JP2008071799A - Method and apparatus of cleaning semiconductor substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning method and a cleaning apparatus by which the property of a chemical is changed depending on contamination or the like and the chemical capability of the chemical is sufficiently brought out and which are suitable for single wafer treatment. <P>SOLUTION: In the cleaning method, a base liquid B for cleaning is prepared, and supplied to a semiconductor substrate, and then a first chemical P1 is added to the base liquid B at first timing (t1). A first cleaning liquid that the base liquid B is added with the first chemical P1 is supplied to the semiconductor substrate, and the addition of the first chemical P1 to the base liquid B is stopped at second timing (t2). A second chemical P2 is added to the base liquid B at third timing (t3), and a second cleaning liquid that the base liquid B is added with the second chemical P2, and then the addition of the second chemical P2 to the base liquid B is stopped at fourth timing (t4). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for cleaning a semiconductor substrate, and more particularly to a single wafer spin cleaning technique for cleaning an etching residue or ashing residue after dry etching or ashing of a metal wiring material or an interlayer insulating film formed on the semiconductor substrate.

  When processing such as oxidation, diffusion, film formation, lithography, etching, ion implantation, and resist stripping is performed on a semiconductor silicon substrate, a cleaning process for cleaning the substrate surface is performed. Wet cleaning of silicon substrates is roughly classified into a batch type and a single wafer type, but the batch type is excellent in throughput, but has a drawback that the occupied area becomes large due to the large diameter of the substrate. On the other hand, the single wafer processing system processes substrates in units of one sheet, has the advantage that the occupied area can be reduced, and even a large-diameter substrate can be uniformly cleaned in the surface. is there. In spin cleaning represented by a single wafer type, a substrate is rotated while being held horizontally, and a chemical solution or pure water is supplied thereto from a cleaning nozzle to clean the surface of the substrate.

  A typical wet cleaning process includes a first step of removing particles from a silicon substrate, a second step of removing unnecessary natural oxide film on the silicon surface, and a third step of removing heavy metals adhering to the silicon substrate. Each is subjected to the desired chemical cleaning. The first step uses an alkaline mixed solution (SC-1) composed of ammonia water, hydrogen peroxide water and ultrapure water, and the second step uses hydrofluoric acid diluted with ultrapure water (hereinafter referred to as dilute hydrofluoric acid). In the third step, RCA cleaning using an acidic mixed solution (SC-2) composed of hydrochloric acid, hydrogen peroxide solution, and ultrapure water is generally performed. Further, a rinsing process with ultrapure water is performed between these steps. Finally, complete drying is performed in the drying unit.

In the manufacture of semiconductor devices, FEOL (Front End Of Line: transistor formation process centering on a gate process) is mainly about etching of silicon (Si) or silicon oxide film (SiO ₂ ), and silicon or silicon oxide film Is etched with hydrofluoric acid or phosphoric acid, and RCA cleaning is generally used.

  BEOL (Back End Of Line) includes a wiring layer forming process, an insulating layer or interlayer insulating film forming process, a contact forming process, and the like. In addition to Al, Cu wiring by a damascene process is implemented as a metal wiring material, and Ti and TiN are used as barrier metals for Cu wiring. Al, Cu, Ti, and their oxides can be cleaned with various acid and aqueous alkali solutions.

  On the other hand, the residue after dry etching is complicated, and the residue after metal etching is completely different from the residue after etching the interlayer insulating film. Further, the residue is different between the upper and lower portions of the metal wiring or the upper and lower portions of the via hole. For this reason, liquid mixtures that can handle different residues have been used for cleaning.

  For example, Patent Document 1 discloses a cleaning method for completely removing a deposited polymer generated after dry etching, thereby obtaining a highly reliable metal wiring. Further, Patent Document 2 uses HF having an etching rate of 3 nm or more per minute as the first cleaning liquid or an alkaline liquid, and uses a cleaning liquid having a high effect of suppressing contamination reattachment as the second cleaning liquid. A technique for effectively removing contamination is disclosed.

JP 2006-80263 A JP 2000-315670 A

  With a mixed solution (one solution) that mixes multiple chemicals as in the past, we aim to eliminate miscellaneous contamination, protect various materials (inhibition of corrosion), and ensure the stability of storage during transportation and storage The chemical ability of each component cannot be fully exploited. For example, as shown in FIG. 17, in order to remove miscellaneous contamination, the mixed solution is mixed with an oxidizing agent, a reducing agent, a metal solubilizer, and an organic matter solubilizer. In order to suppress, an oxidizing agent stabilizer, a reducing agent stabilizer, and a metal anticorrosive that counteract these functions are mixed.

  Therefore, in order to extract the chemical ability of each component, it is necessary to increase the concentration of the chemical solution to be added, to increase the processing time for cleaning, or to increase the cleaning temperature. However, such a requirement is not suitable for the single wafer cleaning process, and it becomes difficult to process in the factory by using a high concentration chemical solution, which requires separate industrial waste treatment, and waste liquid treatment is expensive. turn into.

For example, cleaning of etching residues or ashing residues after dry etching or ashing of metal wiring materials or interlayer insulating films has the following problems.
(1) Most of conventional chemical solutions require heating at 50 to 80 degrees or require long-time treatment for 5 to 40 minutes, and are not suitable for single-wafer cleaning for low-temperature and short-time treatment. .
(2) Many conventional chemical solutions contain high concentrations of chemical components, particularly high concentrations of organic solvents, and therefore cannot be treated in the factory and are treated as industrial waste. Some recent chemical solutions do not contain an organic solvent and can be processed in the factory. However, such chemical solutions have a low residue removal capability and an insufficient cleaning capability.
(3) In many cases, different chemical solutions are used in the processing after the dry etching of the metal wiring material and the processing after the dry etching of the interlayer insulating film, and the management of the chemical solution and the chemical substance is complicated. For example, a fluorine chemical solution is used for the metal wiring material, and a hydroxylamine chemical solution is used for the interlayer insulating film.
(4) In the case of single wafer cleaning, since the chemical solution is dropped (sprayed) on the rotating wafer in the air, the chemical composition and performance are likely to change due to evaporation, absorption of carbon dioxide gas, and the like. For this reason, although the chemical solution is disposable, the cost of waste liquid treatment increases.
(5) When the quality of the residue changes due to dry etching conditions change, etc., it is necessary to change or adjust the chemical solution each time, and every time the chemical solution is changed, internal registration and certification work of the chemical solution and components are required. Furthermore, it is necessary to confirm the safety of the waste liquid and the treatment method, which takes a lot of trouble for the user and manufacturer of the chemical liquid.

The present invention has been made with such conventional problems in mind, and changes the properties of the chemical solution in accordance with contamination, etc., fully draws out the chemical ability of the chemical solution, and is suitable for single wafer cleaning. It is an object to provide a method and a cleaning device.
It is another object of the present invention to provide a cleaning method and a cleaning apparatus that can flexibly cope with various semiconductor process steps, reduce the burden of waste liquid treatment, and consider the global environment.

