Patent Application
20090218231
The present invention relates to a plating apparatus for carrying out plating of a surface of a plating workpiece to be plated, such as a substrate, and more particularly to a plating apparatus for forming a plated film in fine interconnect trenches or holes, via holes, through-holes, or resist openings formed in a surface of a semiconductor wafer or the like, or for forming a bump (protruding electrode), which provides electrical connection with an electrode of a package or the like, on a surface of a semiconductor wafer.
In TAB (Tape Automated Bonding) or FC (Flip Chip), for example, it has widely been practiced to form protruding connecting electrodes (bumps) of gold, copper, solder, lead-free solder, or nickel, or a multi-layer laminate of these metals at predetermined portions (electrodes) on a surface of a semiconductor chip having interconnects formed therein, and to electrically connect the interconnects via the bumps with electrodes of a package or with TAB electrodes. Methods of forming bumps include various methods, such as electroplating, vapor deposition, printing, and ball bumping. With a recent increase in the number of I/O in a semiconductor chip and a trend toward finer pitches, electroplating has more frequently been employed because it can cope with fine processing and has relatively stable performance.
With an electroplating method, a metal film (plated film) having a high purity can readily be obtained. Further, an electroplating method has a relatively high deposition rate of a metal film, and control of thickness of the metal film can be performed relatively easily.
In operation, a substrate W held horizontally by the substrate holder 14 is located at a position such as to close an opening at an upper end of the plating tank 12. In this state, the plating solution 10 is supplied from the plating solution supply nozzle 20 into the plating solution tank 12 and allowed to overflow the upper portion of the plating tank 12, thereby bringing the plating solution 10 into contact with a surface of the substrate W held by the substrate holder 14. Simultaneously, the anode 16 is connected via a conductor 22a to an anode of a plating power supply 24, and the substrate W is connected via a conductor 22b to a cathode of the plating power supply 24. Thus, due to a potential difference between the substrate W and the anode 16, metal ions in the plating solution 10 receive electrons from the surface of the substrate W, so that metal is deposited on the surface of the substrate W so as to form a metal film.
According to the plating apparatus, uniformity of the thickness of the metal film formed on the surface of the substrate W can be adjusted to a certain extent by adjusting the size of the anode 16, an interpolar distance and potential difference between the anode 16 and the substrate W, a supply rate of the plating solution 10 supplied from the plating solution supply nozzle 20, and the like.
In operation, the anode 16a, the substrate W, and the regulation plate 28 are immersed in the plating solution in the plating tank 12a. Simultaneously, the anode 16a is connected via a conductor 22a to an anode of a plating power supply 24, and the substrate W is connected via a conductor 22b to a cathode of the plating power supply 24. Accordingly, metal is deposited onto the surface of the substrate W so as to form a metal film in the same manner as described above.
According to the plating apparatus, distribution of thickness of the metal film formed on the surface of the substrate W can be adjusted to a certain extent by disposing the regulation plate 28 having the central hole 28a between the anode 16a and the substrate W disposed at a position facing the anode 16a, and adjusting a potential distribution on the plating bath 12a with the regulation plate 28.
According to the plating apparatus, uniformity of thickness of a plated film formed on the surface of the substrate W can be improved by adjusting an electric potential of the dummy cathode 30.
On the other hand, for example, when a metal film (plated film) for interconnects or bumps is formed on a surface of a semiconductor substrate (wafer), the metal film formed is required to be uniform in surface profile and in film thickness over the entire surface of the substrate. There are increasing demands for a high degree of uniformity in recent high-density packaging technologies such as SOC and WL-CSP. However, with the above conventional plating apparatuses, it is quite difficult to form a metal film that meets a high degree of uniformity requirement.
