JP2012031453A - Device and method for electroless plating treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve both the electrode quality of a semiconductor wafer and the workability.SOLUTION: The invention relates to an electroless plating treatment device 1 for forming an electrode by applying electroless plating treatment to a silicon wafer W in a treatment chamber 10A inside a light shielding housing 10. In the electroless plating device 1, the treatment chamber 10A includes a treatment chamber light 12 capable of emitting a visible light whose photoelectromotive force generated when the silicon wafer W is irradiated with the light is less than a predetermined value.

Description

  The present invention relates to an electroless plating apparatus and an electroless plating method, and more particularly to an electroless plating apparatus and an electroless plating method for forming electrodes on a semiconductor wafer.

  In recent years, an electroless plating process has been used as a method for forming electrodes on a semiconductor wafer at low cost and high accuracy without using an expensive vacuum device used for sputtering or the like, or an expensive drawing device used for photolithography or the like. A method has been proposed.

  For example, Patent Document 1 discloses a method of performing plating with nickel cheaper than gold and further performing thin gold plating on the surface as an electroless plating method for forming electrodes on a silicon wafer. .

  However, in the electroless plating method disclosed in Patent Document 1, when an electrode is formed on a silicon wafer on which an object such as an active element that can generate photovoltaic power is formed, the height of the formed electrode varies. There was a problem. That is, the problem is that the thickness of the deposited plating becomes non-uniform due to the influence of the photovoltaic power generated inside the silicon wafer exposed to light, resulting in variations in the thickness or height of the formed electrode. was there.

  With respect to this problem, Patent Document 2 discloses a method of performing electroless plating treatment in a state where photovoltaic power is removed.

  FIG. 6A is a perspective view showing the appearance of the apparatus 101 that performs the electroless plating method described in Patent Document 2, and FIG. 6B is a diagram of the apparatus 101 shown in FIG. It is a perspective view which shows an internal structure. As shown in FIGS. 6A and 6B, according to the plating method described in Patent Document 2, the silicon wafer W is completely shielded from light inside the light shielding casing 110 included in the apparatus 101. Perform electroless plating. Thereby, since the influence of the photovoltaic power is eliminated, the height of the electrodes formed on the silicon wafer W can be made uniform.

Japanese Patent Laid-Open No. 2001-237267 (released on August 31, 2001) JP 2000-150422 A (published on May 30, 2000)

  However, the electroless plating method described in Patent Document 2 can eliminate the influence of the photovoltaic force by performing the electroless plating process in a completely light-shielded state, but has the following problems. .

  For example, when a facility trouble occurs during the electroless plating process, in order to limit the generation of photovoltaic power due to light reception, it is necessary to restore the facility while maintaining the light shielding state of the light shielding casing 110. Therefore, it is necessary to separately use an instrument such as an infrared scope, and workability is significantly reduced.

  On the other hand, from the viewpoint of workability, when the light shielding state of the light shielding casing 110 is once released and the work is performed, a photoelectromotive force is generated inside the silicon wafer W exposed to light. Variations will occur.

  The present invention has been made in view of such conventional problems, and an object thereof is to realize an electroless plating processing apparatus and an electroless plating processing method that achieve both the electrode quality and workability of a semiconductor wafer. There is.

  In order to solve the above problems, an electroless plating apparatus according to the present invention provides an electroless plating apparatus for forming an electrode by performing an electroless plating process on a semiconductor wafer in a processing chamber inside a light shielding housing. The chamber includes a first light source capable of irradiating the first visible light whose photovoltaic power generated when irradiating the semiconductor wafer is a predetermined value or less.

  Further, an electroless plating method according to the present invention is an electroless plating method for forming an electrode by performing an electroless plating process on a semiconductor wafer in a processing chamber maintained in a light-shielded state in order to solve the above-described problem. The semiconductor wafer includes an irradiating step of irradiating the semiconductor wafer with visible light whose photovoltaic power generated when irradiating the semiconductor wafer is a predetermined value or less.