  The present invention proposes a system that can make effective use of chemical reactions, shortening the cleaning time, lowering the cleaning temperature, dealing with various pollutants generated by changing etching conditions, and reducing the amount of chemicals used. In order to reduce the processing load of the waste liquid, cleaning is performed while changing the properties of the chemical solution, thereby solving many problems of the conventional chemical solution at a time.

  The cleaning method according to the present invention cleans the semiconductor substrate using a cleaning liquid and includes the following steps. A base liquid for cleaning is prepared, the base liquid is supplied onto the semiconductor substrate, the first chemical liquid is added to the base liquid at a first timing, and the first cleaning liquid is added to the base liquid. Is supplied onto the semiconductor substrate, the addition of the first chemical liquid to the base liquid is stopped at the second timing, the second chemical liquid is added to the base liquid at the third timing, and the second chemical liquid is added to the base liquid. The second cleaning liquid to which is added is supplied onto the semiconductor substrate, and the addition of the second chemical liquid to the base liquid is stopped at the fourth timing.

  In the present invention, a base solution is used as a base solution, and chemical liquids having different components are added to or mixed with the base solution at selected timings to sequentially generate cleaning liquids having different properties, and the semiconductor substrate is cleaned using this. For this reason, since it is not necessary to use a mixed liquid in which a plurality of chemical liquids that counteract the components of the chemical liquid are mixed as in the prior art, the chemical ability can be sufficiently extracted only by adding a low concentration chemical liquid. . This leads to a reduction in the burden of waste liquid treatment. In addition, by changing the chemical solution added to the base solution sequentially, in other words, by changing the components of the cleaning solution, it is possible to flexibly and easily provide the cleaning solution according to the semiconductor process.

  Furthermore, in the present invention, when cleaning the semiconductor substrate, a chemical solution is added to the base solution to generate the cleaning solution, and this is immediately supplied onto the semiconductor substrate. Receiving is suppressed. If the cleaning liquid mixed with the chemical solution is stored or preserved as in the past, it is not rare that the cleaning liquid is altered when actually used. For this reason, it becomes possible to reduce the density | concentration of the chemical | medical solution which should be added.

  The cleaning method of the present invention may use a plurality of chemical solutions in addition to the first and second chemical solutions. Preferably, the third chemical liquid is added to the base liquid at the fifth timing, the third cleaning liquid in which the third chemical liquid is added to the base liquid is supplied onto the semiconductor substrate, and the third chemical liquid is supplied at the sixth timing. The addition of the chemical liquid to the base liquid is stopped, and the cleaning method further includes adding the fourth chemical liquid to the base liquid at the seventh timing, and adding the fourth cleaning liquid in which the fourth chemical liquid is added to the base liquid to the semiconductor substrate. It is possible to stop the addition of the fourth chemical liquid to the base liquid at the eighth timing.

The base solution is preferably a medium having high solubility in the chemical solution to be added, and more specifically, water is the main component. Alternatively, the water used for the base liquid is preferably water with a dissolved gas concentration controlled. Specifically, water degassed dissolved gas, or a single or multiple gases selected from carbon dioxide, nitrogen, oxygen, helium, neon, argon at a constant concentration below the saturation concentration at atmospheric pressure. Dissolved water.
Further, the first, second, third or fourth chemical liquid is supplied in an amount of 1/10 to 1/1000 with respect to the base liquid. If the supply amount of the chemical liquid is reduced, the burden of waste liquid treatment can be reduced accordingly.

  Preferably, the first, second, third, or fourth chemical liquid is a liquid containing an acid as a main component, a liquid containing an alkali as a main component, a solution containing an oxidizing substance as a main ingredient, or a reducing substance as a main ingredient. One of the liquids. The acid-based liquid is an aqueous solution containing any one of sulfuric acid, hydrochloric acid, hydrofluoric acid, nitric acid, or phosphoric acid, and the alkali-based liquid is ammonia, tetramethylammonium hydroxide, or hydroxylated. An aqueous solution containing any one of potassium, a liquid containing an oxidizing substance as a main component is an aqueous solution containing hydrogen peroxide, and a liquid containing a reducing substance as a main component is hydroxylamine, hydrazine, and these An aqueous solution containing any of the salts.

  The single wafer cleaning apparatus for cleaning a semiconductor substrate with a cleaning liquid according to the present invention stores a holding means for rotatably holding the semiconductor substrate, a supply means for supplying the cleaning liquid onto the semiconductor substrate, and a base liquid for cleaning. Base liquid storage means, first chemical liquid storage means for storing the first chemical liquid added to the base liquid, second chemical liquid storage means for storing the second chemical liquid added to the base liquid, The first chemical liquid is added to the base liquid to generate a first cleaning liquid, or the second chemical liquid is added to the base liquid to generate a second cleaning liquid, and the first or second cleaning liquid is supplied from the supply unit. Cleaning liquid control means for supplying the semiconductor substrate onto the semiconductor substrate.

  Preferably, the cleaning liquid control means controls the timing at which the chemical liquid should be added and the amount of the chemical liquid added to the base liquid. The cleaning apparatus further includes a storage unit that stores a plurality of cleaning recipes, and a selection unit that selects a predetermined cleaning recipe from the plurality of cleaning recipes, and the cleaning liquid control unit is configured to select the first or the first according to the selected cleaning recipe. Two cleaning liquids can be produced.

  According to the cleaning method of the present invention, the cleaning liquid of the different components is generated by adding the chemical liquids of the different components to the base solution for cleaning, and the semiconductor substrate is cleaned using the cleaning liquid. Such effects can be obtained.

(1) The chemical composition is mixed based on the base liquid to produce various cleaning liquids, whereby the composition of the cleaning liquid can be simplified and the ability of each chemical substance can be fully derived. For example, the thinner the acid or alkali, the more separated.
(2) By optimizing the composition of the cleaning solution only during the cleaning process, a stable chemical substance can be made highly active only during the cleaning. For example, by changing the liquidity from neutral to alkaline, the oxidizing agent and reducing agent become highly active.
(3) By finely controlling the high activity by time and concentration, it is possible to balance the cleaning ability and corrosion inhibition.
(4) Since many recipes can be assembled by changing the addition flow rate and addition time of the chemical solution, it is possible to cope with various types of contamination. For example, it is possible to cope with contamination deposited in layers with an optimum composition for each layer.

  The best mode of the cleaning method according to the present invention will be described below. In the cleaning method of the present invention, a base solution for cleaning is prepared, and under time control, different chemical solutions are sequentially added to the base solution, and the semiconductor substrate is cleaned with such a cleaning solution while changing the components of the cleaning solution. . Such cleaning is performed by a single wafer spin apparatus.