Specifically, when a substrate is plated by the plating apparatus shown in
In the conventional plating apparatuses, there is a general tendency that due to a surface potential distribution produced over a surface of a substrate, the film thickness of a plated film is larger in a peripheral portion of the substrate, which serves as an electrically receiving portion, causing a U-shaped film thickness distribution over the substrate surface (see
The regulating method of a flow of a plating solution and the regulating method using a regulation plate are intended to concentrate metal ions or an electric field to a central portion of a substrate to raise a plated film at the central portion of the substrate, thereby adjusting a film thickness distribution of the plated film over the entire substrate surface so as to be a W-shaped distribution and minimizing a film thickness variation from an average film thickness (see
On the other hand, the method using a dummy electrode is intended to broaden a range of a potential distribution from a substrate surface to a region including the dummy electrode around the substrate, thereby shifting the raised portion of the plated film in the electrically receiving portion to the dummy electrode and obtaining an extremely uniform film thickness on the substrate surface. As an equivalent method to the method employing a dummy electrode, there has also been known a method which uses a pattern in a peripheral portion of a substrate as a “discarded chip” so as to serve as a dummy electrode. In such methods that employ a dummy electrode, the uniformity of the film thickness is influenced by adjustment of a voltage. Further, it is necessary to periodically remove a metal film (plated film) attached to the dummy electrode, which necessitates a troublesome operation. When a pattern in a peripheral portion of a substrate is used as a “discarded chip” so as to serve as a dummy electrode, the number of effective chips per substrate is inevitably reduced to thereby cause a lowered productivity.
All of the above-described methods eventually adjust a film thickness distribution to obtain a uniform film thickness distribution. Thus, none of the above-described methods are intended to positively control or regulate an electric field in a plating tank, which is produced between an anode and a plating workpiece as a cathode, so as to control and improve a potential distribution on a surface of the plating workpiece, thereby equalizing and improving the film thickness distribution of the plated film which would otherwise become a U-shaped distribution.
The present invention has been made in view of the above drawback. It is, therefore, an object of the present invention to provide a plating apparatus which can form a metal film (plated film) having a uniform thickness over an entire plating workpiece with a relatively simple arrangement and without needs for a complicated operation and setting.
In order to achieve the above object, the present invention provides a plating apparatus characterized by comprising a plating tank for holding a plating solution; an anode disposed so as to be immersed in the plating solution in the plating tank; a regulation plate disposed between the anode and a plating workpiece disposed so as to face the anode; and a plating power supply for supply a current between the anode and the plating workpiece to carry out plating, wherein the regulation plate is disposed so as to separate the plating solution held in the plating tank into a plating solution on the anode side and a plating solution on the plating workpiece side, and a through-hole group having a large number of through-holes is formed in the regulation plate.
According to the present invention, an electric field leaks through a large number of through-holes formed in the regulation plate disposed in the plating tank, and the leaked electric field spreads uniformly. Accordingly, a potential distribution can be made more uniform over an entire surface of the plating workpiece, and a within wafer uniformity of a metal film formed on the surface of the plating workpiece can be enhanced. Further, the plating solution is prevented from passing through a large number of through-holes formed in the regulation plate provided in the plating tank. Accordingly, a non-uniform metal film thickness is prevented from being formed on the surface of the plating workpiece due to influence of a flow of the plating solution.
According to a preferred aspect of the present invention, the through-hole group is formed by a plurality of slit-like elongated holes extending linearly in one direction or extending in an arc. The use of slit-like elongated holes as the through-holes can promote leakage of electric field while preventing the plating solution from passing through the through-holes. For example, the widths of the elongated holes are set to be about 0.5 to 20 mm, preferably about 1 to 15 mm. The lengths of the elongated holes are determined depending upon the shape of the plating workpiece.
According to a preferred aspect of the present invention, the through-hole group is formed by a plurality of cross holes extending crosswise in vertical and horizontal directions.
According to a preferred aspect of the present invention, the through-hole group is formed by a combination of a plurality of fine holes, a plurality of holes having different diameters, and slit-like elongated holes. The use of a combination of a plurality of fine holes, a plurality of holes having different diameters, and slit-like elongated holes as the through-hole group can increase the productivity. For example, the diameters of the fine holes or small holes (peripheral holes) are set to be about 1 to 20 mm, preferably about 2 to 10 mm. For example, the diameters of large holes (central holes) are set to be about 50 to 300 mm, preferably about 30 to 100 mm.
It is desirable that the through-hole group be formed in the regulation plate substantially over an entire area facing the plating workpiece, and formed in an area substantially similar to a shape of the plating workpiece. With such a through-hole group, it is possible to form a metal film having a good film thickness uniformity in all directions on the plating workpiece.