  According to the above invention, the processing chamber inside the light shielding case maintained in the light shielding state is capable of irradiating the first visible light whose photovoltaic power generated when irradiating the semiconductor wafer is equal to or less than a predetermined value. It has a light source. For this reason, for example, when an equipment trouble occurs when the electroless plating process is executed, the first visible light is irradiated by the first light source, so that a conventional instrument such as an infrared scope is used separately, or It is possible to visualize the processing chamber and visually perform the restoration work of the equipment without releasing the light shielding state for the restoration work of the equipment. Thereby, workability | operativity can be improved.

  In addition, the first visible light is controlled so that the photovoltaic power generated when the semiconductor wafer is irradiated is equal to or less than a predetermined value. For this reason, even if it is a case where 1st visible light is irradiated, since the height variation of the electrode formed in a semiconductor wafer can be suppressed, it is possible to ensure electrode quality.

  As described above, according to the above-described invention, it is possible to realize an electroless plating apparatus and an electroless plating method that achieve both the electrode quality and workability of a semiconductor wafer.

  In the electroless plating apparatus according to the present invention, it is preferable that the first visible light has a wavelength of 500 nm to 780 nm and an illuminance of more than 0 lx and 10 lx or less.

  In the electroless plating method according to the present invention, the visible light preferably has a wavelength of 500 nm or more and 780 nm or less, and an illuminance of more than 0 lx and 10 lx or less.

  According to the above invention, the first visible light (visible light) has a wavelength of 500 nm or more and 780 nm or less, and the illuminance is controlled to be more than 0 lx and 10 lx or less.

  In order to visualize the processing chamber, the wavelength of the first visible light needs to be in the range of 380 nm or more and 780 nm or less, which is the visible light region. On the other hand, in order to limit the photovoltaic power generated when irradiating the semiconductor wafer to a predetermined value or less, it is preferable that the first visible light has a wavelength as long as possible. Here, the correlation between the wavelength and the light energy is almost in the stable region when the wavelength is 500 nm or more in the visible light region. Therefore, 500 nm was selected as the lower limit value of the wavelength of the first visible light, and the wavelength of the first visible light was selected in the range of 500 nm or more and 780 nm or less.

  Moreover, in order to suppress the variation in the height of the electrodes formed on the semiconductor wafer by setting the photovoltaic force generated when irradiating the semiconductor wafer to a predetermined value or less, it is preferable to set the illuminance as low as possible. Here, as for the correlation between the illuminance and the height variation width of the electrode, when the illuminance becomes 10 lx or less, the variation width of the electrode becomes ± 2% or less. Therefore, 10 lx was selected as the upper limit value of the illuminance of the first visible light, and the illuminance of the first visible light was selected in the range of more than 0 lx and 10 lx or less.

  In this way, by controlling the wavelength to be 500 nm or more and 780 nm or less and the illuminance to be greater than 0 lx and 10 lx or less, the first visible light in which the photovoltaic power generated when the semiconductor wafer is irradiated is equal to or less than a predetermined value is realized. be able to.

  In the electroless plating apparatus according to the present invention, it is preferable that the first light source can adjust the wavelength and the illuminance.

  According to the above invention, since the first light source can adjust the wavelength and the illuminance, it is possible to irradiate visible light having a wavelength or illuminance different from that of the first visible light as necessary.

  Thereby, the 1st light source can irradiate optimal visible light according to the processing condition in a processing chamber.

  In the electroless plating apparatus according to the present invention, it is preferable that the first light source can irradiate second visible light having higher illuminance than the first visible light.

  According to the above invention, the first light source can irradiate the second visible light having higher illuminance than the first visible light. When the electroless plating process is not performed, such as during a maintenance operation, the semiconductor wafer is not yet carried into the processing chamber, and it is not necessary to consider the generation of photovoltaic power. For this reason, the process chamber can be illuminated more brightly by irradiating the first light source with the second visible light having higher illuminance than the first visible light.

  Thereby, workability | operativity at the time of the maintenance work of an electroless-plating processing apparatus etc. can be improved.

