TWI244134B - Device and method for removing metal in etchant, device and method for etching semiconductor substrate, and etchant for semiconductor substrate - Google Patents

Abstract

The present invention provides a method for suppressing metal contamination onto a wafer during etching process and for realizing a long life of etchant by reducing metal in alkali etchant. The etchant is contacted with a metal absorbing member 4. Thereby the metal in the etchant is adsorbed and caught by the metal absorbing member 4.

Description

1244134

[Technical field to which the invention belongs] The present invention relates to a metal removing device for an etching solution that captures metal in an etching solution by contacting a member that becomes an inorganic substance and does not contain a metal to be captured with the remaining liquid phase, and the metal of the etching solution Removal method, etching device for semiconductor substrate, etching method and etching solution for semiconductor substrate, and even an etching solution for reducing metal content. [Previous technology] Semiconductor substrates (wafers) used in IC wafers are formed through a plurality of wafer manufacturing processes, such as the cutting process of single crystal silicon ingots, and the grinding, etching, and polishing processes of cut wafers. In these wafer manufacturing processes, a conventional etching process uses an acidic (hf / hno3) etching solution, and performs acid etching at normal temperature. However, in this acid etching, there are problems in that the etching streaks due to the streaks due to the concentration of the etching solution are easily formed, and the flatness is improved. With the advancement of technology, the conventional acidity of the wafer, which has been required to be south flatness, cannot meet this requirement. In order to meet the requirements of such flatness, alkali etching using an alkali-based etching solution has been performed at present. As the etchant used for alkali etching, KOH, NaOH, LiOH, etc. are considered, but even among them, low-cost NaOH is used. However, the alkali etching system by NaOH is mostly performed at so-called 60 °. (: ~ 90.) In the condition of high temperature and so-called high concentration of 30% to 60% by weight, due to this condition, diffusion contamination of the metal is caused in the wafer substrate '.

7054-6516-PF (N3); Ahddub.ptd Page 5 V. Description of the invention (2) Especially the Cu or Ni-based diffusion coefficient becomes higher, and the metal system that diffuses into the wafer is easy to spread. Matrix. Expected storage, etc., comes out of the wafer surface, = to cause adverse effects. In addition, the nickel series is significantly worse than the second: Sheep '(GOI (Gate Oxide Intogritw)-^ nQT7. Grity (grid rolling friction)), or 0SF (feature 0xidati. n_induced stacking). The source of metal contamination is the etchant contact in the device, the etching environment, the etchant, or the wafer itself. All of these must be cleaned. Hereinafter, the metal contamination of the etchant or the technique for producing the etchant will be described. Fig. 7 is a graph showing the relationship between the metal content in the etching solution and the metal contamination amount in the silicon wafer substrate. Fig. 7 shows the results of Cu and Ni in the sNaOH solution. FIG. 7 shows the results of experiments performed by the inventors. In this experiment, the conditions for alkali etching were: • Si wafer processing time • 200 sec • NaOH concentration: 48 wt% • NaOH temperature: 85 t: ’Metal contamination was intentionally performed on ultra-high purity NaOH. In addition, in the evaluation of the metal as the wafer substrate, metal is deposited on the wafer surface by heating the wafer side. It is known from FIG. 7 that the more ionized metal in the etching solution, the more metal contamination in the wafer substrate. From this result, it can be said that ... In order to reduce 7054-6516-PF (N3); Ahddub.ptd page 6 1244134 V. Description of the invention (3) Low amount of metal in the wafer base. In addition, the metal contained in the alkaline etching of the pollution amount of Cu / N NaOH is the so-called technology that can be said to make money check. Generally, it is used as a chelating agent or the following patents. [Patent] [Inventive content] [How to solve the invention, but >> degree (τ ^ ρΗ value) metal reduction ability by the inventor In addition, the power consumption is suitable for use as a report of metal pollution, therefore, It is necessary to reduce i = 10E9atoms (atomic number) / cm2 or less in the wafer substrate after acid etching in the same amount of the etching solution. In order to achieve this degree of acid etching, it is required to maintain and manage the NaOH solution level 'to about 10 ppt. In this way, it is necessary to reduce the amount of metal in the etching solution from the viewpoint that the amount of metal contamination is equal to that of acid etching. Techniques aimed at reducing the amount of metals in a solution include a chelating resin technique or an electrolytic method. In addition, Document 1 describes that the so-called alkali-based etching solution, the impregnating non-etching solution, the addition of a reducing agent, and the adhesion of metal to stainless steel, Japanese Patent Publication No. 2 0 1-2 5 0 8 0] At the moment, A is recognized as an experiment in the technical trip of reducing the agent or chelating resin significantly at high temperature and high transmission. Function. This is a technique in which the C gas or Krypton 2 gas is etched by alkali in other problems when the electrolysis method is used. . Therefore, the electrolytic method does not

