WO2019145485A1 - Method and device for treating etched surfaces of a semiconductor substrate using a ozone-containing medium - Google Patents

Abstract

The invention relates to a method for treating a surface of a textured silicon substrate, comprising an ozone-based treatment of the surface of the textured silicon substrate to remove porous silicon and/or to cause a metal cleaning and/or a cleaning of organic compounds.

Description

 Method and apparatus for treating etched surfaces of a semiconductor substrate using ozone-containing medium

description

The present invention relates to a method and apparatus for treating a surface of a textured silicon substrate. More particularly, the present invention relates to a method of treating etched surfaces of a semiconductor substrate using ozone-containing medium, wherein such semiconductor substrates are applicable to, for example, photovoltaic modules. Exemplary embodiments relate to a method for cleaning etched surfaces of a semiconductor substrate and / or for post-cleaning of multicrystalline diamond wire-sawn silicon substrates. Treatment of a textured silicon substrate may involve cleaning thereof, which may be done using, for example, an ozone-containing medium.

Semiconductor substrates may be textured during their further processing, that is, the surface of the semiconductor substrate may be treated, such as to perform a roughening. Texturing can be obtained, for example, by means of an acidic texture in the inline process. These are described, for example, in US 2010/0055398 A1 or EP 2 232 526 B1.

An apparatus and a method for the asymmetric alkaline texture of surfaces is described in DE 10 2013 218 693 A1.

A texture can also be obtained by acid etching, as described for example in US 2015/0040983 A1.

Diamond wire sawn multicrystalline wafers can also be textured.

Texturing can also be achieved with acidic media using additive or organic compounds. For this, an etching mixture may be used to produce a textured surface on silicon substrates. Such an etching mixture may comprise at least one polymer as thickening agent. In particular, can a polymer which is resistant to nitric acid and hydrofluoric acid and / or is a hydrophilic polymer. Such a polymer used as thickener may be selected from the group consisting of cellulose, especially methyl cellulose, polyvinyl alcohol and polyethylene oxide. In CN 103132079 A additives are described which consist of polyvinyl alcohol and polyethylene glycol alcohol.

A conventional method will be explained in detail with reference to FIG.

For example. the representation known from US Pat. No. 6,503,333 B2 and reproduced here as FIG. 7 shows that ozone can be used for rinsing. The steps 32 and 36 described therein relate to the two baths of RCA cleaning, wherein after each bath a quick dump rinse rinse comprising ozone (O3) is carried out. Also in DE 10 2010 054 370 A1 a use of ozone for cleaning is described. The alkaline etch process is combined with an additional purification step using hydrofluoric acid and ozone to provide a polished and clean surface used for Si0 ₂ / SiN _x sfapefpassivation. Here only a removal of detergent residues takes place.

A disadvantage of known methods is that they have a high complexity,

Accordingly, it would be desirable to have methods and apparatus for treating semiconductor substrates that are low in complexity.

The object of the present invention is therefore to provide a method for treating a surface of a textured silicon substrate and an apparatus for carrying out such a method, which have a low complexity.

This object is solved by the subject matter of the independent patent claims.

One finding of the present invention is to have realized that by using an ozone-based treatment, removal of porous silicon and / or metal cleaning, ie, removal of metal residues, can be obtained, such that an identical or comparable process step individually performs both purification steps or in combination, instead of performing an alkaline or an acid post-purification. This allows for low complexity since the same cleaning step can be used for different purposes. The use of Ozone-based treatment makes it possible to reduce the number of chemical process steps, since at the same time the porous silicon materials as well as the metals and / or organic components can be cleaned or removed. Thus, a further reduced low complexity can be obtained by reducing the number of rinsing steps by performing the purifications, the removal of the porous silicon and / or the metal cleaning or components simultaneously. This allows the reduction of the process time and thus an increase in throughput based on existing plants and / or processes. Furthermore, a reduction of the chemical consumption is made possible and a smaller dimension of the sequentially operating plants, that is, shorter plants. Furthermore, advantages obtained therefrom, in particular when the low consumption of chemicals in avoiding hydrogen chloride, potassium hydroxide and / or hydrogen peroxide, lies in the low cost of operating the plant. Also, the smaller number of purification steps makes it possible to obtain lower costs. Indirectly, disposal costs can also be saved since fewer (different) wastewater types are obtained. By incorporating media, less wastewater can be generated, reducing potential environmental challenges.