  The electroless plating apparatus according to the present invention further includes a front chamber that is maintained in a light-shielded state and allows observation of the inside of the processing chamber. The front chamber is a photovoltaic power generated when the semiconductor wafer is irradiated. It is preferable to include a second light source capable of irradiating third visible light having a value equal to or less than a predetermined value.

  According to the above invention, since the inside of the processing chamber can be observed from the front chamber, for example, if the electroless plating process is performed while irradiating the first visible light, the progress of the electroless plating process, or The equipment state and the like can be visually monitored. This enables early detection and early response to equipment troubles.

  Further, the second light source provided in the front chamber maintained in a light-shielded state can irradiate the third visible light whose photovoltaic power generated when irradiating the semiconductor wafer is not more than a predetermined value. Therefore, even when the third visible light is incident on the processing chamber from the front chamber when the electroless plating process is performed, the photovoltaic power generated in the semiconductor wafer can be limited to a predetermined value or less. Thereby, the deterioration of the electrode quality of the semiconductor wafer can be prevented.

  In the electroless plating apparatus according to the present invention, the third visible light preferably has a wavelength of 500 nm or more and 780 nm or less and an illuminance of more than 0 lx and 10 lx or less.

  According to the above invention, the third visible light is controlled to have a wavelength of 500 nm or more and 780 nm or less, and an illuminance of more than 0 lx and 10 lx or less. For this reason, even when the third visible light enters the processing chamber from the front chamber, the photovoltaic power generated in the semiconductor wafer can be limited to a predetermined value or less.

  Thereby, the 3rd visible light whose photovoltaic power generated at the time of irradiation to a semiconductor wafer is below a predetermined value is realizable.

  In the electroless plating apparatus according to the present invention, the semiconductor wafer is preferably made of silicon.

  According to the said invention, the electroless-plating processing apparatus which made the electrode quality and workability | operativity of the silicon wafer compatible is realizable.

  As described above, the electroless plating apparatus according to the present invention is an electroless plating apparatus that forms an electrode by performing an electroless plating process on a semiconductor wafer in a processing chamber inside a light shielding casing. A first light source capable of irradiating the first visible light whose photovoltaic power generated when irradiating the semiconductor wafer is equal to or less than a predetermined value is provided.

  Further, the electroless plating method according to the present invention is an electroless plating method in which an electrode is formed by subjecting a semiconductor wafer to electroless plating in a processing chamber maintained in a light-shielded state. It is a method including an irradiation step of irradiating the semiconductor wafer with visible light whose generated photovoltaic power is a predetermined value or less.

  Therefore, an object is to realize an electroless plating apparatus and an electroless plating process method that achieve both the electrode quality and workability of a semiconductor wafer.

It is sectional drawing which shows the structure of the electroless-plating processing apparatus which concerns on this invention. It is a graph which shows the correlation of a wavelength and optical energy. It is a graph which shows correlation with illumination intensity and the height variation width of an electrode. It is a graph which shows an example of control of the wavelength and the illumination intensity of the light which the light for process rooms with which the electroless-plating processing apparatus concerning this embodiment is provided. It is a flowchart which shows the flow of the electroless-plating processing method which concerns on this embodiment. (A) is a perspective view which shows the external appearance of the apparatus which enforces the conventional electroless-plating processing method, (b) is a perspective view which shows the internal structure of the apparatus shown by (a).

  An embodiment of the electroless plating apparatus according to the present invention will be described below with reference to FIGS. In the present embodiment, a case will be described in which an electrode is formed on a silicon wafer having a structure such as a PN junction in which a predetermined electronic circuit is formed on a silicon substrate by the electroless plating apparatus according to the present invention.