1244134 V. Explanation of the invention (4) In addition, in the composition of iron or nickel, this ’is a kind of contamination by metal contamination with the aforementioned liquid. In general pollution. That is, it can be increased. Therefore, the metal is contaminated, and therefore, there is a problem in exchange operation of the etching etchant. In the present invention, the metal in the etching solution is long and the etching solution is long. In view of such a solid state, the life of the etching process is suppressed. When the patents mentioned above are presented, it is impossible to produce a line of etching solution. The stainless steel of Document 1 contains a so-called branch which is easily dissolved in an etching solution. Because of the fact that the so-called promoting etching is sufficient to reduce the gold of the alkali-based etching solution, the etching solution is gradually contaminated with metal. The amount of time that is used to prevent the etching solution caused by the etching of the wafer is very short. . It is shortened. Therefore, 70% of the deterioration of the etching efficiency is extremely increased, and the cost is increased. By reducing the metal pollution of the alkali-etched wafers, it is also a solution to the problem. [Means to solve the problem] ^ 1 The invention is a device for removing metal mixed with alkali corrosion, and is characterized by a metal engraving solution Π :: a metal member for catching an object, and a metal if the above-mentioned member捕 金属 的 之 # Officials are used as inorganic materials and do not contain the natural genus members of the capture target. In this specification, the metal capture device of TT is a metal attachment device. And the attached components are in contact with the etching liquid. 7054-6516-PF (N3); Ahddub.ptd 1244134 on page 8. V. Description of the invention (5) — = Attached to the metal adsorption member. Like this liquid. The genus is captured on the metal-adsorbed member to produce a clean etch. The component system described above includes the form of the aforementioned member. The second invention is related to the engraved liquid 1 and is characterized by the invention of charcoal. The third invention is characterized in that the first invention is a fiber. The fourth invention 'is characterized in that the surface area of the member is 60 cm2 or more when it is raised at the same time. The 2nd, 3rd, and 4th inventions are capable of effectively forming a metal adsorption member. The form of the fiber is: fiber; or second; month =: the ratio of the fiber and particles filled in the same volume is larger than the surface area of the particles. The surface area of the old fiber is compared to the treatment of the product: metal with a size and money to remove the m, and it is best to make the metal adsorption member into the fiber. Sucking becomes fiber. If it is 60 cm2 or more, the metal and the surface area are considered as adsorption members. As a metal, the fifth invention is a method for removing metal mixed with alkali, which is characterized in that it does not include the metal to be captured. The component = 丨 = is an inorganic substance and the metal is absorbed; The metal in the silver engraving liquid t and the metal attached to the aforementioned member are captured in contact with the liquid phase, and the etching solution after the aforementioned metal capturing treatment is processed. #Release becomes a dilution of a given concentration. The fifth invention is an invention that replaced the first invention as a method. About a page 97054-6516-PF (N3); Ahddub.ptd 1244134 V. Description of the invention (6) ____ is more effective Ways to capture metal. The higher the concentration of the gold engraving solution, the more it absorbs more = the component system has a so-called residual ::. This property is used. Going by etching solution; quality. In the etching solution generation process of the fifth etching solution, the two members are brought into contact with each other to produce a clean J member, and the high-concentration etching is performed. The liquid and metal are adsorbed on the adsorption member. Then, the metal with a high concentration of two is diluted and adsorbed to the gold etchant. The invention of the etching solution to generate a predetermined concentration is an etching treatment device for etching a conductor substrate using a rhyme etching solution. The conductor substrate + + is engraved with a liquid tank. It is made into an inorganic substance and stores the metal of the aforementioned components of the etching solution. The metal in the capture f is adsorbed and captured between the 1st and 2nd communication paths through the second connection and the metal capture part of the == capture part to circulate the liquid ## communication path to the liquid tank and immerse Γ. It is placed in the Mingji Temple, and the tank is used to store the solution. Among them, the second communication path and the gang, the η storage tank and the metal capture section are set between the first and the capture section. Second, in the etching solution tank * metal capture generation ♦ infiltration ^ etch processing of the seventh invention of the etching solution generation process and the wafer etching process to remove metal from the etching solution in the same manner as in the case. The conductor substrate X is a liquid electrolyte and the semiconductor substrate is a half of the semiconductor substrate. The device is characterized in that it includes: a member storing a metal substrate and a metal substrate and an inorganic substrate. And does not include the metal captured in the aforementioned components and the object of capture: metal adsorption in the etching solution and capture is a capture trap, which connects the etching bath and metal capture! 7054-6516-PF (N3); Ahddub.ptd Section 10 Page 1244134 V. Description of the invention (7) The first and second communication paths of the catching department; through the first and second communication paths, the etching bath is etched between the liquid tank and the metal capture section to circulate the etching treasure, and the first etching solution in the first coin. The difference between the second etching bath and the width / south of the bath is different from that in the first etching bath, and the etchant is stored. A second communication path and a pump are provided between the first etching capturing part. Between the first etching solution tank and the metal capturing part, the etching & image, circulated between the first etching solution tank and the metal capturing part, and the metal was removed from the #etching solution to produce a clean etching solution. The etching solution was created by the first etching. The liquid bath starts to be transferred to the second etching liquid, and the second liquid engraving liquid tank 'storage money' is immersed in it, soaking the wafer. ㈢ 样 'performs the wafer engraving process. . The eighth invention is a manufacturing method of a conductor 蚀刻 for etching a semiconductor substrate using an alkali-based etchant. After the metal is adsorbed and captured on the member, the conductive substrate is etched in an etchant. X S t uses a metal adsorption member which becomes an inorganic substance and does not contain a metal to be captured in the eighth month. When the metal adsorption member is brought into contact with the etching liquid phase, the metal system contained in the etching solution is adsorbed on the metal adsorption member. The metal in the etching solution is captured on the metal adsorption member, and a clean etching solution is generated. In this etchant, the wafer is immersed and etched. 9. The ninth invention is an alkali-based etching solution used when etching a semiconductor substrate, and is characterized in that the metal content is reduced by coming into contact with a member that becomes an inorganic substance and does not include a metal that captures an object.