Examples provide a method of treating a surface of a textured silicon substrate. The method comprises ozone-based treatment of the surface of the textured silicon substrate to effect removal of porous silicon and / or metal cleaning and / or organic compound purification,

Examples provide an apparatus for carrying out such a method. Such apparatus includes process media supply means for providing an ozone-based treating medium and substrate handling means for positioning the silicon substrate to treat the surface.

Examples of the disclosure will be explained in more detail below with reference to the accompanying drawings. Show it:

Flg. Figure 1a is a schematic flow diagram of a prior art method;

1 b is a schematic flowchart of a method according to an embodiment; FIG. 2 is a schematic flow diagram of a method according to an embodiment having an optional step of cleaning organic compounds; FIG.

FIG. 3 is a schematic flow diagram of a method according to an embodiment including a step of simultaneously cleaning, removing porous silicon, and metal cleaning by means of the ozone-based treatment;

FIG. 4 is a schematic illustration of one for performing a method according to the present disclosure; FIG.

5 is a schematic illustration of an alternative example of an apparatus for carrying out a method according to the present disclosure, in which a substrate handling device is implemented as a horizontal transport system with rollers;

Fig. 6 is a schematic representation of an alternative example of a device for

 Performing a method according to the present disclosure, wherein a process media provider comprises a process media pool; and

7 is a schematic flowchart of a prior art method 1000.

Hereinafter, examples of the present invention will be described in detail and using the attached drawings. In the following description, many details are set forth in order to provide a more thorough explanation of examples of the disclosure. However, it will be apparent to those skilled in the art that other examples may be implemented without these specific details. The features of the different examples may be combined with each other unless features of a corresponding combination are mutually exclusive or such combination is expressly excluded. In the following, the same reference numerals are used for elements having the same or a similar function, so that even without a detailed embodiment, the description of these elements is interchangeable. FIG. 1 a shows a schematic flow diagram of a method 1000 according to the prior art. Step 1010 includes etching the semiconductor substrate to texure it. In a subsequent step 1020, the semiconductor substrate is rinsed in order to remove residues of substances or materials which have come into contact with the semiconductor substrate in step 1010. In a step 1030, an alkaline post-cleaning of the semiconductor substrate to remove porous silicon takes place. Thereafter, step 1020 is performed again to rinse the semiconductor substrate. In a step 1040, acidic post-cleaning of the semiconductor substrate for metal cleaning is performed. Thereafter, purging 1020 is again performed to clean the semiconductor substrate of acid post-cleaning residues 1040. In a step 1050, the semiconductor substrate is dried.

FIG. 1 b shows a schematic flowchart of a method 100 according to one exemplary embodiment. The method 100 comprises an optional step 110, in which an etching of the semiconductor substrate takes place, for instance in order to obtain a texturing of at least one surface of the semiconductor substrate.