  FIG. 1 is a diagram showing the concept of the cleaning method of the present invention in an easy-to-understand manner. The vertical axis represents the component, and the horizontal axis represents the processing time. According to the specifications of the single wafer spin cleaning apparatus, the cleaning liquid processing time is preferably 2 minutes or less per wafer, and the processing temperature is room temperature (40 ° C. or less). After mounting the semiconductor substrate, a cleaning base solution is supplied to the substrate at times t0 to t1. The liquid volume is 100 milliliters / minute to 2 liters / minute. The base liquid is preferably 99.5% or more water and contains a fluorine compound.

  As shown in FIG. 1A, at time t1, the first chemical liquid P1 is added to the base liquid B, and the first cleaning liquid in which the first chemical liquid P1 is added to the base liquid B is on the substrate. To be supplied. The addition of the first chemical P1 is stopped at time t2. Therefore, the substrate is cleaned by the first cleaning liquid in which the first chemical liquid P1 is added to the base liquid B during the time t1-t2.

  At time t2, the addition of the first chemical liquid P1 is completed, and at the same time t3 as time t2, another second chemical liquid P2 is added to the base liquid B. When the second chemical liquid P2 reaches time t4, its addition is terminated. Accordingly, the substrate is cleaned by the second cleaning liquid in which the second chemical liquid P2 is added to the base liquid B during the time t3-t4. During the time t4 to t5, the base liquid B is supplied to the substrate.

  In the cleaning of FIG. 1A, the stop time t2 of the addition of the first chemical liquid P1 and the start time t3 of the addition of the second chemical liquid P2 are performed at the same time, but as shown in FIG. In addition, the addition of the second chemical liquid P2 may be started at a time t3 when a predetermined time has elapsed from the stop time t2 of the addition of the first chemical liquid P1. In this case, the base liquid B is supplied onto the substrate between time t2 and time t3.

  You may make it perform the start time t3 of addition of the 2nd chemical | medical solution P2 before the stop time t2 of addition of the 1st chemical | medical solution P1. For example, as illustrated in FIG. 1C, during the time t3-t2, the chemical liquids P1 and P2 are added to the base liquid B to become the third cleaning liquid.

  The ratio of the first and second chemical liquids added to the base liquid B can be changed as appropriate. As shown in FIG. 1D, for example, the amount to which the first chemical liquid P1 is added can be made larger than the amount to which the second chemical liquid P2 is added. Conversely, the amount of the chemical solution P2 may be increased.

  Further, the first chemical liquid P1 and the second chemical liquid P2 may be added to the base liquid B at the same time. For example, as shown in FIG. 2A, the chemical liquids P1 and P2 are added to the base liquid B during the time t1-t2.

Further, while supplying one chemical solution to the base solution B, the other chemical solution may be intermittently added. For example, as shown in FIG. 2B, the chemical liquid P1 is continuously supplied during the time t1-t2, and further, the chemical liquid P2 is intermittently supplied at the time t3-t4. The interval between times t3 and t4 may be varied, for example, the interval may be decreased toward time t2, and the supply amount may be gradually decreased.
It is also possible to add the chemical solution P2 only for a predetermined time during the supply of the chemical solution P1, without intermittently supplying the chemical solution P2. As shown in FIG. 2 (c), the chemical solution P1 is added during the time t1-t2, the addition of the chemical solution P2 is started at the time t3 later than the time t1, and the chemical solution P2 is added at the time t4 faster than the time t2. Stop.

  Further, the chemical liquid P1 and the chemical liquid P2 may be added to the base liquid B alternately. For example, as shown in FIG. 2D, the chemical solution P1 is added at time t1-t2, the chemical solution P2 is added at time t3-t4, and this is repeated for a certain cycle.

  Further, as shown in FIG. 3 (a), the time t1 at which the first chemical liquid P1 is supplied and the time t3 at which the second chemical liquid P2 is added are made simultaneously, and the time t4 at which the addition of the second chemical liquid P2 is stopped. You may make it quicker than the time t2 which stops addition of the 1st chemical | medical solution P1. Alternatively, as shown in FIG. 3B, the time t3 at which the second chemical liquid P2 is added is delayed from the time t1 at which the first chemical liquid P1 is added, so that the first chemical liquid P1 and the second chemical liquid P2 Times t2 and t4 at which the addition is stopped may be simultaneously performed.

  Further, if cleaning with a third chemical solution, a fourth chemical solution, or the like is necessary, the third chemical solution and the fourth chemical solution are added to the base solution B in the same manner as described above, and the properties of the cleaning solution are sequentially set. Can be changed. At this time, the first and second chemical liquid addition sequences shown in FIGS. 1 to 3 can be applied to the third chemical liquid and the fourth chemical liquid.

  As the chemical solution, any one of an acid system, an alkali system, an oxidation system, and a reduction system is used. For example, as a preferred example, an oxidizing agent or a reducing agent is used for the first chemical solution, and these are supplied to the substrate at times t1 to t2. These chemical solutions weaken or denature etching residues on the substrate surface. Next, acid or alkali is used for the second chemical solution, and these are supplied to the substrate at times t2 to t3. These chemicals promote dissolution of the residue. Finally, rinsing with the base solution is performed at times t3 to t4. In addition, since the waste liquid used by washing | cleaning is 95% or more, it can process in a factory.

  A preferable condition required for the base solution is a medium having high solubility in the chemical solution to be added. More specifically, water is the main component. Moreover, it is desirable that the water used for the base liquid is water in which the dissolved gas concentration is controlled. Specifically, water from which dissolved gas has been degassed, or a single or multiple gases selected from carbon dioxide, nitrogen, oxygen, helium, neon, and argon are dissolved at a constant concentration below the saturation concentration at atmospheric pressure. Water.

  In the present invention, an oxidizing agent is added to the base solution to oxidize the semiconductor surface that is the object to be cleaned, or conversely, a reducing agent is added to reduce the semiconductor surface. At that time, the fluctuation of the amount of dissolved oxygen contained in the base liquid fluctuates the effect of oxidation and reduction, which leads to a decrease in the reproducibility of the cleanliness of the semiconductor substrate after cleaning. Absent.

  On the other hand, in the present invention, an acid or an alkali is added to the base liquid to change the pH of the cleaning liquid supplied onto the semiconductor substrate. However, the dissolved carbon dioxide that exhibits acid properties in a dissolved state is used. When the amount varies, the pH of the cleaning liquid supplied to the semiconductor substrate varies, and the reproducibility of the cleanliness of the semiconductor substrate after cleaning decreases.