Preferably, the plating apparatus comprises an agitating mechanism provided between the plating workpiece and the regulation plate for stirring the plating solution held in the plating tank. By agitating the plating solution between the plating workpiece and the regulation plate by the agitating mechanism during plating, sufficient ions can be supplied more uniformly to the plating workpiece. Therefore, a metal film having a more uniform thickness can be formed more rapidly.
Preferably, the agitating mechanism should comprise a paddle-type agitating mechanism having a paddle which reciprocates parallel to the plating workpiece. By reciprocating a paddle parallel to the plating workpiece during plating to agitate the plating solution by the paddle, the directionality of the flow of the plating solution can be eliminated, and simultaneously sufficient ions can be supplied more uniformly to the surface of the plating workpiece.
According to a preferred aspect of the present invention, the anode and the regulation plate are provided in a vertical direction. This arrangement provides a plating apparatus with a small installation space and having excellent maintainability.
The present invention also provides another plating apparatus characterized by comprising a plating tank for holding a plating solution; an anode disposed so as to be immersed in the plating solution in the plating tank; a regulation plate disposed between the anode and a plating workpiece disposed so as to face the anode; and a plating power supply for supply a current between the anode and the plating workpiece to carry out plating, wherein the regulation plate is disposed so as to separate the plating solution held in the plating tank into a plating solution on the anode side and a plating solution on the plating workpiece side, and a plating solution passage is formed in the regulation plate for allowing an electric field to uniformly pass therethrough and allowing the plating solution to pass therethrough.
By thus allowing the electric field produced between the anode and the plating workpiece in the plating tank to pass uniformly through the plating solution passage without leaking out of the plating solution passage, distortion or deviation of the electric field can be adjusted and corrected so as to equalize a potential distribution over an entire surface of the plating workpiece, thereby enhancing a within wafer uniformity of a metal film formed on the plating workpiece.
The length of the plating solution passage is properly determined depending upon the shape of the plating tank, the distance between the anode and the plating workpiece, and the like. However, the length is generally 10 to 90 mm, preferably 20 to 75 mm, more preferably 30 to 60 mm.
Preferably, the plating solution passage is defined by an inner circumferential surface of a cylindrical member or a rectangular block. This arrangement can simplify the structure.
It is desirable that a large number of through-holes having a size such as to prevent leakage of an electric field be formed in a circumferential wall of the cylindrical member. With this arrangement, the plating solution is allowed to pass through the through-holes formed in the circumferential wall of the cylindrical member while preventing leakage of the electric field. Accordingly, the concentration of the plating solution is prevented from being different between the inside and outside of the cylindrical member. With respect to the shape of the through-holes, for example, fine holes, slit-like elongated holes, cross holes extending vertically and horizontally, and a combination thereof may be exemplified.
According to a preferred aspect of the present invention, the plating apparatus comprises an agitating mechanism provided in at least one of a space between the plating workpiece and the regulation plate and a space between the anode and the regulation plate for agitating the plating solution held in the plating tank. By agitating the plating solution during plating, the concentration of the plating solution containing metal ions and various additives can be made uniform in the plating tank, and the plating solution having a uniform concentration can be supplied to the plating workpiece. Accordingly, a metal film having a more uniform thickness can be formed more rapidly.
The agitating mechanism is preferably a paddle-type agitating mechanism having a paddle which reciprocates parallel to the plating workpiece.
The agitating mechanism may comprise a plating solution injection type agitating mechanism having a plurality of plating solution injection nozzles for ejecting the plating solution toward the plating workpiece. By injecting the plating solution from the plurality of plating solution injection nozzles toward the plating workpiece, the plating solution in the plating tank can be agitated so as to uniformize the plating solution concentration and, simultaneously, to sufficiently supply components of the plating solution to the plating workpiece. Thus, a metal film having a more uniform thickness can be formed more rapidly.
The plating solution passage may be formed in the regulation plate integrally with the regulation plate. A thick regulation plate may be used, and a through-hole may be formed in the regulation plate so as to serve as a plating solution passage.