One or more targets of the etch 110 and / or a major focus thereof may be on an acidic isotropic texture provided with an additive to treat multicrystalline diamond wire sawn silicon substrates. The additive may be organic or inorganic. An additive used may comprise as a component a polymer. The etching 110 can be carried out in various ways. One type is, for example, a metal-assisted chemical etching using metal particles. This can also be described by the English technical term "Metal Assisted Chemical Etching (MAGE)". It is also possible to use an acidic isotropic texture, ie mixture of substances. Such an acid isotropic texture with organic and / or inorganic additives may be, for example, a combination of hydrofluoric acid, nitric acid (HNO ₃ ) and at least one additive. Optionally, water can also be added so that the acid isotropic texture with additive can also be a combination of hydrofluoric acid, nitric acid, water and the additive. As described in DE 10 2016 210 883 A1, in the etching solution, with a small proportion of at most a few% by weight, an additive from the group consisting of alcohol, surfactant, glycol can be contained. By etching 110, etch rates and the appearance of the semiconductor substrate surface can be adjusted depending on the temperature and / or time. In one example, the etch may be done without additive. Typically, temperature ranges in the range of 10 ° C to 30 ° C and etches in the range of 0.5 minutes to 10 minutes may be used. Additive and / or additive residues may adhere to the surface and modify the wetting behavior for further steps and / or inhibit the attack of further etchants, ie inhibit. The additive may have one or more components and thus also be understood as an additive or a combination of several additives. The use of several additives may be such that the combination of the additives only work together in a solution or in the bath used, which means that, when the additives are combined in themselves, no interaction takes place yet. The detachment of impurities on the wafer, such as metals and / or metal ions, can also be inhibited.

Alternatively or additionally, an electrochemical etching can also be carried out. Other examples of use during the etching process include, for example, edge chemical isolation, surface smoothing, d. h., performing a polishing, selective emitter removal, removal of sawing damage, especially in diamond wire-sawn silicon substrates, treatment of only one major site (one-sided treatment) or treatment of both major sites (two-site treatment). That is, the use of an acidic isotropic texture may optionally be accomplished using an additive, which additive may be organic or inorganic.

The etching 110 may result in residues on at least one of the surfaces of the semiconductor substrate. These residues may be porous silicon, alternatively or additionally, texture additives, i. h., metal contaminants, but may alternatively or additionally include organic contaminants. According to an advantageous aspect of the present examples, the ozone-based treatment may be used to remove the porous silicon and / or perform the metal cleaning, that is to remove the metal residues.

For removal, in particular of the additive components, an optional step 120 may be carried out, in which a rinsing of the semiconductor substrate takes place. The rinsing 120 or the removal of the additive components can take place in at least one step and / or one pass. This means it can also be flushed more often. Rinsing 120 may include contacting the semiconductor substrate with water, that is, a medium of rinse 120 may be water. Alternatively or additionally, ozone, hydrofluoric acid, hydrogen chloride and / or other agents may also be used. The Flushing 120 may be in a temperature range of, for example, at least 5 ° C and at most 90 ° C, for example, to avoid the boiling of water. For example, a flushing operation, which may be termed "quick dumping rinse", may be used, overflow flushing and / or cascade flushing means may be used, for example, a flushing operation may involve a fixed flushing medium consumption, advantageously the flushing operation may dynamically affect the impurity level the wafer and / or the flushing medium can be adjusted.

Step 120 may be performed, in particular, if the method comprises step 110.

As an alternative to step 110, a pre-etched semiconductor substrate may also be provided for the ozone-based treatment step 130, with which removal of porous silicon and / or metal may be obtained. As explained in detail below, not only the removal of porous silicon and / or the metal cleaning can be carried out by the step. Rather, optionally also a cleaning of organic residues from the surface can be obtained, d. h., a cleaning by removing substances to be cleaned off.

The ozone-based treatment 130 may thus include the etching of porous silicon, i. h., the removal thereof, and combine the metal cleaning in one step, wherein each of the two cleaning aspects can be obtained independently, such as when no porous silicon or metal is present. If the ozone-based treatment is used only for one of the removal of porous silicon and the metal cleaning, then the other one can be omitted, or be carried out in a separate process step, for example. Before the ozone-based treatment. The removal of porous silicon on the surface of the textured silicon substrate may be carried out by an alkaline post-cleaning and / or by the treatment with ozone.

Exemplary embodiments envisage that the ozone-based treatment in step 130 is carried out together with, and in particular simultaneously with HF, in order simultaneously to carry out the removal of organic compounds and the metal cleaning.

Further exemplary embodiments provide that the ozone-based treatment in step 130 is carried out together with, and in particular simultaneously with, HCl in order to at the same time perform the removal of organic compounds and porous silicon.