  As a base solution, fluctuations in the amount of dissolved oxygen and carbon dioxide can be suppressed by using deaerated water from which gas dissolved in water has been removed, but during handling in air, In consideration of minimizing fluctuations in dissolved gas concentration, the above fluctuations can also be achieved by dissolving carbon dioxide, nitrogen, oxygen, helium, neon and argon in advance at a constant concentration below the saturation concentration at atmospheric pressure. Can be suppressed. However, if these gases are dissolved above the saturation concentration at atmospheric pressure (supersaturation), bubbles are generated in the chemical solution during the cleaning process under atmospheric pressure, and the cleaning efficiency is increased. Since it may reduce, it is not preferable. In addition, after performing the operation (degassing) of removing dissolved oxygen from ultrapure water, carbon dioxide is slightly dissolved so that ultrapure water flowing in a pipe such as Teflon (registered trademark) is not charged. Even water can be used as a base solution.

  Further, the base solution may be an aqueous solution containing a salt. Salts to be dissolved include ammonium sulfate, ammonium hydrochloride, ammonium fluoride, ammonium nitrate, ammonium phosphate, tetramethylammonium sulfate, tetramethylammonium hydrochloride, tetramethylammonium fluoride, tetramethylammonium nitrate, tetramethylammonium phosphate, potassium sulfate , Potassium chloride, potassium fluoride, potassium nitrate, and potassium phosphate.

More preferably, the base solution is an aqueous solution containing a fluoride salt (particularly ammonium fluoride). When the fluoride salt is dissolved in the base liquid, it is possible to liberate HF (hydrofluoric acid) in a weak acid by adding an acid, further HF and F ^- high for washing objects ^- generated from HF2 It is considered to exhibit solubility. By dissolving the salt, it may be easy to control the pH change when an acid or alkali is added. “Easy to control” means that the pH change is not steep when an acid or alkali is added, and a so-called buffering action may be used.

  Next, an embodiment of the cleaning method of the present invention will be described in detail with reference to the drawings. FIG. 4 is a schematic cross-sectional view of a single wafer spin cleaning apparatus according to an embodiment of the present invention. The disc-shaped chuck 10 is rotated by a motor (not shown) so that the silicon wafer 12 is rotatably held on the chuck 10. Preferably, the silicon wafer 12 is held somewhat apart from the surface of the chuck 10 by Bernoulli or an air bearing by an inert gas or the like ejected from the chuck 10. A plurality of protruding claws 14 are provided on the surface of the chuck 10 corresponding to the outer shape of the silicon wafer 12, the outer edge of the silicon wafer 12 contacts the claws 14, and the silicon wafer 12 rotates in a stable orbit. Is done. The silicon wafer 12 has a diameter of 300 mm, for example.

  One or a plurality of nozzles 20 for supplying a cleaning liquid and a rinsing liquid are attached to the upper portion of the chuck 10. The nozzle 20 is connected to a storage chamber for chemicals and the like (not shown). The nozzle 20 is not necessarily fixed in position, and may be configured to move as necessary.

  A cylindrical cup 30 is attached so as to substantially cover the outer periphery of the chuck 10. The cup 30 collects the cleaning liquid and the rinsing liquid blown from the surface of the silicon wafer 12 so as not to be scattered outside. The collected waste liquid is stored at the bottom of the cup 30 and discharged from the drain groove 32 to the outside of the cup 30.

  FIG. 5 is a block diagram showing an electrical configuration of the single wafer spin cleaning apparatus. The single wafer cleaning apparatus includes an input unit 100 for inputting an instruction from a user, a cleaning liquid control unit 110 for adjusting the type, amount, timing, and the like of the cleaning liquid supplied from the nozzle 20, and a drive for controlling rotation driving of the chuck 10. A control unit 120, a display control unit 140 that displays information on the display 130, a wafer detection sensor 150 that detects that the wafer 12 is placed on the chuck 10, and a monitoring unit that monitors the chemical solution supplied from the nozzle 20 152, a data memory 160 that stores data such as calculation results and cleaning recipes, a program memory 170 that stores programs such as a cleaning processing sequence, and a central processing unit 180 that controls each unit according to the programs.

  Next, a cleaning liquid supply system in the single wafer spin cleaning apparatus of this embodiment will be described. FIG. 6 is a diagram showing an outline of a cleaning liquid supply system. The supply system includes a base liquid storage unit 200 that stores a base liquid of a cleaning liquid, an acid chemical liquid storage unit 210 that stores an acidic chemical liquid, an alkaline chemical liquid storage unit 220 that stores an alkaline chemical liquid, an oxidant storage unit 230, and And a reducing agent storage unit 240 for storing the reducing agent. A flow rate adjustment valve 202 is connected between the base liquid storage unit 200 and the nozzle 20. Flow rate adjusting valves 212, 214, 216, and 218 are also connected to the acid chemical solution storage unit 210, the alkaline chemical solution storage unit 220, the oxidant storage unit 230, and the reducing agent storage unit 240, respectively. In addition, the storage part of the pure water used for the rinse process is abbreviate | omitted here.

  The flow rate adjusting valve 202 controls the timing and flow rate of supplying the base liquid in response to the control signal S from the cleaning liquid control unit 110, and the other acid chemical liquid storage unit 210, alkaline chemical liquid storage unit 220, and oxidant storage. The chemical solution supplied from the unit 230 and the reducing agent storage unit 240 can be mixed. The cleaning liquid output from the flow rate adjusting valve 202 is dropped or sprayed onto the substrate from the nozzle 20. The flow rate adjusting valves 212, 214, 216, and 218 supply the acid chemical solution, the alkaline chemical solution, the oxidizing agent, and the reducing agent in response to the control signals S 1, S 2, S 3, and S 4 from the cleaning liquid control unit 110. To control.

  The monitoring unit 152 monitors whether or not the cleaning liquid supplied from the flow rate adjustment valve 202 to the nozzle 20 contains a predetermined chemical solution, and outputs the monitoring result to the central processing unit 180. The monitoring unit 152 measures the flow rate Q per unit time of the cleaning liquid after mixing the chemicals by the flow rate adjusting valve 202. The central processing unit 180 compares the flow rate Q obtained from the monitoring unit 152 with the flow rate Q1 obtained by summing the unit time chemicals supplied by the flow rate adjustment valves 212, 214, 216, and 218. Determine whether or not. If they match, it is determined that a predetermined chemical solution is mixed, but when the flow rate Q <Q1, it is determined that the predetermined chemical solution is not mixed, and a cleaning liquid error is displayed on the display 130 via the display control unit 140. Display the alarm. In addition to this, the cleaning liquid control unit 110 stops the supply of all the chemical liquids by the control signals S1, S2, S3, and S4. In addition to checking the flow rate as described above, the monitoring unit 152 irradiates the cleaning liquid with near infrared light, for example, and checks whether the cleaning liquid contains a certain chemical component based on the light absorption rate. It may be.