(Configuration of electroless plating equipment)
FIG. 1 is a cross-sectional view showing a configuration of an electroless plating apparatus 1 according to this embodiment. As shown in FIG. 1, the electroless plating apparatus 1 corresponds to a light shielding casing 10 that covers the entire apparatus, a plurality of processing tanks 20 disposed inside the light shielding casing 10, and a plurality of processing tanks 20. And a transfer unit 30 for transferring the silicon wafer W. The interior of the light shielding housing 10 is divided into a processing chamber 10A and a front chamber 10B by a partition plate 11. The processing chamber 10A is provided with a processing chamber light (first light source) 12, and similarly, the front chamber 10B is provided with a front chamber light (second light source) 13.

  The light shielding casing 10 has an outer surface made of a light shielding material that blocks light from the outside. For this reason, the processing chamber 10A and the front chamber 10B are maintained in a light shielding state.

  The partition plate 11 divides the interior of the light shielding housing 10 into a processing chamber 10 </ b> A and a front chamber 10 </ b> B, and is made of the same light shielding material as the outer surface of the light shielding housing 10. The partition plate 11 is provided with an internal gate (not shown) that can be opened and closed in a sliding manner, and the processing chamber 10A and the front chamber 10B can enter and exit through the internal gate. The partition plate 11 is provided with an openable / closable observation window so that the inside of the processing chamber 10A can be observed from the front chamber 10B.

  The processing chamber 10A is a chamber that performs an electroless plating process on the silicon wafer W, and includes a processing tank 20, a transfer unit 30, and the like.

  The front chamber 10B is a room that prevents external light and contaminated air from directly entering the processing chamber 10A from the outside. The front chamber 10B is provided with an external gate (not shown) that communicates with the outside of the apparatus. The internal gate and the external gate are not opened at the same time, and it is possible to prevent external light and contaminated air that have entered the front chamber 10B from the outside when the external gate is opened from entering the processing chamber 10A. . Thereby, 10 A of process chambers can be maintained in a clean state.

  Further, from the front chamber 10B, the inside of the processing chamber 10A can be observed through an observation window provided in the partition plate 11, and the progress of the electroless plating process performed in the processing chamber 10A, or the equipment The status can be monitored.

  The processing chamber light 12 is a light source capable of adjusting the wavelength and illuminance of the light to be irradiated, and for example, an LED or the like can be suitably used. In order to irradiate the optimal light according to the work contents in the processing chamber, such as during the electroless plating process or during maintenance work, the processing chamber light 12 can be appropriately changed in the wavelength and illuminance of the irradiation light. it can.

  For example, the processing chamber light 12 is configured to limit the generation of photovoltaic power in the silicon wafer W to a predetermined value or less during execution of the electroless plating process, or the progress of the electroless plating process or the transfer unit 30 or the like. Visible light (first visible light) for visualizing the operating state (equipment state) is irradiated.

  On the other hand, the processing room light 12 irradiates visible light (second visible light) having relatively higher illuminance than that during execution of the electroless plating process in order to improve workability during maintenance work. Details of the adjustment of the wavelength and illuminance of the light irradiated by the processing chamber light 12 will be described later.

  The front chamber light 13 is a light source capable of adjusting the wavelength and illuminance of the light to be irradiated, as with the processing chamber light 12, and an LED or the like can be suitably used. The front chamber light 13 can irradiate visible light (third visible light) whose photovoltaic power generated when irradiating the silicon wafer W is a predetermined value or less. In this embodiment, the processing chamber light 12 is irradiated. It is controlled to irradiate light whose wavelength and illuminance are tuned. Accordingly, the processing chamber 10A and the front chamber 10B are irradiated with light having the same wavelength and illuminance by the processing chamber light 12 or the front chamber light 13, respectively.

  The plurality of treatment tanks 20 are a water tank for washing the silicon wafer W, a dilute nitric acid tank, a sodium hydroxide tank, a zincate tank for performing zincate treatment (Zn displacement plating), and a Ni tank for performing electroless plating treatment. And an Au bath for performing electroless plating. The plurality of treatment tanks 20 are arranged in a row and placed on a placement table 14 disposed in the treatment chamber 10A.