Further embodiments combinatively provide that the ozone-based treatment is carried out in step 130 to effect at least the removal of porous silicon, the metal cleaning and the cleaning of organic compounds, which means that the three cleaning effects can be obtained simultaneously , Further embodiments therefore contemplate that treating 130 be carried out simultaneously to effect removal of porous silicon, metal cleaning, and organic compound purification.

Exports of the metal cleaning of the surface of the textured silicon substrate may be carried out by an acid post-cleaning and / or by the treatment with ozone. The metal cleaning can also be obtained by contacting the semi-egg substrate to be cleaned with an aqueous solution comprising water and at least one of hydrogen chloride (HCl) and hydrofluoric acid (HF). Alternatively or additionally, a solution comprising fiusic acid, hydrogen chloride and ozone can also be used.

Alternatively or additionally, the ozone treatment may also be used to remove organic residues. The ozone-based treatment 130 may, for example, be carried out in at least one step, which means that it may also be carried out repeatedly or iteratively.

Ozone concentrations of ozone contained, for example, in a liquid, such as aqueous solution in a bath in which the semiconductor substrate is dipped or which is sprayed over the semiconductor substrate may be in a range of at least 1 to at most 150 ppm. Preference is given to concentrations of at least 5 or at least 10 ppm, in particular more than 30 ppm, about 31 ppm or more, 35 ppm or more, 40 ppm or more or even 100 ppm or more. Such a solution may comprise water, an acid, hydrofluoric acid and / or hydrogen chloride. The solution may preferably have a pH in a range of at least 0 and at most 7 and be used at a process temperature of at least 5 ° C and at most 80 ° C. Preference is given to temperatures of at least 20 ° C and at most 65 ° C or at least 50 ° C and at most 65 ° C. Preferably, the solution is heated to temperatures above room temperature namely, taking into account the upper limit of 80 ° C, 65 ° C or 50 ° C to temperatures of at least 30 ° C, at least 35 ° C or at least 40 ° C, as with increasing temperature, the solubility of organic compounds / residues is improved and thus small or short recording distances for the introduction of the ozone into the solution and / or high ozone concentrations are made possible. Increased temperatures thus offer a high degree of contamination with metal contamination and / or short treatment times. That is, in the ozone-based treatment, the ozone may be dissolved in or part of an aqueous solution, so that wetting the semiconductor substrate with the aqueous solution causes the aqueous solution to react with the semiconductor substrate (s) thereon. In addition to the form in the dissolved state, ozone can also occur in the form of elementary gas bubbles in liquid medium. This is the combination of dissolved ozone and gaseous ozone. The ozone gas bubbles in one example can positively affect the flow to the wafer and remove residues more effectively from the surface. The wetting can take place by means of a bath, into which the semiconductor substrate is introduced, and / or by means of spraying.

The ozone-based treatment is particularly advantageous combined with the cleansing of the organic matter. Such a method may thus also be referred to as a method for treating etched surfaces of a semiconductor substrate using ozone-containing medium. Thus, the embodiments described herein and in this context relate to a method and apparatus for treating a textured silicon substrate, and more particularly to a method of cleaning using an ozone-containing medium. It is compared to the prior art, not focused on the rinse, but on a separate step using the ozone-containing medium, in which the corresponding and to be removed substances are removed by the ozone. This means that the ozone interacts with the semiconductor substrate or the residues.

If the method 100 is configured to include step 110, then it may be performed prior to ozone-based processing 130 and performed to obtain the textured silicon substrate. As already explained above, the ozone-based treatment with hydrofluoric acid and / or hydrogen chloride can be carried out. Again, etching may include at least one of metal assisted chemical etching, electrochemical etching, acidic isotropic texture etching, and acid isotropic texture etching with organic and / or inorganic additives. The etching may alternatively or additionally include edge chemical isolation and / or surface smoothening and / or selective emitter removal and / or a saw damage removal and / or a one-sided treatment or two-sided treatment.