1244134 V. Description of the invention (8) The alkali-based etching solution containing metal is in contact with the metal-caught member; the inorganic substance does not include the metal-captured adsorption member. As a result, the metal in the oblique coin engraving solution is captured to reduce the metal content in the etching solution. [Effects of the Invention] According to the present invention, the metal in the liquid. In this way, the etched member is reduced, and the metal contamination clips of the etched wafer are adsorbed. Depleted metal, therefore, suppresses etched wafers. ,, ^ can provide to reduce metal pollution. In addition, the etchant is kept clean and the life of the etchant. Centroid 'Therefore, the embodiment can be extended] The following is the implementation of the present invention. The embodiment is described with reference to the drawings, and the metal used in the present invention is used in the etching solution and does not include the catching cattle. It becomes an inorganic substance and contains a substance. Specifically, the material is, for example, steel (c) or the like. In the case of such metal parts / metals with 5 W carbide) or liquid ionized metal parts; when the faceted liquid phase contacts, the surname is carved on the surface of the two parts. In addition, the metal adsorption member system does not include a genus. Therefore, in the etching solution, the target gold is used to dissolve the object as a metal adsorption member. The application of ^ ~ 3 series shows the use of w, and it will be described later in "a certain form". Example

Ml Page 12 7054-6516-PF (N3); Ahddub.ptd Ι24Φ134 V. Description of the invention (9) 4, 5 shows the use of C as a certain energy of the metal adsorption member. [Embodiment 1] Fig. 1 (a) is a block diagram of the first embodiment, and Fig. Kb) is a schematic diagram of a SiC filter. In the etching solution tank 1, an alkali-based etching solution is stored. In this embodiment, NaOH solution is used as the alkali-based surname solution. The NaOH solution concentration (% by mass) is 40% to 60% of an alkaline aqueous solution. In order to efficiently perform metal capture by the metal adsorption member, the NaOH solution is preferably 70t = 90C. , The etching liquid tank 1 is connected to one end of the pipeline 2 of the pump 2 set in the middle. The other end of the pipeline 11 is connected to the supply switching section 3. In addition, in the engraved liquid tank 1, the connecting tube 12 is covered with a blanket ^ ^ 1 〇 ^ &; Z 丄. The other end of the official road 12 is connected to the discharge switching section 5. An on-line heater (not shown) is installed in the middle of the pipeline 11 or the pipeline 12. u In the supply switching section 3, the Na0H liquid supply system, that is, the circuit 11 and the HF liquid supply system, that is, the pipeline 21 is connected. The fluid supply side of the SiC filter 4 is also connected. The supply switching unit 3 controls the fluid (Na0H solution, sting solution) supplied to the SiC filter 4 by switching. The switching operation can be performed in accordance with a switching signal from a controller (not shown), and the lamp can also be performed manually. In addition, it may be only time. On the upstream side of the SiC filter 4, the supply switching section 3 is connected, and on the side, the discharge switching section 5 is connected. The SiC filter 4 is shown in FIG. 丨 (b), and is roughly composed of a pillar 41 and Si (: particles) filled in the pillar 41. In this embodiment, the use of Sic particles 42 is possible because Sub-shaped SiC makes the contact area between SiC and NaOH liquid larger, which means that it can be%. Page 13 7054-6651-PF (N3); Ahddub.ptd 1244134

