiconductor wafers W are arranged near the front wall, and the metal plates M are arranged near the overflow wall 10, symmetrically with respect to the central portion of the longitudinal length as viewed from the side. The distance between the semiconductor wafer W and the metal plate M is, for example, 150-170 mm.

The reserve tank section 12 is a rectangular box-shaped portion with an upper opening adjacent to the plating tank section 11 via the overflow wall 10 and temporarily stores the plating solution overflowing from the plating tank section 11 . The reserve tank part 12 of this embodiment is configured to be able to store, for example, approximately 7 to 9 L of plating solution.

The plating tank section 11 and the reserve tank section 12 may be arranged vertically. In this case, the plating bath portion 11 and the reserve bath portion 12 have a starting end opening facing an upper portion of one side of the plating bath portion 11 located above, and a terminal opening facing one side of the reserve bath portion 12 located below. They may be communicated with each other by an overflow pipe.

In the jet-type plating bath 1 compacted in this way, the plating bath portion 11 and the reserve bath portion 12 are configured to communicate with each other through a substantially U-shaped circulation pipe B1 at their bottoms. .

As shown in FIGS. 1 and 2, the circulation pipe B1 has a starting end that communicates with the center of the bottom of the reserve tank section 12, and a terminal end that passes through the center of the bottom of the plating tank section 11. Inside, the end opening faces upward and protrudes upward. A supply pump B2 interposed in the middle of the circulation pipe B1 sends about 8 to 15 L of plating solution per minute toward the terminal opening.

At the end B10 of the protruding circulation pipe B1, a jet nozzle 2 bent in a substantially L shape is attached so as to finally jet the plating solution into the jet-type plating bath 1 (plating bath portion 11). .

As shown in FIG. 3A, the ejection nozzle 2 is a cylindrical inverted L-shaped pipe bent at right angles when viewed from the side, and includes a vertical portion 20 on the base end side extending in the vertical direction and a vertical portion 20 and a horizontal portion 22 on the distal end side extending horizontally through a bent portion 21 at the upper end of the .

As shown in FIG. 2, the end opening of the horizontal portion 22 is a nozzle opening 2a, and the opening center (axis center of the horizontal portion 22) of the opening 2a is aligned with the surface center WC of the semiconductor wafer surface W1 and the opening surface is opposed to the surface of the semiconductor wafer W, and communicated with the end portion B10 of the circulation pipe B1 via the vertical portion 20. As shown in FIG.

As shown in FIGS. 3(a) and 3(b), the ejection nozzle 2 has joint surfaces 20a and 22a formed by cutting a vertical portion 20 and a horizontal portion 22 at an angle of 45° with respect to the cylinder axis. A bent portion 21 bent at 90° is formed by overlapping the joint surfaces.

In other words, the plating solution jetting nozzle 2 has the maximum inner diameter at the bent portion 21, the same inner diameter at the vertical portion 20 and the horizontal portion 22, and the inner spaces of each forming a continuous single flow path. This suppresses, as much as possible, the occurrence of drift accompanying the curving flow of the plating solution at the bent portion 21 . The inner diameters of the vertical portion 20 and the horizontal portion 22 of this embodiment are approximately 25 to 27 mm.

Further, as shown in FIG. 2, the vertical portion 20 is connected at its proximal end to the terminal portion B10 of the circulation pipe B1 so as to horizontally support the upper horizontal portion 22 at a constant height.

As shown in FIG. 2, the height of the vertical portion 20 is such that the central axis of the upper horizontal portion 22, that is, the opening center C of the nozzle opening 2a of the jet nozzle 2 is the jet plating bath 1 (plating bath portion 11). The height is maintained at a level that is on the same line as the plane center WC of the semiconductor wafer surface W1 that hangs down inside.

In order to allow such setting, the jet nozzle 2 can be configured so that the vertical portion 20 slides up and down on the end portion B10 of the circulation pipe B1 so that the height position of the nozzle can be adjusted.

Further, the horizontal projection length of the horizontal portion 22 from the vertical portion 20 is determined by the relative distance between the nozzle opening 2a at the tip and the semiconductor wafer W facing thereto.