Subsequent to the step 130, in an optional step 140, a renewed rinsing process can be carried out. The step may be the same as or similar to the same or similar rinse steps 120 and / or 1020. Like the other rinse steps, rinse may be performed in step 140 in a temperature range of 5 ° C to 90 ° C.

Subsequently, the method 100 includes the optional step 150, in which the drying of the semiconductor substrate takes place. The drying can be carried out in a temperature range of at least 0 ° C, d. h., A state in which water is liquid, to allow evaporation of the raw material water. A temperature range of at least 25 ° C and at most 100 ° C is preferred. The temperature may be constant or variable over a course of step 150. For example, a variable temperature profile with increasing temperature can help to minimize material stress in the semiconductor substrate. At low temperatures or small temperature differences can be dispensed with such a step of T emperaturanpassung. Step 150 may be performed in the medium of air. Alternatively or additionally, instead of air or in addition to the air, an inert gas may be arranged. Step 150 may also be carried out using an IPA dryer (IPA = isopropyl alcohol). Alternatively or additionally, it is also possible to use a hot air which, for example, conducts a stream of nitrogen over the semiconductor substrate.

Step 140 may be performed after the ozone-based treatment and before drying in step 150 or before the end of the process. The end of the process may include depositing the semiconductor substrate, which may also be understood as drying, for example in ambient air. Step 140 may include wetting the semiconductor substrate with a medium comprising at least one of water, ozone, hydrofluoric acid, and / or hydrogen chloride. A possible ozone concentration is in the range of 1 ppm to 5 ppm or less. The time at which the semiconductor substrate comes in contact with ozone in step 140 and / or the concentration of the same is designed to clean off any residues of the media used in previous steps, while in step 130 treatment of the substrate itself Ozone takes place. The method may be adapted based on different adjustment parameters and / or materials used such that the ozone-based treatment is configured to effect one or more of the alkaline post-cleaning, the removal of porous silicon, the metal cleaning, and the removal of organic compounds. For example. For example, adding components, ingredients or additives to the cleaning medium may cause different settings. According to one embodiment, all three cleaning steps can be obtained in a common pool under at least approximately constant conditions. A purification of organic impurities can be carried out particularly effective at higher temperatures and higher ozone concentrations and can - in itself - be carried out only with ozone and water. An additional removal of porous silicon can be obtained by adding hydrofluoric acid. It is known to perform a metal cleaning only with HF / HCl. Use of a combination of hydrofluoric acid, hydrogen chloride and ozone and / or a combination of hydrofluoric acid and ozone allows the simultaneous export of all three steps, removal of organics, metal residues and porous silicon.

FIG. 2 shows a schematic flow diagram of a method 200 according to one exemplary embodiment. Compared to method 100, method 200 includes an optional step of cleaning 260 organic compounds. Although step 260 is illustrated as being performed prior to step 130, it may alternatively be performed subsequently or simultaneously. Cleaning to remove organic compounds enables a clean surface to be obtained and hence high quality products.

Although alkaline post-cleaning or acid post-cleaning, which may be carried out in addition to the ozone-based treatment, can remove some residues of the etching, in particular porous silicon and metal impurities, other impurities may be left behind. In methods according to embodiments, therefore, cleaning of the surface of the textured silicon substrate to remove organic compounds is performed. The cleaning can be carried out as a separate step or advantageously combinatorially in the ozone-based treatment. The organic compounds are located on the surface of the textured silicon substrate and may be, for example, residues of the etching process and / or the contact of the semiconductor substrate with other substances and / or persons. By cleaning the surface of the organic compounds becomes a highly clean obtained textured surface, which can be det ^¬ USAGE for high quality processed products, such as solar cells.

Step 260 includes cleaning the surface of the textured silicon substrate to effect removal of organic compounds present on the surface of the textured silicon substrate. Step 260 may further be performed to remove porous silicon at the surface of the textured silicon substrate and to perform metal cleaning of the surface of the textured silicon substrate, and thus as an integral step with step 130. Otherwise, the cleaning 260, the step 130 comprising removing porous silicon and / or performing the metal cleaning may also be performed in at least partially separate steps. This means that at least two of the three purification steps can also be carried out in a common step or, as shown in FIG. 3, all three purification steps can be carried out in a common step 310.