  The cleaning liquid control unit 110 can control the flow rate adjustment valves 202 and 212 to 218 in accordance with the cleaning recipe stored in the data memory 160. The cleaning recipe is a cleaning processing sequence in which the type, order, time, flow rate, and the like of the chemical solution to be mixed with the base solution are defined in advance, and the data memory 160 stores the cleaning recipe as shown in FIG. For example, when the cleaning recipe # 1 corresponds to the cleaning sequence shown in FIG. 1A, the base liquid is supplied with the flow rate Q during the time t0-t5, and the oxidizing agent is used as the first chemical liquid P1 at the time t1-. It is previously stored that the flow rate Q1 is supplied during t2, and the acid chemical solution is supplied as the second chemical solution P2 during the time t3-t4. The cleaning liquid control unit 110 controls the timing and flow rate of the flow rate adjusting valves 202 and 212 to 218 according to the content of the cleaning recipe # 1.

  The cleaning recipe can be determined by other methods besides those shown in FIG. The cleaning processing time may be divided into fixed time intervals, and the chemical solution may be selected in each division. For example, as shown in FIG. 8A, the cleaning process for 1 minute is divided into 10-second intervals, and the flow rate of the chemical solution in each section is selected. The flow rate of the chemical solution may be two steps of ON (flow) or OFF (no flow), or may be selected from three steps of flow rate 1, flow rate 2, and flow rate 3.

  The cleaning recipe is selected from a plurality of combinations shown in FIG. FIG. 8B shows an example of the cleaning recipe # 2. Cleaning recipe # 2 mixes the base chemical with 0-10 (s), 10-20 (s), alkaline chemicals at a flow rate of 3, and 30-30 (s) with oxidant. Mixing at a flow rate of 2, supplying a base solution without mixing any chemical solution for 30-40 (s), mixing an acidic chemical solution at a flow rate of 1 for 50-50 (s), 50- In the section of 60 (s), the cleaning sequence is such that only the base solution is supplied without mixing any chemical solution.

  The cleaning recipe stored in the data memory 160 can be displayed on the display by the display control unit 140. For example, when starting the cleaning process, the user instructs the display of the cleaning recipe from the input unit 100, and the central processing unit 180 displays the cleaning recipe stored in the data memory 160 in response to this command. Is displayed on the display 130. When the user selects a desired cleaning recipe from a plurality of cleaning recipes, the central processing unit 180 executes the cleaning recipe according to the cleaning processing program in the program memory 170.

  In addition to the selection by the user, the cleaning recipe may be automatically selected in response to the process of the semiconductor process. For example, the cleaning recipe # 1 may be selected for cleaning after etching the metal wiring material, and the cleaning recipes # 2 and # 5 may be selected for cleaning after etching the interlayer insulating film. Preferably, the program memory 170 (see FIG. 5) of the single wafer cleaning apparatus stores a program for determining which cleaning recipe is selected in accordance with the process of the semiconductor process. The device 180 controls the operation of the cleaning liquid control unit 110 and the like according to this program.

  FIG. 9 shows an operation flow when a cleaning recipe is selected in response to a process of a semiconductor process. When the first process on the silicon wafer 12 is completed (step S101), the silicon wafer is mounted on the chuck 10 (see FIG. 4) of the single wafer cleaning apparatus via a transfer mechanism (not shown). Wafer detection sensor 150 detects the wafer and outputs the detection result to central processing unit 180. The central processing unit 180 refers to the data memory 160 and selects the first cleaning recipe after the first process (step S102). The central processing unit 180 controls the cleaning liquid control unit 110 based on the selected first cleaning recipe, thereby controlling the timing and flow rate of the chemical liquid added to the base liquid, and the surface of the silicon wafer is controlled by the first cleaning liquid. Washing is performed (step S103).

  When the cleaning with the first cleaning liquid is completed, the silicon wafer is transferred from the single wafer cleaning device to another processing chamber via a transfer mechanism (not shown), and the second process is performed on the silicon wafer ( Step S104). When the second process ends (step S105), the silicon wafer is again mounted on the chuck 10 of the single wafer cleaning apparatus. After confirming that the mounted silicon wafer is accurately positioned by the detection sensor 150, the central processing unit 180 selects the second cleaning liquid after the second process (step S106), and the second cleaning recipe. Accordingly, the cleaning liquid control unit 110 is controlled to control the timing and flow rate of the chemical liquid added to the base liquid, and the silicon wafer is cleaned with the second cleaning liquid (step S107).

  The operation flow of FIG. 9 is directed to the cleaning of the silicon wafer after the first and second processes. Of course, cleaning recipes corresponding to more processes such as the third and fourth processes are automatically selected. You may make it choose. The selection of the cleaning recipe can be made to follow a cleaning sequence corresponding to a predetermined process sequence.

  Next, an example of cleaning by the single wafer spin cleaning apparatus of this embodiment will be described. In FIG. 10A, an insulating film layer 302 is formed on a lower wiring layer 300 on a silicon substrate, and a W wiring layer 306 is formed in a via hole formed in the insulating film layer 302 via a W silicide layer 304. , A cap layer 308, an Al—Cu wiring layer 310, and a cap layer 312 are formed on the W wiring layer 306 by etching. Due to dry etching of the cap layers 308 and 312 or the Al—Cu wiring layer 310, etching residues 320 such as sidewall polymers and rabbit ears are easily formed on the side walls of the Al—Cu layer 310. Further, when the resist mask for etching is removed by ashing such as oxygen plasma, an ashing residue (backbone) 330 is easily formed on the surface of the cap layer 312.

  An optimal cleaning recipe for removing the etching residue 320 and / or the ashing residue 330 is selected and executed by the central processing unit 180. The operation will be described with reference to the flow of FIG.

  First, a cleaning recipe is selected (step S201). The selection of the cleaning recipe may be made by the user, but is preferably automatically selected by the program associated with the semiconductor substrate processing process as described above.

  When a cleaning recipe is selected, the central processing unit 180 controls the cleaning liquid control unit 110 and the drive control unit 120 based on the selected cleaning recipe, and a desired chemical solution is mixed with the base liquid within the cleaning processing period. The liquid is dropped from the nozzle onto the substrate surface. Further, the substrate is rotated at the number of rotations corresponding to the cleaning recipe.

  The cleaning liquid control unit 110 controls the flow rate adjustment valve 202 via the control signal S, and starts supplying the base liquid from the base liquid storage unit 200 (see FIG. 6) (step S202). The base solution contains 0.5 wt% or less of the fluorine-containing compound, which is supplied at a constant flow rate, preferably 100 ml / min to 2 liter / min.

  Next, the cleaning liquid control unit 110 controls the flow rate adjustment valve 212 via the control signal S1, and after 1 to 20 seconds from the start of supply of the base liquid, sulfuric acid, hydrochloric acid, hydrofluoric acid, nitric acid from the acid chemical liquid storage unit 210. Alternatively, the supply of the acid chemical solution containing any one of phosphoric acid is started (step S203). The acid chemical liquid has a flow rate of 1/10 to 1/1000 of the base liquid, and a cleaning liquid in which the acid chemical liquid is mixed with the base liquid is dropped onto the substrate surface. The cleaning liquid control unit 110 stops the supply of the acid chemical liquid after 5 to 40 seconds via the control signal S1 (step S204).