That is, the distance between the opening surface of the nozzle opening 2a and the opposing semiconductor wafer surface W1 is set to 3 to 50 mm. This is preferable in terms of forming a wall flow that diffuses radially around the wafer surface W1.

As shown in FIGS. 3(a) and 3(b), the ejection nozzle 2 forms a plurality of jet paths 3 in the opening 2a, and the plating solution jetted from the end opening 3a of each jet path 3. A nozzle structure A that disperses and homogenizes the plating solution in the plating tank 1 is constructed by the following.

As shown in FIGS. 3(a) and 3(b), the cylindrical ejection nozzle 2 having an inverted L-shaped outer shape has a plurality of partition walls in the same inverted L-shape as the outer shape of the ejection nozzle 2 in the outer cylinder. 4 and 4' are laminated with a constant space therebetween.

The interior of the ejection nozzle 2 forms a plurality of layers of ejection passages due to the mutual gaps between the plurality of partition walls 4 and 4' and the gaps between the inner wall of the outer cylindrical body and the partition walls.

Therefore, the horizontal wall portions 42, 42' end faces of the plurality of partition walls 4, 4' appear at the opening end face of the ejection nozzle 2, and the vertical wall portions are formed at the rear ends of the horizontal wall portions 42, 42'. 40 and 40' are formed to form a plurality of layers of inverted L-shaped jet passages inside the inverted L-shaped ejection nozzle 2 in this manner.

As shown in FIG. 3B, each of the partition walls 4 and 4' is an inverted L-shaped bent plate similar in shape to the inverted L shape of the ejection nozzle 2 when viewed from the side. In a side sectional view, it is composed of an inner partition plate 4 arranged on the inside of the inverted L-shaped bend and an outer partition plate 4' arranged on the outer side of the inverted L-shaped bend.

As shown in FIG. 3(b), the inner and outer partition walls 4 and 4' are respectively composed of vertical wall portions 40 and 40' arranged vertically corresponding to the vertical portion 20 in the ejection nozzle 2, and a bent portion 21. and horizontal wall portions 42 and 42' horizontally arranged corresponding to the horizontal portion 22, and the horizontal portion 22 In the vertical portion 20, the horizontal wall portions 42, 42' are arranged in the vertical direction, and in the vertical portion 20, the vertical wall portions 40, 40' are arranged in the longitudinal direction at regular intervals in parallel.

Specifically, inside the nozzle opening 2S, the inner and outer partition walls 4, 4' are arranged parallel to the vertical wall portions 40, 40' vertically in the horizontal portion 22 at regular intervals. are arranged parallel to the plane at equal intervals in the front-rear direction, and a virtual diagonal line formed by the bent inner corner and the bent outer corner of the bent portion 21 (in FIG. 3B, the vertical portion 20 indicated by the dashed line and By aligning the corners of the curved wall portions 41 and 41 with the overlapping portions of the joint surfaces 20a and 22a with the horizontal portion 22, the nozzle opening inside 2S of the ejection nozzle 2 is bent at a right angle. A single flow path is divided into a plurality of jet flow paths 3 to form partitions.

As shown in FIG. 3(b), each of the jet flow paths 3 includes upper and lower jet flow paths 3, 3'' formed in upper and lower portions of the inside 2S of the nozzle opening in a radial cross-sectional view of the inside 2S of the nozzle opening. A central jet passage 3′ having rounded corners and having arcuate ends is formed in the central portion between the upper and lower jet passages 3 and 3″.

In addition, each of the jet flow paths 3 to 3'' is formed by the inner and outer partition walls 4 and 4' as a flow path similar in shape to the inverted L shape of the ejection nozzle 2 in a side sectional view of the inside 2S of the nozzle opening. be.

Specifically, as shown in FIG. 3B, each of the jet flow paths 3 to 3'' has vertical flow paths 30 to 30 extending in the vertical direction corresponding to the vertical portion 20 inside the nozzle opening 2S. '', curved flow paths 31 to 31'' that bend and extend in the right angle direction corresponding to the curved portion 21, and horizontal flow paths 32 to 32'' that extend in the horizontal direction corresponding to the horizontal portion 22. have.