The present invention provides yet another plating apparatus comprising a plating tank for holding a plating solution; an anode disposed so as to be immersed in the plating solution in the plating tank; a regulation plate disposed between the anode and a plating workpiece disposed so as to face the anode for separating the plating solution held in the plating tank into a plating solution on the anode side and a plating solution on the plating workpiece side, the regulation plate having a plating solution passage for allowing an electric field to uniformly pass therethrough and allowing the plating solution to pass therethrough; a plating power supply for supply a current between the anode and the plating workpiece to carry out plating; and an electric field adjustment ring disposed at an end of the plating solution passage on the plating workpiece side for adjusting an electric field at a peripheral portion of the plating workpiece.
By adjusting an electric field at a peripheral portion of the plating workpiece by the electric field adjustment ring, an electric field produced between the anode and the plating workpiece can be uniformized over an entire surface of the plating workpiece, including an edge portion of the plating workpiece, which serves as an electrically receiving portion. Therefore, a within wafer uniformity of a metal film formed on the plating workpiece can be further enhanced.
The shape of the electric field adjustment ring may be properly determined depending upon the shape of the plating tank, the shape of the plating workpiece, the distance between the anode and the plating workpiece, and the like. The width of the ring is generally set to be in a range of 1 to 20 mm, preferably 3 to 17 mm, more preferably 5 to 15 mm.
A gap between the electric field adjustment ring and the plating workpiece is generally set to be in a range of 0.5 to 30 mm, preferably 1 to 15 mm, more preferably 1.5 to 6 mm.
According to a preferred aspect of the present invention, the plating solution passage is defined by an inner circumferential surface of a cylindrical member, and the electric field adjustment ring is connected to an end of the cylindrical member on the plating workpiece side.
Alternatively, the plating solution passage may be defined by an inner circumferential surface of a cylindrical member, and the electric field adjustment ring may be disposed at an end of the cylindrical member on the plating workpiece side so as to be separated from the cylindrical member. With such a separated plating solution passage, the cylindrical member and the electric field adjustment ring can be separated so as to offer a broader choice.
Alternatively, the plating solution passage may be defined by an inner circumferential surface of a cylindrical member, and the electric field adjustment ring may be formed on an end surface of the plating workpiece side. With this arrangement, the number of parts can be reduced.
Embodiments of the present invention will be described below with reference to the drawings. The following embodiments show examples in which a substrate such as a semiconductor wafer is used as a plating workpiece.
In the clean space 114, there are disposed at four corners an aligner 122 for aligning an orientation flat or a notch of a substrate with a predetermined direction, two cleaning/drying devices 124 for cleaning a plated substrate and rotating the substrate at a high speed to spin-dry the substrate, and a pretreatment device 126 for carrying out a pretreatment of a substrate, e.g., according to the present embodiment, a rinsing pretreatment including injecting pure water toward a front face (surface to be plated) of a substrate to thereby clean the substrate surface with pure water and, at the same time, wet the substrate surface with pure water so as to enhance a hydrophilicity of the substrate surface. Further, a first transfer robot 128 is disposed substantially at the center of these processing devices, i.e. the aligner 122, the cleaning/drying devices 124, and the pretreatment device 126, to thereby transfer and deliver a substrate between the processing devices 122, 124, and 126, the substrate attachment/detachment stages 162, and the substrate cassettes mounted on the loading/unloading ports 120.
The aligner 122, the cleaning/drying devices 124, and the pretreatment device 126 disposed in the clean space 114 are designed so as to hold and process a substrate in a horizontal state in which a front face of the substrate faces upward. The transfer robot 128 is designed so as to transfer and deliver a substrate in a horizontal state in which a front face of the substrate faces upward.
In the plating space 116, in order from the partition plate 112, there are disposed a stocker 164 for storing or temporarily storing the substrate holders 160, an activation treatment device 166 for etching, for example, an oxide film, having a large electric resistance, on a seed layer formed on a surface of a substrate with a chemical liquid such as sulfuric acid or hydrochloric acid to remove the oxide film, a first rinsing device 168a for rinsing the surface of the substrate with pure water, a plating apparatus 170 for carrying out plating, a second rinsing device 168b, and a blowing device 172 for dewatering the plated substrate. Two second transfer robots 174a and 174b are disposed beside these devices so as to be movable along a rail 176. One of the second transfer robots 174a transfers the substrate holders 160 between the substrate attachment/detachment stages 162 and the stocker 164. The other of the second transfer robots 174b transfers the substrate holders 160 between the stocker 164, the activation treatment device 166, the first rinsing device 168a, the plating apparatus 170, the second rinsing device 168b, and the blowing device 172.