  Next, the cleaning liquid control unit 110 supplies the base liquid at a constant flow rate (100 milliliters / minute to 2 liters / minute) for a predetermined time (5 to 60 seconds), and stops supplying the base liquid (step S205). Then, the base liquid is rinsed with pure water (step S206).

  In the above flow, the processing time is 2 minutes or less, and single-wafer spin cleaning in which the chemical solution is disposable is performed. As a result, the etching residue 320 and the ashing residue 330 shown in FIG. 10A are removed, and FIG. It becomes a clean surface as shown in).

  FIG. 12A shows a state in which an Al—Cu wiring layer 400, a cap layer 402, and an insulating film layer 404 are formed on a silicon substrate, and a via hole 406 or a contact hole is formed in the insulating film layer 404. . Etching residue 410 such as a sidewall polymer or a crown is easily formed on the sidewall of the via hole 406 by dry etching of the insulating film layer 404. Further, when the resist mask for etching is removed by ashing such as oxygen plasma, an ashing residue 420 is easily formed on the surface of the insulating film layer 404.

  The optimum cleaning recipe for removing the etching residue 410 and / or the ashing residue 420 is automatically selected and executed by the central processing unit 180. The operation will be described with reference to the flow of FIG.

  An optimum cleaning recipe for removing etching residues and ashing residues as shown in FIG. 12A is selected (step S301). Next, the cleaning liquid control unit 110 controls the flow rate adjustment valve 202 via the control signal S, and starts supplying the base liquid from the base liquid storage unit 200 (see FIG. 5) (step S302). In this cleaning step, the base solution contains 0.5 wt% or less of a fluorine-containing compound and 0.5 w% or less of a substance that activates an oxidizing agent or a reducing agent, which has a constant flow rate, preferably from 100 ml / min. Supplied at 2 liters / minute.

  Next, the cleaning liquid control unit 110 controls the flow rate adjustment valve 214 via the control signal S2, and after 1 to 20 seconds from the start of the supply of the base liquid, ammonia, tetramethylammonium hydroxide ( The supply of an alkaline chemical solution containing any one of TMAH) and potassium hydroxide (KOH) is started, and the cleaning liquid control unit 110 controls the flow rate adjustment valve 218 via the control signal S4 to store the reducing agent. The supply of the reducing agent containing any one of hydroxylamine (HA), hydrazine (HH), or a salt thereof is started from the unit 240 (step S303).

  The alkaline chemical liquid and the reducing agent are each at a flow rate of 1/10 to 1/1000 of the base liquid, and a cleaning liquid in which the alkaline chemical liquid and the reducing agent are mixed with the base liquid is dropped onto the substrate surface. The cleaning liquid control unit 110 stops supplying the alkaline chemical liquid and the reducing agent after 5 to 40 seconds via the control signals S2 and S4 (step S304).

  Next, the cleaning liquid control unit 110 controls the flow rate adjustment valve 214 via the control signal S2, and after 1 to 20 seconds from the start of the supply of the base liquid, ammonia, tetramethylammonium hydroxide ( Supply of the alkaline chemical solution containing any one of TMAH) and potassium hydroxide (KOH) is started (step S305).

  The alkaline chemical liquid has a flow rate that is 1/10 to 1000 times that of the base liquid. The cleaning liquid control unit 110 stops supplying the alkaline chemical solution after 5 to 40 seconds via the control signal S2 (step S306). As described above, when the alkaline chemical liquid is continuously supplied in steps S304 to S305, the supply of the alkaline chemical liquid may be continuously performed without stopping.

  Next, the cleaning liquid control unit 110 controls the flow rate adjustment valve 212 via the control signal S1, and the acid chemical liquid storage unit 210 supplies an acid containing any one of sulfuric acid, hydrochloric acid, hydrofluoric acid, nitric acid, or phosphoric acid. Supply of the system chemical solution is started (step S307). The acid chemical solution has a flow rate of 1/10 to 1000 times that of the base solution. The cleaning liquid control unit 110 stops the supply of the acid chemical liquid after 5 to 40 seconds via the control signal S1 (step S308).

  Next, the cleaning liquid control unit 110 supplies the base liquid at a constant flow rate (100 milliliters / minute to 2 liters / minute) for a predetermined time (5 to 60 seconds), and stops the supply of the base liquid (step S309). Then, the base liquid is rinsed with pure water (step S310).

  In the above flow, the processing time is 2 minutes or less and single-wafer spin cleaning in which the chemical solution is made disposable is performed. As a result, the etching residue 410 and the ashing residue 420 shown in FIG. 12A are removed, and FIG. It becomes a clean surface as shown in).

  According to the cleaning method of the present invention, the cleaning after the etching of the metal wiring material as shown in FIG. 10A and the cleaning after the etching of the interlayer insulating film as shown in FIG. On the other hand, when cleaning the interlayer insulation film after etching and cleaning the metal wiring material after etching, control the timing and flow rate of the chemical solution added to the base solution to generate a cleaning solution suitable for any cleaning. In addition, it is possible to provide a single wafer spin cleaning apparatus that can be cleaned with the cleaning liquid and flexibly corresponds to a semiconductor processing process.

  FIG. 14 is a cross-sectional view showing an example of a dual damascene process when forming a buried Cu wiring. As shown in FIG. 2A, an insulating film layer 500, an etching stopper layer 502, a low dielectric constant insulating film layer 504, and a cap insulating film 506 are formed on the substrate. A barrier layer 530 and a Cu buried wiring 532 are formed in the openings formed in the low dielectric constant insulating film layer 504 and the cap insulating layer 506.

  From this state, an antireflection film 510 and a resist film 512 are formed as shown in FIG. 5B, and the resist layer 512 is exposed and developed as shown in FIG. Opening 512a is formed. Next, as shown in FIG. 4D, dry etching is performed using the resist layer 512 as a mask until the etch stopper layer 502 is exposed, thereby forming a via hole 514. Next, as shown in FIG. 6E, after removing the resist layer 512 and the antireflection film 510, the antireflection film 516 and the resist layer 518 are covered so as to cover the via hole 514 as shown in FIG. Form.

  Next, as shown in FIG. 15G, the resist layer 518 is exposed and developed, and the resist layer 518 is patterned. At this time, the opening 518 a formed in the resist layer 518 is larger than the diameter of the via hole 514. Next, as shown in FIG. 6H, dry etching is performed using the resist layer 518 as a mask to form a wiring groove 520. Next, as shown in FIG. 5I, a barrier layer 522 and a Cu layer 524 are formed so as to cover the via hole 514 and the wiring groove 520. Next, as shown in FIG. 6J, the barrier layer 522 and the Cu layer 524 are removed by chemical mechanical polishing (CMP), and the substrate surface is planarized.