As shown in FIG. 3B, the tip edges of the inverted L-shaped partition walls 4 and 4' are flush with the opening end face of the ejection nozzle 2, and the ends of the inverted L-shaped partition walls 4 and 4' The edge reaches halfway up the vertical portion 20 of the liquid ejection nozzle 2 .

The vertical width of each jet path 3-3'' is about 1/4-1/3 of the inner diameter of the vertical portion 20 and the horizontal portion 22. As shown in FIG. The number and vertical width of each of the jet paths 3 to 3'', that is, the number of partition walls 4 and their mutual intervals are not particularly limited as long as the drift of the plating solution inside the nozzle opening 2S is suppressed. do not have.

For example, in the ejection nozzle 2, a plurality of partition walls 4, 4' form a plurality of jet paths so that the vertical length is gradually reduced from the outer side to the inner side of the L shape. It is also possible to attenuate the flow velocity in the highest velocity region at .

Due to such jet paths 3 to 3'', as shown in FIG. The flow speed and flow rate of the plating solution are made constant at the horizontal portion 22 by eliminating the flow speed difference between the inner and outer peripheral sides of the flow. 5. As in FIG. 9, the shading in FIG. 5 indicates that the flow velocity distribution of the plating solution is such that a dark-colored area indicates a high-velocity area and a light-colored area indicates a low-velocity area.

Specifically, as shown in FIG. 5, the plating solution flowing out from the vertical portion 20 on the base end side is divided into equal parts of the pressure supplied from the pump before forming a curved flow at the bent portion 21, and each jet flows. Divert entry into channel 3-3''.

The plating solution that has branched into each of the jet paths 3 to 3'' reaches the bent portion 21 that causes drift, but as shown in FIGS. Since the vertical width (the distance between the curved corners) of the curved flow paths 3 1 to 31 ″ of 3″ is narrower than the vertical width of the curved portion 21 in the single flow path, There is no difference in flow velocity between the inner and outer peripheral sides, and drift is less likely to occur.

That is, the jet paths 3 to 3'' regulate the pressure without generating a pressure loss difference between the inner and outer circumferences of the curved flow, and maintain the pump pressure as much as possible to the jet paths 3 to 3''. , and the plating solution is caused to flow out to the horizontal channels 32 to 32'' of each channel.

As shown in FIGS. 3B and 5, the plating solution flowing out of the horizontal flow paths 32 to 32'' of the jet flow paths 3 to 3'' is finally formed flush with the nozzle opening 2a. From each of the end openings 3a to 3a'', the liquid jets are jetted uniformly with a constant flow velocity and flow rate. 2, the thick arrow indicates the flow of the plating solution stored in the plating bath section 11. As shown in FIG.

As shown in FIG. 2, the plating solution jet discharged from the nozzle opening 2a into the plating solution stored in the plating bath portion 11 causes a constant dispersed induced flow in the pooled plating solution.

That is, the nozzle liquid containing a large amount of metal ions eluted from the metal plate M located behind the nozzle is sent forward toward the front surface W1 of the semiconductor wafer while being caught in the jet flow of the plating liquid.

At this time, the plating solution jet of the plating solution main stream is directed toward the center of the plane WC of the semiconductor wafer front surface W1 facing the nozzle opening 2a. When the plating solution jet hits the surface center WC of the semiconductor wafer surface W1, it diffuses radially from the hit portion to form a wall flow along the semiconductor wafer surface W1.

As shown in FIG. 2, the wall flow flows from the center of the semiconductor wafer surface W1 to the outer periphery so as to trace the entire surface of the semiconductor wafer surface W1, and collides with the flooded surface and the bottom side wall and the left and right side walls of the plating bath section 11 and flows backward. It turns back to the side, becomes a return wall flow along each surface, and flows to the rear position where the metal plate M is located.