As shown in
The stocker 164, the activation treatment device 166, the rinsing devices 168a, 168b, and the plating apparatus 170 are designed so as to engage with outwardly projecting portions 160a provided at both ends of each substrate holder 160 to thus support the substrate holders 160 in a state such that the substrate holders 160 are suspended in a vertical direction. The activation treatment device 166 has two activation treatment tanks 183 for holding a chemical liquid therein. As shown in
Similarly, the rinsing devices 168a and 168b have two rinsing tanks 184a and two rinsing tanks 184b which hold pure water therein, respectively, and the plating apparatus 170 has a plurality of plating tanks 186 which hold a plating solution therein. The rinsing devices 168a, 168b and the plating apparatus 170 are designed so that the substrate holders 160 are immersed together with the substrates W in the pure water in the rinsing tanks 184a, 184b or the plating solution in the plating tanks 186 to carry out rinsing treatment or plating in the same manner as described above. The arm 180 of the second transfer robot 174b holding the substrate holders 160 with substrates W in a vertical state is lowered, and air or inert gas is injected toward the substrates W mounted on the substrate holders 160 to blow away a liquid attached to the substrate holders 160 and the substrates W and to dewater the substrates W. Thus, the blowing device 172 is designed so as to carry out blowing treatment.
As show in
Overflow tanks 46 are provided at both sides of the plating tank 186 for receiving a plating solution 10 overflowing upper ends of overflow weirs 44 of the plating tank 186. The overflow tanks 46 and the plating tank 186 are connected through a circulation pipe 48. The circulation pipe 48 has a circulating pump 50, a thermostatic unit 52, and a filter 54 provided in the circulation pipe 48. A plating solution 10 supplied into the plating tank 186 by operation of the circulating pump 50 fills the plating tank 186, then overflows the overflow weirs 44, flows into the overflow tanks 46, and returns to the circulating pump 50. Thus, the plating solution 10 is circulated.
An anode 56 having a circular shape corresponding to the shape of the substrate W is held by an anode holder 58 and provided vertically in the plating tank 186. Thus, when the plating solution 10 is filled in the plating tank 186, the anode 56 is immersed in the plating solution 10. Further, a regulation plate 60 is provided between the anode 56 and the substrate holder 160 to partition the interior of the plating tank 186 into an anode side chamber 40a and a substrate side chamber 40b and to separate the plating solution 10 held in the plating tank 186 into an anode side plating solution and a substrate side plating solution.
A paddle-type agitating mechanism 64 having a plurality of paddles 62 extending vertically downward is disposed between the substrate holder 160 and the regulation plate 60. The paddles 62 are reciprocated within the plating solution in the substrate side chamber 40b in parallel to the substrate W held by the substrate holder 160, thereby stirring the plating solution in the substrate side chamber 40b.
The regulation plate 60 has a thickness of, for example, about 0.5 to 10 mm and is made of a dielectric material including PVC, PP, PEEK, PES, HT-PVC, PFA, PTFE, and other resin materials. A through-hole group 68 including a large number of through-holes 66 is provided in a predetermined area of the regulation plate 60, which is substantially the entire area facing the surface of the substrate W when the substrate W is held by the substrate holder 160 and located at a predetermined plating position in the plating tank 186, and which is a circular area similar to the shape of the substrate W.
According to the present embodiment, as particularly shown in
Thus, the through-hole group 68 including a large number of through-holes 66 is provided in the regulation plate 60 so that an electric field leaks through the respective through-holes 66 at the time of plating, and so that the leaked electric field spreads uniformly. Accordingly, a potential distribution can be made more uniform over the entire surface (surface to be plated) of the substrate W, and a within wafer uniformity of a metal film formed on the surface of the substrate W can be enhanced. Further, the plating solution 10 is prevented from passing through a large number of through-holes 66 formed in the regulation plate 60 provided in the plating tank 186. Accordingly, a non-uniform metal film thickness is prevented from being formed on the surface of the substrate W due to influence of a flow of the plating solution 10 (return flow of the plating solution).