3 shows a schematic flow diagram of a method 300 according to an exemplary embodiment, which comprises a step 310, in which the cleaning from the step 260, the removal of the porous silicon, and the metal cleaning are carried out simultaneously by means of the ozone-based treatment, approximately the same as the step 130 ,

It will now be explained how, for example, step 260 can be carried out. The cleaning in the step 260 for removing the organic compounds can be carried out wholly or partly by contacting the silicon substrate with an oxidative component. Exemplary oxidative components are, for example, hydrogen peroxide (H2O2) or ozone (O3). Alternatively or additionally, the silicon substrate may also be associated with an alkaline component, for example potassium hydroxide (KOH). Alternatively or additionally, a RCA (Radio Cooperation of America) cleaning can be carried out, which includes a wet chemical cleaning process. RCA cleaning may include cleaning the semiconductor substrate in two baths. A first bath may include an aqueous solution of ammonium hydroxide and hydrogen peroxide. A second bath into which the semiconductor substrate is subsequently added may include an aqueous solution of hydrochloric acid and hydrogen peroxide. The cleaning 260 may be performed at room temperature, but may be carried out in other temperature ranges. By using a slightly higher temperature range, for example, in a range between 40 ° C and 70 ° C, a high purification efficiency can be obtained. That means cleaning in a bath can be done, such as in a so-called batch process. The method may also include a plurality of baths into which the respective semiconductor substrate is successively brought. Alternatively, at least one bath can be replaced by wetting with the liquid to be applied, for example by using spray nozzles.

A sequence of the individual cleaning steps carried out for the removal of the porous silicon by a known alkaline post-cleaning or the ozone-based treatment and / or the metal cleaning by a known acid post-cleaning or the ozone-based treatment and / or the cleaning by the ozone-based treatment is arbitrary. That is, unlike in FIG. 2, step 130 and then step 260 may be executed first as well. The alkaline post-purification can be obtained, for example, by exports of step 1030. The acid post-purification may be carried out, for example, by performing step 1040.

Alternatively, to obtain the purification of all three components, the organic compounds, the porous silicon, and the metal impurities, ozone may also be used by performing step 130. By using ozone, it becomes possible to combine the purification steps with each other to carry out at least two of the purification steps in a common step.

In the present case, it has been recognized that ozone can be removed to remove porous silicon and / or perform metal cleaning and / or cleaning of the organic compounds by treating the surface of the textured silicon substrate with the ozone-based treatment.

FIG. 4 schematically illustrates an example of an apparatus 40 for performing a method according to the present disclosure. The apparatus 40 includes process media supply means for providing media for cleaning, alkaline post-cleaning, and acid post-cleaning of the surface. The apparatus 40 further includes a substrate handling device configured to position the substrate 82. For example, the substrate 82 may be a wafer. More specifically, the process media delivery device may be configured to include rollers 86 that permit transport and wetting of the substrate 82 with an acidic or alkaline and / or ozone containing medium. For example. at least one of the rollers 86 having a cavity for receiving the medium and be formed so that the medium can pass through a lateral surface through to the substrate, for example. Over a porous surface of the roll. Alternatively or additionally, the process media supply device may comprise a media pool in which the acidic or alkaline and / or ozone-containing medium is located. It is understood that the apparatus 40 may include a plurality of rollers and / or media basins for communicating the substrate 82 with different media. Alternatively, the roller and / or the basin between individual steps can be emptied, optionally cleaned and refilled.

The substrate handling device has rollers 86 over which the substrate 82 is transported. The rollers 86 may represent a horizontal transport system, which means that there may be functional integration between the process media supply device and the substrate handling device. The rollers 86 may function to transport the media to the underside of the substrate 82. For example, the rollers 86 may for this purpose be at least partially disposed in the medium and have a porous or spongy surface or provide the medium from an inner hollow body. Thereby, the underside of the substrate 82 can be wetted with the medium and thus treated.