V. Description of the invention (10) The reason for the metal trapping force of the large SiC filter 4. It is thought that in order to increase the contact area with NaOH and to become a small filter, the shape of SiC is made into particles, but Sic can also be made into other shapes. If the siC surface area per 1 liter of Na0H solution becomes 60 cm 2 range / degree, it has the effect of removing metals.

The discharge switching section 5 is connected to the discharge system of NaOH solution, that is, the pipe 12 and the discharge system of HF solution, that is, the pipe 22. In addition, the fluid discharge side of the S1C filter 4 is connected. The discharge switching unit 3 controls the discharge direction of the fluid (NaOII liquid, HF liquid) discharged from the SiC filter 4 by a switching operation. The switching operation can be performed in conjunction with a switching signal from a controller (not shown) or manually. It can also be a valve. The HF liquid supply unit 6 supplies the HF liquid to the SiC filter 4 in order to wash the 3 ^ particles provided in the Sic filter 4. The time for supplying mash is arbitrary, but it must be the time when no liquid is supplied to the Sic filter 4. Next, the operation of the device shown in Fig. 1 will be described. The etching bath 1 is filled with Na0H solution, and the NaOH solution is heated to 70 ° C to 9 ° C (about rc) by an on-line heater (not shown), and the wafer is immersed in the Na0H solution. Etching of the circle.

In the state of generating clean Na0H solution, the supply switching unit 3 is connected to the first channel 11 and the Si C filter 4 and the discharge switching unit 5 is connected to the § 丨 ◦ filter 4 and the NaOH solution when starting pump 2. By the etching bath! Initially, it is supplied to the Sic filter 4 through the pipe 11 and the supply switching section 3. Supply to sic filtering

1244134, Invention Description (11)-"The NaOH solution of Zhai 4 is in contact with the SiC particles 42 filled in the column 41, and at the same time 'flows to the downstream side through the discharge switching section 5 and the pipeline 丨 2 and Discharge to surname carved liquid tank 1. That is, the Na0H liquid system circulates between the etching liquid tank 1 and the SiC filter 4. When the metal iNaOH solution is passed through the Sic filter 4, the metal in the NaOH solution is adsorbed on the Sic particles. Therefore, when the NaOH solution is passed through the liquid to the SiC transition device 4, the amount of metal contained in the NaOH solution is reduced. As a result, a clean etching solution is generated. An etching solution generation process is performed in which a metal is removed by an etching solution to produce a clean etching solution. In addition, the resulting etching solution is immersed in the wafer and subjected to a lasting treatment. The etching solution generation processing system may perform the etching processing all the time, and may also perform the processing other than the etching processing. However, the amount of metal adsorbed on the SiC particles 42 is limited. The S i C particles 42 that adsorb the metal sufficiently reduce the metal trapping force. Therefore, the replacement operation of the Si C filter 4 or the rinse operation of the Si C filter 4 described below must be performed regularly. In the state where the Si C filter 4 is flushed, the supply switching section 3 is connected to the pipe 21 and the Si C filter 4, and the discharge switching section 5 is connected to the Si c filter 4 and the pipe 22. First, the HF liquid is supplied to the SiC transitioner 4 through the pipe 21 and the supply switching section 3 'by the HF liquid supply section 6. The HF liquid supplied to the SiC filter 4 comes into contact with the Si C particles 42 filled in the column 41, and at the same time flows to the downstream side 'and is discharged through the discharge switching section 5 and the pipe 22 to the outside. When the jjF liquid is passed through the Si C filter 4, the metal system adsorbed to the Si C particles 4 2 is dissolved in the η f liquid. Therefore, the SiC particles 42 are in a clean state, and the metal capture is revived.