  In the dual damascene process, after the dry etching process shown in FIG. 14D, the dry etching process shown in FIG. 15H, and the CMP process shown in FIG. 15J, cleaning is performed to remove etching residues and the like. A process is performed.

  As shown in FIG. 16A, after the dry etching step shown in FIG. 14D, a sidewall polymer 540 such as Si, Cu, Ti, or resist is formed on the sidewall of the via hole 514 or the substrate surface. In the state after cleaning with the cleaning liquid, as shown in FIG. 16B, etching residues such as the sidewall polymer 540 are removed.

  Similarly, as shown in FIG. 16C, etching residues such as the sidewall polymer 542 are formed after the dry etching for forming the wiring groove 520 according to FIG. For this reason, this is removed by the cleaning liquid to obtain the state of FIG. Further, as shown in FIG. 16 (e), after CMP according to FIG. 15 (j), slurry residue 544 and metal contaminants 546 may be formed on the surface of the Cu layer 524, and this is cleaned with a cleaning liquid. Thus, the state of FIG. 16F can be obtained.

  As described above, some processes included in the dual damascene process require cleaning with a cleaning liquid, and an optimal cleaning recipe is selected for those processes, and a silicon wafer is cleaned based on the selected cleaning recipe. Can do. A cleaning recipe including conditions such as the chemical component of the cleaning liquid, the supply time, and the rotation speed of the wafer is stored in advance in the data memory, and an optimal cleaning recipe is selected from the data. The selection may be based on an instruction from the user, but the cleaning recipe associated with the process sequence may be automatically selected.

  Although the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. Is possible.

  The cleaning method and the cleaning apparatus according to the present invention can be used in a single wafer cleaning process of a thin plate such as a silicon semiconductor substrate or a compound semiconductor substrate.

It is a figure explaining the concept of the washing | cleaning method of this invention. It is a figure explaining the concept of the washing | cleaning method of this invention. It is a figure explaining the concept of the washing | cleaning method of this invention. It is a fragmentary sectional view which shows the general structure of a single wafer type spin washing apparatus. It is a block diagram which shows the electrical structure of a single wafer type spin washing apparatus. It is a figure explaining the supply system of the washing | cleaning liquid in the single wafer type spin apparatus which concerns on the Example of this invention. It is a figure explaining the washing | cleaning recipe in the single wafer type spin apparatus which concerns on the Example of this invention. It is a figure explaining another cleaning recipe. It is a figure which shows the operation | movement flow of the washing | cleaning method corresponding to the process of a silicon wafer. FIG. 10A shows the state of the silicon substrate surface to which the residue after etching or ashing of the metal wiring material is attached, and FIG. 10B is the case where the residue is removed by the single wafer spin cleaning of this embodiment. Shows the state. It is a flow which shows the cleaning process after the etching of metal wiring material or after ashing. FIG. 12A shows the state of the silicon substrate surface to which the residue after the interlayer insulating film etching or after ashing is attached, and FIG. 12B shows the residue removed by the single wafer spin cleaning of this embodiment. Indicates the state. 10 is a flow showing a cleaning process after etching or ashing of an interlayer insulating film material. FIGS. 14A to 14F are schematic cross-sectional views illustrating a dual damascene process for forming a Cu buried wiring. FIGS. 15G to 15J are schematic cross-sectional views illustrating a dual damascene process for forming a Cu buried wiring. FIGS. 16A to 16F are diagrams illustrating a cleaning process corresponding to the dual damascene process. It is a figure explaining the conventional mixed chemical | medical solution with which several components were mixed.

Explanation of symbols

10: Chuck 12: Silicon wafer 14: Claw 20: Nozzle 30: Cup 32: Drain groove 100: Input unit 110: Cleaning liquid control unit 120: Drive control unit 130: Display 140: Display control unit 150: Wafer detection sensor 160: Data Memory 170: Program memory 180: Central processing unit 200: Base liquid storage unit 202: Flow rate adjustment valve 210: Acidic chemical solution storage units 212 to 218: Flow rate adjustment valve 220: Alkaline chemical solution storage unit 230: Oxidant storage unit 240: Reducing agent storage unit 300: lower wiring layer 302: insulating film layer 304: W silicide layer 306: W wiring layer 308: cap layer 310: Al—Cu wiring layer 320: etching residue 330: ashing residue 400: Al—Cu wiring layer 402: Cap layer 404: Insulating film layer 406: Beer ho 410: Etching residue 420: Ashing residue 500: Insulating film layer 502: Etching stopper layer 504: Low dielectric constant insulating film layer 506: Cap insulating film 510: Antireflection film 512: Resist layer 512a: Opening 514: Via hole 516: Antireflection Film 518: Resist layer 520: Wiring groove 522: Barrier layer 524: Cu layer 540: Side wall polymer 542: Side wall polymer 544: Slurry residue 546: Metal contaminant P1: First chemical liquid P2: Second chemical liquid B: Base solution

Claims (28)