Especially in this embodiment, as shown in FIG. 4(b), since the wafer holder B5 is provided with the doughnut-shaped plate B52, the wall flow on the semiconductor wafer front surface W1 gradually increases from the center toward the outer peripheral edge. Even if the wall flow is attenuated to 100%, the flow direction can be rectified by guiding the flow direction from the outside by the donut-shaped plate B52 while suppressing the wall flow that is attenuated on the outer peripheral end side from changing to turbulent flow. can.

Therefore, it is possible to prevent the plating solution from stagnating due to unintentional turbulence generated on the outer peripheral side of the semiconductor wafer front surface W1, thereby preventing the film thickness of the plating film from becoming uneven.

In this way, as shown in FIG. 2, in the plating solution stored in the plating bath portion 11, the nozzle position is the center, and the jet flow paths 3 to 3'' move toward the front side at the center of the front view. A central flow region for flowing, a wall flow region for diffusing and radiating vertically and horizontally along the wafer surface W1 on the front side, and a return wall surface for flowing backward along the water-filled surface and the bottom side wall and the left and right side walls of the plating tank section 11. A circulating flow formed by the flow area is generated in an orderly fashion.

As a result, the plating solution containing a large amount of metal ions eluted from the metal plate M is jetted in an orderly fashion from the nozzle openings 2a onto the semiconductor wafer W while the concentration of metal ions in the plating solution is uniformized. It can be preferentially induced and sent.

[Example 2]
Next, a nozzle structure A2 according to Example 2 will be described. 6(a) and 6(b) are a perspective view and a side sectional view showing the configuration of the nozzle structure of this embodiment, FIG. 7 is a front view showing the configuration of the perforated plate of this embodiment, and FIG. FIG. 10 is a schematic flow velocity distribution diagram of a jet due to the nozzle structure of the example; In addition, in the following description, the same code|symbol is used for what has the same structure as Example 1, and description is abbreviate|omitted.

The nozzle structure A2 according to this embodiment is constructed by forming a plurality of jet paths 50 to 54 with a perforated plate 5 in which the opening 2a of the nozzle 2 is provided.

The perforated plate 5 is disc-shaped and has a plurality of jet holes 50 to 54 penetrating through the plate surface. The perforated plate 5 may have its plate surface abutted and fixed to the opening end surface of the opening 2a of the ejection nozzle 2, or its outer peripheral surface abutted and fixed to the inner edge of the opening 2a of the ejection nozzle 2. can be anything.

The perforated plate 5 is provided with a plurality of jet holes 50 to 54 so as to open the opening 2a of the ejection nozzle 2 at an opening ratio of about 65 to 75% when installed in the opening 2a of the ejection nozzle 2. there is

The plurality of jet holes 50 to 54 are arranged radially and concentrically (in the shape of annual rings) from the center of the plate surface of the perforated plate 5 to the outer peripheral side in a front view (viewed in the axial direction of the jet nozzle 2), and maintain a predetermined pitch. A disk plate is formed so as to penetrate in the plate thickness direction.

Specifically, the plurality of jet holes are formed by concentrically arranging holes having different hole diameters. 5 inner large holes 51 penetratingly formed, 10 outer large holes 52 penetratingly formed along the outer circumference of the inner large hole 51, and between the inner large hole 51 and the outer large hole 52 A total of 31 holes, including five small inner holes 53 penetrating through the gaps between the two and ten small outer holes 54 penetrating through the gaps between the adjacent outer large holes 52, 52. It consists of

The hole diameters of the jet holes 50 to 54 are such that the inner large hole 51 = the outer large hole 52 > the central middle hole 50 > the inner small hole 53 > the outer small hole 54, and the aperture ratio of the perforated plate 5 is maximized. Expanding.

As a result, the opening ratio of the nozzle opening 2a is increased as much as possible to eliminate unintentional pressure loss of the plating solution flow in the nozzle and to suppress drifting. From 54a, a rectified jet flow can be generated toward the semiconductor wafer W at a constant flow velocity and flow rate.