7054-6516-PF (N3); Ahddub.ptd p. 15 1244134

Force 0 considers that the metal ions have an effect on desorbing the Sic adsorption mechanism. In other words, it is considered that Si is different from electricity ... As mentioned earlier, the ionization in the engraved liquid and its attachment to the solid-liquid interface, that is, the surface of the SiC member. Fig. 2 to Fig. 4 show the results of the experiment by the inventors. Figure 2 is a graph showing the relationship between the flow time of the etching solution to the SiC filter and the adsorption of particles y & π. Figure 2 shows the results for copper and nickel in NaOH solution. In this experiment ’, the liquid-passing conditions for the Sic filter 4 are as follows: • P-Si wafer (IOOg) is impregnated in the coin-cut liquid tank 1 • NaOH concentration: 48wt%

• NaOH temperature: 85 ° C • Total surface area of SiC particles: 250 0cm2 In addition, as the metal evaluation surface of Si C surface, the metal adsorbed on s 丨 c was dissolved in HF liquid, and evaporated to dryness. After diluting the solution, the measurement was performed by icp mass spectrometry (ICPMS). Fig. 3 is a graph showing the relationship between the flow time of the etching solution to the s? C filter and the metal concentration in the etching solution. In Fig. 3, the results of copper and nickel in KNaOH solution are shown. In this experiment ’, the conditions for the liquid flow of the si C filter 4 are as follows:

7054-6516-PF (N3); Ahddub.ptd Page 16 1244134 V. Description of the invention (13) • P-Si wafer (100g) immersed in # 刻 液槽 1 • NaOH? Agronomy: 48wt% • ^ 011 temperature: 85. 〇 • The total surface area of SiC particles: outside 250 0cm2 In addition, the metal contamination of the ultra-high-purity Na0H solution is intentional. The metal evaluation as a wafer substrate is to deposit metal on the wafer surface by heating one side of the wafer. Fig. 4 is a graph showing the relationship between the flow time of the etchant to the s? C filter and the metal concentration of the wafer substrate. In Figure 4, the results are shown for steel and nickel in NaOH solution. In this experiment, the alkali etching conditions were made as follows. • Si wafer processing time ... 200sec • NaOH concentration: 48wt%

• NaOH temperature: 85 ° C In addition, the evaluation of the metal in NaOH is to measure the metal adsorbed on the chelate resin by ICP mass spectrometry (ICPMS). As shown in Fig. 2, the longer the liquid passing time of the NaOH solution to the SiC filter 4 becomes, the higher the metal concentration on the JSiC particles 4 becomes. From this result, the time during which the NaOH liquid circulates between the etching liquid tank 1 and the SiC filter 4 is obtained. The metal system in the NaOH liquid gradually adsorbs and captures the SiC particles 42. The results shown in Figs. 3 and 4 were obtained. As shown in FIG. 3, the more the liquid passing time of the NaOH solution to the SiC filter 4, the lower the metal concentration in the NaOH solution becomes. In addition, as shown in Fig. 4, the longer the liquid passing time of the NaOH solution to the SiC filter 4, the longer the wafer substrate.

7054-6516-PF (N3); Ahddub.ptd Page 17 1244134 V. Description of the invention (14) The lower the metal concentration becomes, if the first embodiment is adopted, the Sic member will adsorb the metal in the etching solution . The metal in the etchant is reduced like this, so the metal contamination of the wafer processed by etching is suppressed. Therefore, it is possible to provide wafers with reduced gold and j. Therefore, it is possible to extend the life of the etching solution while keeping the etching solution clean. In addition, according to the first embodiment, since the si c filter is washed, the life of the etching solution can be prolonged more than that without washing the si c filter. In addition, S i C is resistant to any kind of acid and acid. Therefore, it is possible to perform the aforementioned alkali-based etching solution generation and flushing by HF solution. In addition, since the etching solution generation apparatus and the etching process are performed as a single apparatus, the system is miniaturized. [Embodiment 2] Fig. 5 is a block diagram of a second embodiment. This embodiment is different from the first embodiment in that the generation of clean NaOH solution and the flushing of the Si C filter 4 are performed by separate devices. Therefore, the SiC filter 4 is freely attachable and detachable to and from the circulation line of NaOH solution and the supply and discharge line of HF solution. If such a device is used, the production of clean NaOH solution is performed by the manufacturing line of etching liquid tank 1, pipeline 丨 丨, Sic filter 4 and pipeline 12, and the flushing system of sic transition device 4. With the external HF supply section 6, pipeline 21, SiC filter 4, and pipeline 22,

7054-6516-PF (N3); Ahddub.ptd Page 18 1244134 V. Production line of invention description (15). Similar to the first embodiment, the #etching liquid generation processing system can always perform the money engraving process, and can also perform the process other than the silver engraving process. According to the second embodiment, the same effect as that of the first embodiment can be obtained. In addition, the circulation line of the NaOH solution becomes simple. [Embodiment 3] Fig. 6 is a block diagram of a third embodiment.