  The transfer unit 30 transfers the silicon wafer W between the plurality of processing tanks 20 to perform an electroless plating process. The transfer unit 30 supports a holder 31 that holds the silicon wafer W, a transfer arm 32 that hangs down so that the holder 31 can be moved up and down, a guide rail 33 that guides the movement of the transfer arm 32 in the horizontal direction, and the guide rail 33. And a support portion 34.

  The support portion 34 protrudes from the mounting table 14 on which the plurality of processing tanks 20 are mounted, and guides the holder 31 to move horizontally above the plurality of processing tanks 20 placed in a line. The rail 33 is supported. For this reason, the holder 31 holding the silicon wafer W can be controlled to move horizontally above the plurality of processing tanks 20 and stop right above the predetermined processing tank 20. Further, the transfer arm 32 hangs down the holder 31 so that the holder 31 can be moved up and down, whereby the silicon wafer W held by the holder 31 can be transferred between the baths and immersed in a predetermined processing bath 20.

  In this manner, the electroless plating apparatus 1 is a processing chamber light 12 that can adjust the wavelength and illuminance of light irradiated to the processing chamber 10A inside the light shielding casing 10 that performs the electroless plating process on the silicon wafer W. The processing room light 12 is configured to appropriately change the wavelength and illuminance of the light to be irradiated according to the work content.

  Here, in order to make the electrode quality and workability of the silicon wafer W compatible, the light irradiated from the processing chamber light 12 during the electroless plating process is limited to the generation of photovoltaic power and the processing chamber 10A. It is necessary to satisfy the two conditions of visualization at the same time.

  That is, if the light irradiated from the processing chamber light 12 is too strong when the electroless plating process is performed, a photovoltaic force is generated in the silicon wafer W, resulting in variations in the height of the formed electrodes. For this reason, the electrode quality of the silicon wafer W cannot be ensured.

  On the other hand, if the light emitted from the processing chamber light 12 is too weak when the electroless plating process is performed, visualization of the processing chamber 10A cannot be realized. In this case, when an equipment trouble occurs when the electroless plating process is performed, it is necessary to separately perform equipment restoration work using an instrument such as an infrared scope as in the conventional case, and workability is reduced. Further, since the progress of the electroless plating process in the processing chamber 10A or the operation state of the transfer unit 30 and the like cannot be monitored from the outside, there is a delay in finding and dealing with equipment troubles.

  Therefore, as a result of intensive studies, the present inventor has come up with an optimum range of wavelength and illuminance that can simultaneously satisfy the two conditions of limiting the generation of photovoltaic power and visualizing the processing chamber 10A. Hereinafter, the wavelength and illuminance of light to be irradiated will be described.

(Irradiation light wavelength and illuminance)
First, a description will be given of the range of the wavelength of light that is irradiated when the electroless plating process is performed.

  FIG. 2 is a graph showing the correlation between wavelength and light energy. In FIG. 2, the horizontal axis represents wavelength (nm) and the vertical axis represents light energy (eV).

  First, in order to visualize the processing chamber 10A, the wavelength of light emitted from the processing chamber light 12 needs to be in a range of 380 nm or more and 780 nm or less, which is a visible light region. On the other hand, as shown in FIG. 2, silicon (Si) used for the silicon wafer W generates photovoltaic power in response to light having a wavelength of 1060 nm or less, but light energy that induces generation of photovoltaic power. Tends to decrease as the wavelength of the irradiated light becomes longer.

  Therefore, if light having a wavelength as long as possible in the visible light region is irradiated, visualization of the processing chamber 10A can be realized while suppressing generation of photovoltaic power as much as possible.

  Here, when the wavelength is 500 nm or more, the correlation between the wavelength and the light energy enters a substantially stable region, and the excitation of electrons from the valence band to the conduction band in the silicon wafer W is limited. Therefore, when the electroless plating process is executed, 500 nm is selected as the lower limit value of the wavelength of the light irradiated by the processing room light 12. Moreover, 780 nm which is the maximum wavelength in the visible light region was selected as the upper limit value of the wavelength.