Specifically, since the nozzle opening 2a is provided with a perforated plate 5 having an opening ratio narrower than the nozzle diameter, the plating solution ejection nozzle 2 flows out through the vertical portion 20 and the curved portion 21, and the horizontal portion 22 The uneven flow generated in is subjected to damping and pressure regulation action by the perforated plate 5 and is temporarily stored in the horizontal portion 22 .

At the same time, the inside of the plating solution ejection nozzle 2 rises to a constant pressure, and the plating solution that has undergone the attenuated positive pressure action enters the jet holes 50 to 54 and is rectified, and finally to the end openings 50a to 54a. is ejected as a jet from the

That is, the jet holes 50 to 54 as the respective jet paths function as orifices to rectify the uneven flow, enabling generation of the nozzle liquid jet to the semiconductor wafer W at a uniform flow velocity and flow rate.

As another embodiment, the plurality of jet holes of the perforated plate 5 may be changed in their penetrating direction, hole diameter, and number so as to correspond to the uneven flow generated in the plating solution jetting nozzle 2 .

For example, in order to attenuate the flow velocity in the highest velocity region on the outermost peripheral side of the curving flow generated in the horizontal portion 22 via the bent portion 21, the jet holes formed in the upper portion of the perforated plate 5 are inclined in the plate thickness direction to the outer peripheral side. It may be configured such that the perforated plate 5 is inclined toward the center side, a plurality of jet holes are formed so as to gradually reduce the hole diameter from the lower part to the upper part of the perforated plate 5, or the number of the jet holes is reduced.

Furthermore, as another example, the plurality of partition walls 4 and 4' of Example 1 and the perforated plate 5 of this example are combined to form a plurality of jet paths 3 to 3' in the opening 2a of the plating solution jetting nozzle 2. ', 50-54 can also be formed.

As described above, according to the present invention, in spite of its simple structure, the plating solution is jetted substantially uniformly against the surfaces of the facing semiconductor wafers to disperse the plating solution in the plating tank. And uniformity can be achieved to promote film thickness growth, the apparatus can be installed in a space-saving manner at low cost, and a plating film can be formed on a semiconductor wafer in a short period of time while maintaining in-plane uniformity.

That is, the jet plating of a jet plating apparatus in which a semiconductor wafer is arranged in the vicinity of one side wall of a jet plating tank, and a plating solution ejection nozzle is provided facing the semiconductor wafer to perform plating on the surface of the semiconductor wafer. In the tank, a plurality of jet paths are formed at the opening of the plating solution ejection nozzle, and the plating solution jetted from the end opening of each jet path disperses and homogenizes the plating solution in the plating tank. Therefore, the plating solution flowing out from the upstream side to the downstream side of the single flow path can be divided and discharged by a plurality of jet flow paths formed in the opening of the nozzle. is rectified to a constant flow rate, the flow of the plating solution in the plating tank is regulated in a fixed direction, and the occurrence of drift can be suppressed.

In addition, since the plurality of jet passages formed in the opening of the plating solution jetting nozzle are formed by the plurality of partition walls arranged inside the opening of the nozzle, the plating solution is divided into the respective jet passages, whereby the plating There is an effect that the plating solution can be radially diffused substantially uniformly from the opening of the solution ejection nozzle and sent to the semiconductor wafer.

In addition, since the plurality of jet paths formed in the opening of the plating solution ejection nozzle are formed by the perforated plate disposed in the opening of the nozzle, the structure is further simplified. In other words, there is an effect that the rectifying action of substantially uniforming the flow velocity can be further improved by eliminating the difference in flow velocity that causes the curving flow of the plating solution due to the influence of the inner and outer low pressure areas and the high pressure areas formed by the bent portion of the nozzle. .

Further, the jet-type plating bath is provided with a donut-shaped plate interposed between the semiconductor wafer and the plating solution ejection nozzle arranged on one side wall, and the donut-shaped plate has a circular ring opening in the center. The belt surface of the annular belt faces the semiconductor wafer with a certain gap therebetween, and the center of the ring opening is aligned with the center of the opening of the plating solution ejection nozzle and the center of the semiconductor wafer. , the wall surface flow of the plating solution from the center of the semiconductor wafer toward the outer periphery can be prevented from flowing at a constant interval and becoming turbulent due to attenuation of the wall surface flow on the outer periphery. This has the effect of allowing the plating solution to evenly contact the entire surface of the semiconductor wafer, thereby promoting the formation of a plated film without irregularities.