Particularly, the use of slit-like elongated holes as the through-holes 66 can prevent the plating solution 10 from passing through the through-holes (elongated holes) 66 and simultaneously promote leakage of the electric field. Further, by forming the through-hole group 68, including a large number of through-holes 66 (i.e., minimize the amount of plating solution passing through), substantially in the entire area facing the surface of the substrate W which is a circular area similar to the shape of the substrate W, a metal film having a good film thickness uniformity can be formed in all directions on the surface of the substrate W.
With the plating apparatus 170, a plating solution 10 is first filled in the plating tank 186 and circulated as described above. In this state, the substrate holder 160 holding the substrate W is lowered to locate the substrate W at a predetermined position within the plating tank 186 at which the substrate W is immersed in the plating solution 10. The anode 56 is connected via a conductor 22a to an anode of a plating power supply 24, and the substrate W is connected via a conductor 22b to a cathode of the plating power supply 24. At the same time, the paddle-type agitating mechanism 64 is operated so as to reciprocate the paddles 62 along the surface of the substrate W to thereby agitate the plating solution 10 in the substrate side chamber 40b. As a result, a metal is deposited on the surface of the substrate W so as to form a metal film on the surface of the substrate W.
At that time, as described above, an electric field leaks through a large number of through-holes 66 formed in the regulation plate 60, and the leaked electric field spreads uniformly. Accordingly, a potential distribution can be made more uniform over the entire front face (surface to be plated) of the substrate W, and a metal film P having an enhanced within wafer uniformity can be formed on the surface of the substrate W as shown in
After completion of the plating, the plating power supply 24 is disconnected from the substrate W and the anode 56, and the substrate holder 160 is pulled up together with the substrate W. After necessary treatments such as water-cleaning and rinsing of the substrate W, the plated substrate W is transferred to a subsequent process.
A series of bump plating processes in the plating facility thus constructed will be described below with reference to
One of the substrates W is taken out of the substrate cassette mounted on the loading/unloading port 120 by the first transfer robot 128 and placed on the aligner 122 to align an orientation flat or a notch of the substrate with a predetermined direction. The substrate W thus aligned is transferred to the pretreatment device 126 by the first transfer robot 128. In the pretreatment device 126, a pretreatment (rinsing pretreatment) using pure water as a pretreatment liquid is carried out. On the other hand, two substrate holders 160 which have been stored in a vertical state in the stocker 164 are taken out by the second transfer robot 174a, rotated through 90° so that the substrate holders 160 are brought into a horizontal state, and then placed in parallel on the substrate attachment/detachment stages 162.
Then, the substrates W which have been subjected to the aforementioned pretreatment (rinsing pretreatment) are loaded into the substrate holders 160 placed on the substrate attachment/detachment stages 162 in a state such that peripheral portions of the substrates are sealed. The two substrate holders 160 which have been loaded with the substrates W are simultaneously retained, lifted, and then transferred to the stocker 164 by the second transfer robot 174a. The substrate holders 160 are rotated through 90° into a vertical state and lowered so that the two substrate holders 160 are held (temporarily stored) in the stocker 164 in a suspended manner. The above operation is carried out repeatedly in a sequential manner, so that substrates are sequentially loaded into the substrate holders 160, which are stored in the stocker 164, and are sequentially held (temporarily stored) in the stocker 164 at predetermined positions in a suspended manner.
On the other hand, the two substrate holders 160 which have been loaded with the substrates and temporarily stored in the stocker 164 are simultaneously retained, lifted, and then transferred to the activation treatment device 166 by the second transfer robot 174b. Each substrate is immersed in a chemical liquid such as sulfuric acid or hydrochloric acid held in the activation treatment tank 183 to thereby etch an oxide film, having a large electric resistance, formed on the surface of the seed layer so as to expose a clean metal surface. The substrate holders 160 which have been loaded with the substrates are transferred to the first rinsing device 168a in the same manner as described above to rinse the surfaces of the substrates with pure water held in the rinsing tanks 184a.