A cleaning method for cleaning a semiconductor substrate using a cleaning solution,
Prepare a base solution for cleaning,
Supply the base solution on the semiconductor substrate,
Adding a first chemical liquid to the base liquid at a first timing, and supplying a first cleaning liquid in which the first chemical liquid is added to the base liquid onto the semiconductor substrate;
Stop adding the first chemical to the base solution at the second timing,
Adding a second chemical liquid to the base liquid at a third timing, and supplying a second cleaning liquid in which the second chemical liquid is added to the base liquid onto the semiconductor substrate;
Stop adding the second chemical to the base solution at the fourth timing;
A cleaning method comprising steps. The cleaning method according to claim 1, wherein the third timing is temporally faster than the second timing. The cleaning method according to claim 1, wherein the third timing is separated from the second timing by a predetermined time. The cleaning method according to claim 1, wherein the third and fourth timings are intermittently repeated between the first and second timings. The cleaning method according to claim 1, wherein the period of the first and second timings and the period of the third and fourth timings are alternately repeated. The cleaning method according to claim 2, wherein the fourth timing is temporally faster than the second timing. The cleaning method further includes adding a third chemical liquid to the base liquid at a fifth timing, supplying a third cleaning liquid in which the third chemical liquid is added to the base liquid onto the semiconductor substrate, and at a sixth timing. The washing | cleaning method of Claim 1 including the step which stops the addition to the base liquid of 3 chemical | medical solutions. The cleaning method further includes adding the fourth chemical liquid to the base liquid at the seventh timing, supplying the fourth cleaning liquid with the fourth chemical liquid added to the base liquid onto the semiconductor substrate, and supplying the fourth chemical liquid to the base liquid at the eighth timing. The washing | cleaning method of Claim 7 including the step of stopping the addition to the base liquid of 4 chemical | medical solutions. The cleaning method according to any one of claims 1 to 8, wherein the base liquid is water having a dissolved gas concentration controlled. The base liquid is water in which a single gas or a plurality of gases selected from carbon dioxide, nitrogen, oxygen, helium, neon, and argon are dissolved at a constant concentration not higher than a saturated concentration at atmospheric pressure. The cleaning method according to claim 9. The cleaning method according to claim 1, wherein the base solution is an aqueous solution containing a salt. Base solution is ammonium sulfate, ammonium hydrochloride, ammonium fluoride, ammonium nitrate, ammonium phosphate, tetramethylammonium sulfate, tetramethylammonium chloride, tetramethylammonium fluoride, tetramethylammonium nitrate, tetramethylammonium phosphate, potassium sulfate, chloride The cleaning method according to claim 11, comprising a single salt or a plurality of salts selected from potassium, potassium fluoride, potassium nitrate, and potassium phosphate. The first, second, third or fourth chemical liquid is a liquid mainly composed of an acid, a liquid mainly composed of an alkali, a liquid mainly composed of an oxidizing substance, or a liquid mainly composed of a reducing substance. The cleaning method according to claim 1, wherein the cleaning method is any one of the above. The cleaning method according to claim 13, wherein the liquid containing the acid as a main component is an aqueous solution containing any one of sulfuric acid, hydrochloric acid, hydrofluoric acid, nitric acid, and phosphoric acid. The cleaning method according to claim 13, wherein the alkali-based liquid is an aqueous solution containing any of ammonia, tetramethylammonium hydroxide, and potassium hydroxide. The cleaning method according to claim 13, wherein the liquid containing the oxidizing substance as a main component is an aqueous solution containing hydrogen peroxide. The cleaning method according to claim 13, wherein the liquid containing the reducing substance as a main component is an aqueous solution containing any of hydroxylamine, hydrazine, and salts thereof. A cleaning method for cleaning a semiconductor substrate using a cleaning solution,
Prepare multiple cleaning recipes,
After the first process to the semiconductor substrate is performed, the semiconductor substrate is cleaned by a first cleaning recipe selected from the plurality of cleaning recipes,
Cleaning a semiconductor substrate with a second cleaning recipe selected from among the plurality of cleaning recipes after a second process is performed on the semiconductor substrate cleaned with the first cleaning liquid;
The first and second cleaning recipes are cleaning methods in which a cleaning liquid is generated by adding different chemicals to a base liquid for cleaning. The first process includes a step of forming a via hole or a contact hole in the insulating film on the surface of the semiconductor substrate by etching, or a step of forming a metal wiring pattern by etching a metal material on the surface of the semiconductor substrate. 19. The cleaning method according to claim 18, comprising a step of forming a metal wiring pattern by etching a metal material on a surface of the semiconductor substrate or a step of forming a via hole or a contact hole in an insulating film on the surface of the semiconductor substrate by etching. The first process is a step of forming via holes, contact holes, or wiring grooves in the insulating film on the surface of the semiconductor substrate by etching or polishing and removing the metal material on the surface of the semiconductor substrate by chemical mechanical polishing to form a buried metal wiring The second process includes a step of polishing and removing the metal material on the surface of the conductor substrate by chemical mechanical polishing to form a buried metal wiring, or a via hole, a contact hole, or a wiring in the insulating film on the surface of the semiconductor substrate. The cleaning method according to claim 18, comprising a step of forming the groove by etching. After the via hole or contact hole is formed by etching, the first or second cleaning recipe is:
Supplying a base solution containing a fluorine-containing compound on a semiconductor substrate;
Adding a chemical solution containing an alkaline chemical solution and a reducing substance to the base solution at a first timing, and supplying a first cleaning liquid obtained by the addition onto the semiconductor substrate;
Stop the addition of the alkaline chemical and the chemical containing the reducing substance at the second timing,
At the third timing, an alkaline chemical solution is added to the base solution, and the second cleaning solution obtained by the addition is supplied to the semiconductor substrate,
Stop adding alkaline chemicals at the fourth timing,
An acid chemical solution is added to the base solution at the fifth timing, and a third cleaning solution obtained by the addition is supplied onto the semiconductor substrate,
Stop adding the acid chemical at the sixth timing,
The cleaning method according to claim 18 or 19. The first or second cleaning recipe after the metal wiring pattern is formed is
Supplying a base solution containing a fluorine-containing compound on a semiconductor substrate;
The acid chemical solution is added to the base solution at the first timing, and the first cleaning solution obtained by the addition is supplied onto the semiconductor substrate,
Stop the addition of the acid chemical at the second timing,
At the third timing, an alkaline chemical solution is added to the base solution, and the second cleaning solution obtained by the addition is supplied to the semiconductor substrate,
Stop adding the alkaline chemical at the fourth timing,
The cleaning method according to claim 18 or 19. A single wafer cleaning apparatus for cleaning a semiconductor substrate with a cleaning liquid,
Holding means for rotatably holding the semiconductor substrate;
Supply means for supplying a cleaning liquid onto the semiconductor substrate;
Base liquid storage means for storing a base liquid for cleaning;
First chemical storage means for storing a first chemical added to the base solution;
A second chemical storage means for storing a second chemical added to the base solution;
The first chemical liquid is added to the base liquid to generate a first cleaning liquid, or the second chemical liquid is added to the base liquid to generate a second cleaning liquid, and the first or second cleaning liquid is supplied to the supply unit. Cleaning liquid control means to be supplied onto the semiconductor substrate from,
Having a cleaning device. The cleaning device further includes third and fourth chemical liquid storage means for storing a third chemical liquid and a fourth chemical liquid, and the cleaning liquid control means adds the third chemical liquid to the base liquid to add a third cleaning liquid. The cleaning device according to claim 23, wherein the fourth cleaning liquid is generated by adding the fourth chemical liquid to the base liquid. The cleaning apparatus according to claim 23 or 24, wherein the cleaning liquid control means controls the timing at which the chemical liquid should be added and the amount of the chemical liquid added to the base liquid. The cleaning apparatus further includes a storage unit that stores a plurality of cleaning recipes, and a selection unit that selects a predetermined cleaning recipe from the plurality of cleaning recipes, and the cleaning liquid control unit is configured to select the first or the first according to the selected cleaning recipe. The cleaning device according to claim 23, wherein the cleaning device generates two cleaning liquids. The first, second, third or fourth chemical liquid is a liquid mainly composed of an acid, a liquid mainly composed of an alkali, a liquid mainly composed of an oxidizing substance, or a liquid mainly composed of a reducing substance. The cleaning apparatus according to any one of claims 23 to 26, wherein the cleaning apparatus is any one of the above. 28. The cleaning device further includes monitoring means for monitoring the first or second cleaning liquid generated by the cleaning liquid control means and stopping generation of the cleaning liquid by the cleaning liquid control means based on a monitoring result. The cleaning device according to claim 1.

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