5 shows an alternative example of an apparatus 50 for carrying out a method according to the present disclosure, in which the substrate handling device is in turn implemented as a horizontal transport system with rollers 86, over which the substrate 82 is transported. The device 50 may be similar to the device described in DE 10 2009 060 931 A1 or WO 201 1/076920 A1, so that, for example, the device 50 for treating silicon wafers 82 is shown as silicon substrates, namely in the direction of passage of these silicon wafers. Wafer 82. They lie along a horizontal transport path, which is formed by transport rollers 86 on transport shafts 87. Several silicon wafers can be driven side by side through the plant 50 and many behind each other at a small distance. Above the transport path along which the substrate 82 is moved, the process media supply device may comprise a still tube 94 provided as a wetting device, which has a distance of a few centimeters to the top of the substrates 82, such as silicon wafers, and over the entire width of the transport path enough. The surge pipe 94 or more still pipes 94 in a row cover the transport path in length. The distance of Schwallrohre 94 may for example be about 15 cm, but possibly also a little more or a little less or change in the course of the transport path.

Furthermore, at the Schwalirohr 94 a post-metering 98 may be provided for replenishing additive as a separate connection. Here, an additive mentioned at the beginning or several of them can be added or metered into the etching solution 85. This can be done so shortly before the application of the etching solution 85 from the stilling tube 94, that evaporation of the aforementioned volatile additives is kept very low or can be completely avoided.

The surge pipe 94 has on its underside a plurality of surge nozzles 96, which may be formed as simple holes, openings or slots. Through them, the medium or the etching solution 85 can emerge and come on the top of the silicon wafer 82 and distribute there, as shown. In contrast to the alkaline etching solution described in DE 10 2009 060 931 A1, another, for example, acidic etching solution may be used, as described, for example, in DE 10 2007 063 202 A1, in which cleaning is additionally carried out. A method described there can be carried out in two steps. Both steps can use acid etching solutions. In the first step, focusing on the texture of the top, and in the second step on a polish from the bottom. Between the steps a rinsing with water can take place.

According to one embodiment, alternatively or in addition to the surge nozzles 96, the process media delivery device may include lower spray nozzles and upper spray nozzles to provide the media from both sides relative to the substrate 82 to treat both major surfaces of the wafer 82. Alternatively, spray nozzles may be provided only on one side. Although five nozzles 96 are shown in FIG. 5, a different number, e.g. B. only one nozzle or a higher number, such as two, three, four, six, ten or more, may be provided.

6 shows an alternative example of an apparatus 60 for performing a method in accordance with the present disclosure, in which the process media provider includes a process media bath 122 in which the media 84, such as an acidic media, is located. A substrate handling device 124, which is only shown very schematically in FIG. 6, is designed to move the substrate 82 into the medium 84, for example, in a horizontal orientation (left-hand part of FIG. 6) or in a vertical orientation (right-hand part of FIG. 6) immerse. The substrate handling device 124 may for this purpose include suitable holders or grippers for simultaneously gripping and dipping substrates into the medium 84, one or more substrates at a time.

In examples, the substrate handling device may include transport rollers or transport chains described in more detail, which are configured to float one or more substrates over the surface of the media 84 or are configured to enclose one or more substrates immerse the medium 84.

The medium 84 may each be at least one medium of the respective process step described in connection with the methods of the disclosure set forth herein.

Although some aspects of the present disclosure have been described as features associated with a device, it will be understood that such description may also be considered as a description of corresponding method features. Although some aspects of the present disclosure have been described as features associated with a method, it will be understood that such description may be considered as a description of corresponding features of a device and the functionality of the device, respectively.

The examples described above are only illustrative of the principles of the present disclosure. It should be understood that modifications and variations of the arrangements and details described are obvious to those skilled in the art. It is therefore intended that the disclosure be limited only by the appended claims and not by the specific details set forth for the purpose of describing and explaining the examples.