The substrate holders 160 which have been loaded with the rinsed substrates are transferred to the plating apparatus 170 in the same manner as described above. Each substrate W is supported in a suspended manner by the plating tank 186 in a state such that the substrate W is immersed in the plating solution 10 in the plating tank 186 to thus carry out plating on the surface of the substrate W. After a predetermined period of time has elapsed, the substrate holders 160 which have been loaded with the substrates are retained again and pulled up from the plating tank 186 by the second transfer robot 174b. Thus, the plating process is completed.
Thereafter, the substrate holders 160 are transferred to the second rinsing device 168b in the same manner as described above. The substrate holders 160 are immersed in pure water in the rinsing tanks 184b to clean the surfaces of the substrates with pure water. Then, the substrate holders 160 which have been loaded with the substrates are transferred to the blowing device 172 in the same manner as described above. In the blowing device 172, inert gas or air is injected toward the substrates to blow away a plating solution and water droplets attached to the substrate holders 160. Thereafter, the substrate holders 160 which have been loaded with the substrates are returned to predetermined positions in the stocker 164 and held in a suspended state in the same manner as described above.
The second transfer robot 174b sequentially performs the above operation repeatedly so that the substrate holders 160 which have been loaded with the plated substrates are sequentially returned to predetermined positions in the stocker 164 and held in a suspended manner.
On the other hand, the two substrate holders 160 which have been loaded with the plated substrates are simultaneously retained and placed on the substrate attachment/detachment stages 162 by the second transfer robot 174a in the same manner as described above.
The first transfer robot 128 disposed in the clean space 114 takes the substrate out of the substrate holders 160 placed on the substrate attachment/detachment stages 162 and transfers the substrate to either one of the cleaning/drying devices 124. In the cleaning/drying device 124, the substrate held in a horizontal state such that the front face of the substrate faces upward is cleaned with pure water or the like and rotated at a high speed to spin-dry the substrate. Thereafter, the substrate is then returned to the substrate cassette mounted on the loading/unloading port 120 by the first transfer robot 128. Thus, a series of plating processes is completed. As a result, as shown in
The spin-dried substrate W as described above is immersed in a solvent such as acetone at a temperature of, for example, 50 to 60° C. to remove the resist 502 from the substrate W as shown in
According to this embodiment, delivery of substrates in the plating space 116 is performed by the second transfer robots 174a and 174b disposed in the plating space 116, whereas delivery of substrates in the clean space 114 is performed by the first transfer robot 128 disposed in the clean space 114. Accordingly, it is possible to improve the cleanliness around a substrate in the plating processing apparatus which performs all the plating processes including pretreatment of a substrate, plating, and post-treatment of the plating, in a successive manner, and to increase a throughput of the plating processing apparatus. Further, it is possible to reduce loads on facilities associated with the plating processing apparatus and to achieve downsizing of the plating processing apparatus.
According to the present embodiment, a plating tank 186 having a small footprint is used in the plating apparatus 170 for carrying out plating. Accordingly, it is possible to achieve further downsizing of the plating apparatus having a large number of plating tanks 186 and reduce loads on associated facilities in a plant. In
Thus, a through-hole group is formed by a combination of a plurality of through-holes having desired shapes, such as a plurality of fine holes, a plurality of holes having different diameters, and slit-like elongated holes. Accordingly, a through-hole group can meet various requirements regarding plating sites, plating conditions, and the like.
In the examples shown in
As described above, according to the present invention, an electric field leaks through a large number of through-holes formed in a regulation plate provided in the plating tank, and the leaked electric field spreads uniformly. Accordingly, a potential distribution can be made more uniform over the entire surface of a plating workpiece, and a within wafer uniformity of a metal film formed on the surface of the plating workpiece can be enhanced. Further, a plating solution is prevented from passing through a large number of through-holes formed in the regulation plate provided in the plating tank 186. Accordingly, non-uniform metal film thickness is prevented from being formed on the surface of the plating workpiece due to influence of a flow of the plating solution.