In this embodiment, a NaOH solution is stored in the etching solution tank 1, and the SiC filter 4 is immersed in the NaOH solution. Since the metal in the NaOH solution is adsorbed on the SiC particles in the Sic filter and the device 4, the metal concentration of the NaOH solution is reduced. In addition, as in the second embodiment, the si c filter 4 can be rinsed by a device provided for each individual. Similarly to the first embodiment, the etching solution generation treatment system may be continuously subjected to the etching treatment, or may be performed in addition to the etching treatment. According to the third embodiment, metal contamination of the etched crystal is suppressed. In addition, the entire system becomes very simple. [Example 4] The comparison is made with Sic for C of a metal adsorption member. The drawing 8 shows the results of experiments performed by the present inventors. Fig. 8 is a graph showing the relationship between the flow time and time of the etchant. In Fig. 8, the results of filling the metal with particles and the NaOH solution of the lye are shown. At the same time, the filter of the C particles is shown to pass through the filter. Page 197054-6516-PF (N3); Ahddub. ptd 1244134 V. Description of the invention (16) The results of NaOH solution, and the results of copper and nickel in NaOH solution are shown. In this experiment, the liquid passing conditions of the Si C filter and the C filter were as follows. • Immersion of P-Si wafer (100g) in etching bath 1 • NaOH concentration: 48wt%

• NaOH temperature: 85 ° C • Total surface area of particles: 2 500 cm2 In addition, as the metal evaluation of Si C surface and C surface, the metals adsorbed on SiC and C are dissolved in HF liquid, evaporated to dryness. After dilution with an acid solution, measurement was performed by ICP mass spectrometry (ICPMS). As shown in Fig. 8, the adsorption amounts of copper and nickel relative to SiC and the adsorption amounts of copper and nickel relative to C are almost the same. From this result, it can be said that Sic and C are the same in terms of metal capture force. The C system is better than Sic in the following aspects. The c-system can be in various forms, and therefore can be made into particles & In comparison of the fibers filled in a volume and Table 2 are larger than the surface area of the particles. That is to say, in the state of filling with: Ν and particles and passing through the NaOH solution, the fiber and area are larger than the contact surface between the particles and the liquid: the fiber is more than the filler. The converter is even more :: Fill in [Solution :: 5] Generally C series is cheaper than SiC, so reduce the cost. Page 20 7054-6651-PF (N3); Ahddub.ptd 1244134 V. Description of the invention As shown in FIG. 9, the metal adsorption member has a property that the higher the concentration of the etching solution, the more metal is adsorbed. Here, a description will be given of an embodiment in which an etching solution generation process is efficiently performed using this property. FIG. 9 shows the results of experiments performed by the present inventors. Fig. 9 is a graph showing the relationship between the concentration of the etchant and the amount of metal adsorbed on the c particles. In Fig. 9, the results are shown for copper and nickel in NaOH solution. In this experiment, c-particles were impregnated in NaOH solution stored in an etching bath so that the conditions were as follows. • P-Si wafer immersed in a money-cutting liquid bath (100g)

NaOH? 30 ° ~ 60% by weight • Metal ion concentration in Na0H solution: Ni = 20ppb, Cu = 10ppb • NaOH temperature: 85 • Full surface area of C particles · 2500cm2 • C particle immersion time: 2 hours In addition, as the metal evaluation of the surface of C particles, the metal adsorbed on c was dissolved in HF liquid, evaporated to dryness, and diluted with an acid liquid, and then performed by 1CP mass spectrometry (ICPMS). Determination. Tian knows from Figure 9 that the higher the concentration of NaOH solution, the more it is adsorbed on the c particles, and the more it is in the nickel. It was also found that the increase in the concentration of NaOH solution is greater. Therefore, after the high-concentration NaOH solution is brought into contact with C and the metal in the NaOH solution is adsorbed on c, if the NaOH solution is diluted to a concentration required for the etching process, an etching with a reduced metal content can be generated. liquid.