  Thus, the wavelength of the light irradiated by the processing room light 12 was selected in the range of 500 nm or more and 780 nm or less when the electroless plating process was performed. Note that light having a wavelength of 500 nm is recognized as, for example, a photoresist anti-sensitivity region, and its safety has been proven.

  Next, the illuminance range of the light irradiated during the electroless plating process will be described.

  FIG. 3 is a graph showing the correlation between the illuminance under illumination having a peak value near the wavelength of 500 nm and the height variation width of the electrodes. In FIG. 3, the horizontal axis indicates illuminance (lx), and the vertical axis indicates the height variation width (±%) of the electrode depending on the illuminance.

  As shown in FIG. 3, the height variation width of the electrodes tends to be suppressed as the illuminance of the irradiated light decreases.

  Here, the correlation between the illuminance and the height variation width of the electrode is that when the illuminance is 10 lx or less, the illuminance almost enters the stable region, and the variation width of the formed electrode is ± 2% or less. Therefore, 10 lx is selected as the upper limit value of the illuminance of light emitted from the processing room light 12 when the electroless plating process is performed.

  On the other hand, when the electroless plating process is performed, the lower limit value of the illuminance of the light irradiated by the process chamber light 12 needs to be at least greater than 0 in order to satisfy the condition of visualization of the process chamber 10A.

  In this way, when the electroless plating process is performed, the illuminance of the light irradiated by the processing chamber light 12 is selected in the range of more than 0 lx and 10 lx or less.

  As described above, when the electroless plating process is performed, the wavelength of the light irradiated by the processing chamber light 12 is adjusted to 500 nm or more and 780 nm or less, and the illuminance is set to more than 0 lx and 10 lx or less, thereby generating the photoluminescence on the silicon wafer W. Visualization of the processing chamber 10A can be realized while limiting the generation of power to a predetermined value or less.

  FIG. 4 is a graph showing an example of the control of the wavelength and illuminance of light irradiated by the processing chamber light 12 included in the electroless plating apparatus 1 according to this embodiment. In FIG. 4, the horizontal axis represents wavelength (nm) and the vertical axis represents illuminance (lx). In FIG. 4, a region A indicates a range of light wavelength and illuminance irradiated by the processing chamber light 12 during the electroless plating process, and a region B indicates light of the processing chamber light 12 irradiated during maintenance work. The range of wavelength and illuminance is shown.

  As shown in FIG. 4, in the electroless plating apparatus 1, the processing chamber light 12 is controlled to have a wavelength of 500 nm to 780 nm and an illuminance of more than 0 lx and 10 lx or less during the electroless plating process. Irradiate the light. Thereby, 10 A of process chambers can be visualized, limiting generation | occurrence | production of a photovoltaic power to below a predetermined value at the time of electroless-plating processing execution.

  On the other hand, when the electroless plating process is not executed, such as during maintenance work, the silicon wafer W has not yet been carried into the processing chamber 10A, and it is not necessary to consider the generation of photovoltaic power. For this reason, the processing room light 12 irradiates light having a changed wavelength and illuminance in order to improve the workability of the maintenance work. For example, the workability of the maintenance work can be improved by irradiating light having a relatively high illuminance than when the electroless plating process is performed. Note that the processing room light 12 irradiates, for example, light having a wavelength in a visible light region of 380 nm or more and 780 nm or less and an illuminance of 5 lx or more and 500 lx or less.

(Flow of electroless plating method)
Next, a flow of an electroless plating method using the electroless plating apparatus 1 to form a bump electrode on the Al electrode by an electroless plating process using an Al electrode formed in advance on the silicon wafer W as a nucleus. Will be described. Here, a case will be described in which the processing chamber light 12 is turned on throughout the entire electroless plating process so that the progress of the electroless plating process or the equipment state can be monitored.