The inside diameters D of the central hole of the regulation plate 60 and the cylindrical member 200 are generally set to be approximately in a range of ±10 mm of an outside diameter (plated surface outside diameter) of a surface of a substrate W to be plated, preferably in a range of ±5 mm of an outside diameter of a surface to be plated, more preferably in a range of ±1 mm of an outside diameter of a surface to be plated. The length L of the cylindrical member 200 may properly be set depending upon the shape of the plating tank 186, the distance between the anode 56 and the substrate W, and the like. However, the length L is generally set to be in a range of 10 to 90 mm, preferably 20 to 75 mm, more preferably 30 to 60 mm.
Thus, an electric field produced between the anode 56 and the substrate W in the plating tank 186 passes along the plating solution passage 200a, i.e., passes uniformly through the cylindrical member 200 without leaking out of the cylindrical member 200. Accordingly, distortion and deviation of the electric field can be adjusted and corrected so as to equalize a potential distribution over the entire surface of the substrate W. As a result, as shown in
Specifically, a regulation plate 60 generally is as thin as about 0.5 to 10 mm. Therefore, with a regulation plate 60 having only a central hole 60a formed therein, an electric field produced between the anode 56 and a substrate W in the plating tank 186 is not sufficiently regulated, and distortion or deviation of an electric field is caused. Accordingly, the substrate tends to be thicker at an edge portion, which serves as an electrically receiving portion. According to the present example, passing of an electric field is regulated over the length L of the cylindrical member 200, so that the above drawback is solved. Thus, a within wafer uniformity of a metal film can be enhanced.
In this example, as in the examples shown in
Thus, the plating solution 10 is injected from a plurality of plating solution injection nozzles 206 toward the substrate W. Accordingly, the plating solution 10 in the plating tank 186 can be agitated so as to make the plating solution concentration uniform and, simultaneously, to sufficiently supply components of the plating solution 10 to the substrate W. Thus, a metal film having a more uniform thickness can be formed more rapidly.
In this example, the cylindrical member 200 is coupled to a surface of the regulation plate 60 on the substrate W side. However, as shown in
Further, as shown in
Further, as shown in
Furthermore, as shown in
As with the regulation plate 60 and the cylindrical member 200, the electric field adjustment ring 220 is made of a dielectric material including PVC, PP, PEEK, PES, HT-PVC, PFA, PTFE, and other resin materials. Other elements of the construction are the same as those shown in
The electric field adjustment ring 220 serves to adjust an electric field at a peripheral portion of the substrate W by covering a location near a peripheral portion of a substrate W over a predetermined width. Thus, an electric field is adjusted at a peripheral portion of the substrate W. Accordingly, an electric field produced between the anode 56 and the substrate W can be made uniform over the entire surface of the substrate W, including an edge portion of the substrate W, which serves as an electrically receiving portion. Therefore, as shown in
Thus, the plating solution injection type agitating mechanism 202 is disposed in the anode side chamber 40a, and the plating solution is injected from the plating solution injection nozzles 206 toward the plating solution passage 200a of the cylindrical member 200. The plating solution can be supplied through the plating solution passage 200a to the substrate W held by the substrate holder 160 even if a gap G1 between an electric field adjustment ring 220 and the substrate W held by the substrate 160 is narrow.
As shown in
As shown in
Further, as shown in
As shown in
Although the aforementioned examples show that the present invention is applied to a so-called dipping type plating apparatus, the present invention is also applicable to a face-down type plating apparatus or a face-up type plating apparatus.
An electric field adjustment ring having an inside diameter equal to an inside diameter of the cylindrical member and a predetermined width may concentrically be attached to an upper end surface of the cylindrical member so as to cover a location near a peripheral portion of the substrate W over a predetermined width. Thus, an electric field can be adjusted at the peripheral portion of the substrate W. Accordingly, an electric field produced between the anode 56 and the substrate can be made uniform over the entire surface of the substrate, including an edge portion of the substrate, which serves as an electrically receiving portion. Therefore, a metal film having an enhanced within wafer uniformity can be formed on the surface of the substrate, including the edge portion of the substrate.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2002-210097 | Jul 2002 | JP | national |
This application is a divisional of U.S. application Ser. No. 10/485,350, filed Aug. 19, 2004, which is a national stage application of International application No. PCT/JP03/09144, filed Jul. 18, 2003.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10485350 | Aug 2004 | US |
| Child | 12453347 | US |