7054-6516-PF (N3); Ahddub.ptd Page 21 1244134 V. Description of the invention (18) Figure 10 is a block diagram of the fifth embodiment. This apparatus is composed of an etchant generation processing section 50 and an etching processing section 6G. The coin carving solution generation processing unit 50 is connected to the etching liquid tank 5 j, the pump 5 2, the C filter 5 3 and the on-line heater 5 4 through the pipeline, and the coin carving processing unit 60 is connected to the pipeline through the pipeline. The etching solution tank 61, the pump 62 and the online heater 64 are connected. In the etching solution tank 51, a high-concentration test system etching solution is stored. In this embodiment, NaOH solution is used as an alkali-based etchant. In the etching solution tank 5 j,, one end of the pipeline 56 of the pump 52 is set in the middle. The other line 56 is connected upstream of the C filter 53. In addition, in the etching solution tank 5 j,, one end of the pipe 57 is connected. The other end of the pipe 57 is connected to the downstream side of the in-line heater 54. The downstream side of the C filter 53 and the upstream side of the in-line heater 54 are communicated through a pipe 58. C filter 5 3 is filled with C fiber. In addition, you can subtract 53 from c to fill c in other forms, or fill Sic. It seems that the etching solution generated by the etching solution generation processing unit 50 is stored in the coin etching liquid tank 61 '. In the etching solution tank 61, one end of a pipeline 66 provided with a pump 62 in the middle is connected. The other end of the pipeline 66 is connected to the upstream side of the in-line heater. In addition, one end of the pipeline 67 is connected to the etching bath 61. The other ends of the pipeline 66 are connected to the downstream of the in-line heater 64 Next, the operation of the device shown in FIG. 10 will be described. In a high-concentration "0.11" solution stored in the etching bath 51, Si is added in advance as a reducing agent. When the pump 52 is started, the high-concentration rhenium starts from the etchant and is supplied to the c filter 53 through the line 56. The high-concentration Na0H liquid supplied to the c filter 53 comes into contact with the c fiber, and flows downstream 1244134

The side 'is heated to 40 ° C or higher by the on-line heater 54, and preferably discharged through the pipe 57 to the engraved liquid tank 51 to a degree of 80 °. That is, a high-concentration NaOH solution is circulated between the etching bath 5 and the filter 53. When the high-concentration NaOH solution containing metal is passed to the C filter 53, the metal in the high-concentration NaOH solution is adsorbed on the C fiber. Therefore, when the high-concentration NaOH solution is passed to the c filter 53, the amount of metal contained in the high-concentration "0 [1 solution is reduced. When the predetermined time elapses, the pump 52 is stopped. The liquid is transferred from the etching solution tank 51 to the etching solution tank 61. The high-concentration palpitate solution stored in the etching solution tank 61 is diluted with pure water to generate a NaOH solution of a predetermined concentration. In the etching solution tank 61 The NaOH solution was used to immerse the wafer. Therefore, when the wafer 62 was started, the NaOH solution was started from the etching solution tank 61 and supplied to the on-line heater through the pipeline 66. Supply to The NaOH liquid system of the on-line heater 64 is heated to a temperature of 60 ° C to 90 ° C, and is discharged to the etching liquid tank 61 through the pipe 67. In this way, the Na0H liquid system is maintained at a set temperature and is etched. Similarly to the first embodiment, the etching solution generation process and the etching process can be performed only by the etching solution generation process unit 50 in FIG. 10. In addition, the c filter can be provided in the circulation system of the etching process unit 60. In addition, as in the first and second embodiments, the structure of the c filter 53 can be washed. — If the fifth embodiment is adopted, the same effect as that of the first to fourth = application forms can be obtained. In addition, the present embodiment makes the etching solution generation process more effective than the first through fourth application forms. The efficiency becomes more favorable, so that the etching solution generation process can be shortened.

1244134 V. Description of the invention (20) In addition, because the generation of the etching solution and the etching process are ordered by different placements, even the system on the generation side of the etching solution = obstacle can be carried out. Etching. As soon as Tyson P is here, it will show the effectiveness of the foregoing embodiments. Silicon wafers that have passed each wafer manufacturing process are evaluated and incorporated into the product. For the etching process performed in each embodiment, an evaluation method is used in which the precipitation is measured on a wafer surface heated at 100 t for 30 minutes. As a result, the amount of Cu · Ni was 1E10 atoms / cm2 or less. If the amount of Ni is at this level, it can be said that the metal content is reduced, and it can be said to be a good product. In addition, in the manufacturing process of components such as 1C wafers, in order to remove the coating on the wafer surface, 'An etching process is performed, but the present invention is applicable to this etching process. 7054-6516-PF (N3); Ahddub.ptd Page 24 T244Π4 ____ Brief description of the diagram [Simplified illustration of the diagram] Figure 1 (a) is a block diagram of the first embodiment, and Figure 1 (b) is a SiC filter No intention. Fig. 2 is a graph showing the relationship between the flow time of the etchant to the SiC filter and the amount of metal adsorbed on the Sic particles. Fig. 3 is a graph showing the relationship between the flow time of the etching solution to the Si C filter and the metal concentration in the etching solution. Fig. 4 is a graph showing the relationship between the flow time of #etching liquid to the Si C filter and the metal concentration of the volume. M ^ FIG. 5 is a block diagram of the second embodiment. Fig. 6 is a block diagram of the third embodiment. Fig. 7 is a graph showing the relationship between the metal content in the etchant and the silicon wafer substrate. Fig. 8 is a graph showing the relationship between the flow time of the etchant and the metal on the particles. Amount of genus adsorption Figure 9 is a graph showing the relationship between the concentration of # 刻 液 and the genus of c particles. Fig. 10 is a block diagram of the fifth embodiment. 2 ~ pump; 4 ~ SiC filter; 6 ~ HF liquid supply unit; 1 ~ 2 ~ pipeline; [Description of main component symbols] 1 ~ button carved liquid tank; 3 ~ supply switching unit; 5 ~ pull-out switching unit ; 11 ~ pipeline;