  FIG. 5 is a flowchart showing the flow of the electroless plating method according to the present embodiment. As shown in FIG. 5, first, the processing chamber light 12 is turned on to visualize the processing chamber 10A (processing chamber light irradiation step: S1). Alternatively, when the processing chamber light 12 is already lit, the wavelength and illuminance of the light emitted from the processing chamber light 12 are changed to a predetermined range. Specifically, the wavelength and illuminance of the light emitted from the processing chamber light 12 are adjusted to the wavelength and illuminance in the region A shown in FIG. At this time, the light emitted from the front chamber light 13 included in the front chamber 10B is also adjusted to the wavelength and illuminance in the region A shown in FIG.

  Next, the silicon wafer W is accommodated in the holder 31 and left for a while to remove (reduce) or reduce the photovoltaic force (photovoltaic removal step: S2). The silicon wafer W that has not been packaged and is in an exposed state is in a state in which photovoltaic power is generated when it is carried into the processing chamber 10A. Thus, by leaving the silicon wafer W in the holder 31 for a while, the generated photovoltaic force can be removed or reduced.

  Next, the natural oxide film naturally formed on the surface of the Al electrode of the silicon wafer W is removed by acid treatment (oxide film removal step: S3). Specifically, the silicon wafer W is first immersed in a water bath and washed with water, and then repeatedly immersed in a dilute nitric acid bath and a sodium hydroxide bath as appropriate. Then, the oxide film formed on the surface of the Al electrode is removed by immersing again in the water tank and washing with water.

  Next, the silicon wafer W is immersed in a zincate tank and a zincate process (Zn displacement plating) is performed (zincate process step: S4).

  Next, the silicon wafer W is immersed in a Ni bath and subjected to zincate treatment and then subjected to Ni electroless plating (Ni electroless plating treatment step: S5).

  Finally, the silicon wafer W is immersed in an Au bath, and after the Ni electroless plating process, an Au electroless plating process is performed (Au electroless plating process step: S6).

  As a result, the deposited metal of Ni and Au can be generated on the Al electrode as a nucleus, and a metal film having a uniform thickness or height, that is, a bump electrode can be formed.

  Thus, according to the electroless plating method, S2 to S6 are executed under illumination that limits the generation of photovoltaic power to a predetermined value or less. For this reason, it is possible to visually monitor the progress of the electroless plating process or the equipment state. Therefore, even if an equipment trouble occurs during the execution of the electroless plating process, the equipment trouble can be detected and dealt with early.

  Further, when an equipment trouble occurs when the electroless plating process is performed, the processing chamber 10A is visualized, so that the restoration work of the equipment can be performed visually. Thereby, workability | operativity can be improved.

  Further, the front chamber light 13 irradiates light adjusted to the wavelength and illuminance of the region A shown in FIG. 4 in the same manner as the processing chamber light 12, so that the front chamber light 13 is transferred from the front chamber 10B to the processing chamber 10A. Even when the light 13 is incident, the photovoltaic force generated on the silicon wafer W can be limited to a predetermined value or less. Thereby, it can suppress that the electrode formed changes and the electrode quality of the silicon wafer W falls.

  In this case, in order to monitor the progress of the electroless plating process or the operation state of the transfer unit 30 or the like, the process chamber light 12 is turned on throughout the entire electroless plating process. explained. However, the present invention is not limited to this. For example, the processing chamber light irradiation step of turning on the processing chamber light 12 as necessary may be performed when equipment trouble occurs. In this case, since the electroless plating process is performed on the silicon wafer W in a light-shielded state, generation of photovoltaic power in the silicon wafer W can be further limited. Thereby, the height variation of the electrode formed in the silicon wafer W can be suppressed, and the electrode quality can be improved.

(Summary of embodiment)
As described above, according to the present invention, in the electroless plating apparatus 1 that forms an electrode by performing electroless plating on the silicon wafer W in the processing chamber 10A inside the light shielding casing 10, the processing chamber 10A includes the silicon wafer W. It is the structure provided with the process room light 12 which can irradiate the 1st visible light whose photovoltaic power generated at the time of irradiation to a predetermined value or less.

  For this reason, for example, when an equipment trouble occurs when the electroless plating process is performed, a device such as an infrared scope is separately used for equipment restoration work as in the past by turning on the processing room light 12. Alternatively, it is possible to visualize the processing chamber 10A and visually restore the equipment without releasing the light shielding state. For this reason, workability | operativity can be improved.