As described above, according to the present invention, it is possible to uniformly contact the plating solution over the entire wafer surface, thereby promoting film thickness growth and forming a plated film without irregularities in a short period of time.

A (A2) Nozzle structure 1 Jet type plating tank 10 Overflow wall 11 Plating tank part 12 Reserve tank part 2 Plating solution ejection nozzle 2a Nozzle opening C Opening center 2S Nozzle opening inside 20 Vertical Part 21 Bent portion 22 Horizontal portion 20a to 22a Joint surface 3 Jet channel (upper jet channel) 3′ Center side jet channel, lower jet channel 3″, 3a to 3a″ Terminal opening 3b ~3b'' start end opening, 30-30'' vertical channel, 31-31'' curved channel, 32-32'' horizontal channel, 4 partition wall (inner partition wall, 4' outer partition plate, 40 ~40' vertical wall part, 41~41' curved wall part, 42~42' horizontal wall part, 5 perforated plate, 50 jet hole (central middle hole), 51 inner large hole, 52 outer large hole, 53 middle small hole Hole 54 Outer small hole 50a to 54a Terminal opening B Jet plating device B1 Circulation pipe B10 Terminal part B2 Supply pump B3 Power supply B4 Metal plate holder B5 Wafer holder B50 Hanging part B51 Holder body, B51C opening center, B52 donut-shaped plate, B520 ring opening, B52C ring opening center, B521 annular surface, B522 lower end flange, B522a insertion hole, B523 flange, B524 donut-shaped plate support portion, B53 perforation, B530 pin, B531 pin, B6 flow meter, B7 heater, B8 filter, W semiconductor wafer, W1 semiconductor wafer surface, WC plane center, M metal plate, S constant gap

Claims (3)

A jet-type plating bath having a plating solution jetting nozzle for jetting a plating solution and storing the plating solution is provided , and the plating is applied toward the semiconductor wafer entirely immersed in the plating solution in the jet-type plating bath . A jet-type plating apparatus for plating the surface of the semiconductor wafer by applying a plating solution jet generated by jetting the plating solution into the plating solution in the jet-type plating tank from a liquid jet nozzle ,
The plating solution ejection nozzle is
It has a cylindrical vertical part extending in the vertical direction, and a cylindrical horizontal part extending horizontally from the upper end of the vertical part and having an opening on the terminal side as a nozzle opening for ejecting the plating solution. and configured in an L shape by the vertical portion and the horizontal portion,
A partition configured as an L-shaped bent plate by a vertical wall portion vertically arranged in the vertical portion corresponding to the vertical portion and a horizontal wall portion horizontally arranged in the horizontal portion corresponding to the horizontal portion. A jet plating apparatus characterized by forming a plurality of jet paths facing the nozzle opening by arranging a plurality of walls parallel to each of the vertical wall portion and the horizontal wall portion. . A jet-type plating bath having a plating solution ejection nozzle for ejecting the plating solution and storing the plating solution is provided, and the plating solution ejection nozzle is directed toward the semiconductor wafer entirely immersed in the plating solution in the jet-type plating bath. A jet-type plating apparatus that applies plating to the surface of the semiconductor wafer by applying a plating solution jet generated by jetting the plating solution into the plating solution in the jet-type plating tank from the jet-type plating tank,
The plating solution ejection nozzle is
It has a cylindrical vertical part extending in the vertical direction, and a cylindrical horizontal part extending horizontally from the upper end of the vertical part and having an opening on the terminal side as a nozzle opening for ejecting the plating solution. and configured in an L shape by the vertical portion and the horizontal portion,
A jet plating apparatus , wherein a perforated plate having a plurality of jet holes is provided at the nozzle opening . 3. The plating solution ejection nozzle according to claim 1 , wherein the center of the nozzle opening is positioned coaxially with respect to the center of the semiconductor wafer. Jet plating equipment .

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