1244134 Simple illustration

21--Pipeline 9 21, '~ Pipeline; 22 -'Pipeline 9 22' '~ Pipeline; 41 -'Pillar 9 42 ~ SiC particles; 50-etch solution generation processing unit; 51-button etch solution Trough; 52 ~ pusam, 53 ~ C filter, filter; 54--online heating benefits, 56 ~ pipeline; 57 ~ pipeline 9 58 ~ pipeline; 60,-famous insect carved processing section; 61 ~ money carved Liquid tank; 62 ~ pump 9 64 ~ on-line heater; 66 ~ pipe; 67 ~ pipe. 7054-6516-PF (N3); Ahddub.ptd Page 26

Claims (1)

Charm 931? 7ί ^ 9 VI. Patent application scope · A metal liquid of the remaining liquid, which belongs to the removal device 'removing the mixed into the test system's engraving, is characterized by: including making inorganic, metal, and etching liquid Contact will etch: two: a metal capture device containing a structural member that captures the metal of the object. Α Α metal adsorption and capture in the foregoing 2 · As in the patent application 圚, where the aforementioned component is a metal removal device containing carbon / etching solution, 3. As in the patent application 圜 where the form of the aforementioned component is fiber. The metal removing device of the insect-etching liquid, as in the first of the scope of the patent application, which is 60 cm2 or more with respect to the 1-liter metal removing device of the etching solution. A liter makes the surface area of the aforementioned components 5 · A metal of a truncated liquid to remove the metal of the liquid, "/ remove mixed into the alkali-based etching, which is characterized by: 饨 利 f is an inorganic substance and does not contain metal to capture the phenomenon I: catch and catch:] '= solution " metal adsorption and capture in the aforementioned component engraving solution, diluted to a predetermined concentration to dilute the etching after the aforementioned metal capture process. 6 · more than a semiconductor substrate The engraving processing device uses a test system | worm array to etch a semiconductor substrate, and / is characterized by including: 7054-6516-PFl (N3) .ptc -~ Tiger 93] coffee / 19 patent application scope ^ ~ amended etching bath, storage metal capture unit: 夜 night; = affiliated components and etching solution ::: inorganic matter and does not include capture objects to capture in the aforementioned components; The first and second communication paths are adsorbed and captured by the metal in the etching solution, and the pump is connected to the first and second communication channels through the first and second communication :: and the metal capture part; m, while etching semiconductor substrates in etching baths and metal capture 7 semiconductor substrates, d processing equipment, using an alkali-based etching solution, which is characterized by: Ϊ1 / etching solution tank 'stores silver etching solution; metal components and Xun Zhao, Guang 4, became an inorganic substance and did not include the capture object. The metal in the last name engraving solution was adsorbed and trapped in the contact with the aforementioned ΓΓ. The first embroidery 2 $ 'connects the first etching solution tank and the metal capture part; capture Circulation between departments = way, the first liquid tank and the remaining metal column engraved in the main liquid tank 'store the remaining metal removal liquid transferred from the first liquid tank to the second liquid tank: stain the semiconductor substrate, and then perform the process. A method for manufacturing a semiconductor substrate made of engraved semiconductors is characterized by the use of a test system etch solution, and is characterized in that the components in the etching solution are contacted with the liquid phase when the components that are inorganic and do not contain the metal to be captured are adsorbed and Capture 7054-6516-PFl (N3) .ptc Page 28 1244134 Case No. 93127642 Amendment VI. After applying for a patent application, the semiconductor substrate is immersed in an etchant and etched HBI 7054-6516-PFl (N3) .ptc No. Page 29