  Further, the light emitted from the processing chamber light 12 is controlled such that the photovoltaic power generated when the silicon wafer W is irradiated is below a predetermined value. For this reason, even if the processing chamber light 12 is turned on, the height variation of the electrodes formed on the silicon wafer W can be suppressed, so that the electrode quality can be ensured.

  Therefore, according to the present embodiment, it is possible to realize the electroless plating apparatus 1 that achieves both electrode quality and workability of the silicon wafer W.

  In the present embodiment, the case where a light source capable of appropriately changing the wavelength and illuminance of the irradiation light is used as the processing chamber light 12, but the present invention is not limited to this. For example, the processing chamber light 12 may be a light source that emits visible light fixed to a wavelength and illuminance that can limit the photovoltaic power generated when the silicon wafer W is irradiated to a predetermined value or less.

  In the present embodiment, the case where the silicon wafer W is used as the semiconductor wafer has been described, but the present invention is not limited thereto. Other than silicon wafers, for example, silicon carbide (SiC) wafers, gallium arsenide (GaAs) wafers, gallium phosphide (GaP) wafers, gallium nitride (GaN) wafers, and other semiconductors that generate photovoltaic power when exposed to light. A wafer can be used.

  Moreover, in this embodiment, although the partition plate 11 is provided in the inside of the single light shielding housing | casing 10, it divides into the process chamber 10A and the front chamber 10B, However, This invention is not limited to this. For example, the front chamber 10 </ b> B may be formed by connecting a light shielding member different from the light shielding housing 10.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims, and the embodiments can be obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The present invention can be suitably used when an electrode is formed on a silicon wafer by an electroless plating process.

DESCRIPTION OF SYMBOLS 1 Electroless plating processing apparatus 10 Light-shielding housing | casing 10A Processing chamber 10B Front chamber 11 Partition plate 12 Processing chamber light (1st light source)
13 Front room light (second light source)
20 treatment tank 30 transfer unit W silicon wafer (semiconductor wafer)

Claims (9)

In an electroless plating apparatus for forming an electrode by performing an electroless plating process on a semiconductor wafer in a processing chamber inside a light shielding casing,
2. The electroless plating apparatus according to claim 1, wherein the processing chamber includes a first light source capable of irradiating a first visible light whose photovoltaic power generated when irradiating the semiconductor wafer is a predetermined value or less.   2. The electroless plating apparatus according to claim 1, wherein the first visible light has a wavelength of 500 nm or more and 780 nm or less and an illuminance of more than 0 lx and 10 lx or less.   The electroless plating apparatus according to claim 1 or 2, wherein the first light source is capable of adjusting a wavelength and an illuminance.   The electroless plating apparatus according to claim 3, wherein the first light source is capable of irradiating a second visible light having an illuminance higher than that of the first visible light. A front chamber that is maintained in a light-shielded state and allows observation of the inside of the processing chamber,
5. The front chamber includes a second light source capable of irradiating a third visible light whose photovoltaic power generated when irradiating the semiconductor wafer is a predetermined value or less. The electroless plating apparatus according to any one of the above.   6. The electroless plating apparatus according to claim 5, wherein the third visible light has a wavelength of 500 nm or more and 780 nm or less, and an illuminance of more than 0 lx and 10 lx or less.   The electroless plating apparatus according to claim 1, wherein the semiconductor wafer is made of silicon. In an electroless plating method for forming an electrode by performing an electroless plating process on a semiconductor wafer in a processing chamber maintained in a light-shielded state,
An electroless plating method, comprising: an irradiation step of irradiating the semiconductor wafer with visible light having a photoelectromotive force generated upon irradiation of the semiconductor wafer of a predetermined value or less.   The electroless plating method according to claim 8, wherein the visible light has a wavelength of 500 nm or more and 780 nm or less, and an illuminance of more than 0 lx and 10 lx or less.

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