Claims

A method (100; 200; 300) for treating a surface of a textured silicon substrate comprising  ozone-based treating (130; 310) the surface of the textured silicon substrate to remove porous silicon and metal cleaning. The method of claim 1, wherein the ozone-based treatment (130; 310) is further performed to effect purification of the textured silicon substrate from organic compounds. The method of claim 1 or 2, wherein the ozone-based treatment (130; 310) is carried out at an ozone concentration of 31 to 150 ppm in an ozone-containing acidic medium. A method according to any of claims 1 to 3, wherein the ozone-based treatment (130; 310) is carried out together with HF and / or HCl. 5. The method of claim 3, wherein the ozone-based treatment (130; 310) is performed concurrently with HF to simultaneously perform organic compound removal and metal cleaning. A method according to claim 4 or 5, wherein the ozone-based treatment (130; 310) is carried out simultaneously with HCl to simultaneously carry out the removal of organic compounds and porous silicon. A method according to any one of the preceding claims, wherein the ozone-based treatment (130; 310) of the surface of the textured silicon substrate is carried out to effect at least removal of porous silicon, metal cleaning and organic compound cleaning. 8. The method of claim 7, wherein the treating (130; 310) is performed to simultaneously effect removal of porous silicon, metal cleaning, and organic compound purification. The method of any one of claims 1 to 8, wherein the ozone-based treatment (130; 310) is performed in a pH range of 0 to 7. 10. The method according to any one of claims 1 to 9, wherein the ozone-based treatment (130; 310) is carried out in a temperature range of 30 ° C to 80 ° C. 11. The method according to any one of claims 1 to 10, further comprising:  Etching (110) performed prior to the ozone-based treatment (130; 310) to obtain the textured silicon substrate. The method of claim 11, wherein the etching (110) comprises at least one of metal assisted chemical etching, electrochemical etching, acidic isotropic texture etching, or acid isotropic texture etching with organic or inorganic additives. 13. The method of claim 11, wherein the etching comprises chemical edge isolation, surface smoothing, selective emitter removal, saw damage removal, one-sided treatment, or two-sided treatment. 14. The method according to any one of claims 1 to 13, further comprising: Drying (150) performed after ozone-based treatment (130; 310). 15. The method of claim 14, wherein said drying (150) is carried out at a temperature ranging from 25 ° C to 100 ° C. 16. The method according to any one of claims 14 or 15, wherein the drying (150) is carried out at a constant temperature or has a variable temperature profile. 17. The method according to any one of claims 14 to 16, wherein the drying (150) is carried out with ei ^¬ nem medium, wherein the medium comprises at least one of air and / or inert gas. 18. The method according to any one of claims 1 to 17, further comprising at least one: Rinsing (120; 140) performed between etching (10) and ozone-based treatment (130; 310) and / or between ozone-based treatment (130; 310) and drying (150). The method of claim 18, wherein the purging (120; 140) is by means of a medium, wherein the medium comprises at least one of water, ozone or HF. 20. The method of claim 19 wherein, when the purge medium (120; 140) comprises ozone, purge (120; 140) occurs at an ozone concentration of 1 to 5 ppm. 21. The method according to any one of claims 18 to 20, wherein the purging (120; 140) is carried out in a temperature range of 5 ° C to 90 ° C. 22. The method according to any one of claims 1 to 21, further comprising Cleaning (260) the surface of the textured silicon substrate prior to ozonized treatment (130; 310) to effect removal of organic compounds present on the surface of the textured silicon substrate. The method of claim 22, wherein the cleaning (260) of the surface is performed with an oxidative and / or an alkaline component. 24. The method of claim 23, wherein the oxidative component comprises at least one of hydrogen peroxide and ozone and / or the alkaline component Ka ^¬ liumhydroxid comprises. 25. The method of claim 22, wherein cleaning (260) the surface comprises RCA cleaning. 26. The method of claim 25, wherein the RCA purification comprises a two-bath purification, wherein a first bath includes an aqueous solution of ammonium hydroxide and hydrogen peroxide, and wherein a second bath includes an aqueous solution of hydrochloric acid and hydrogen peroxide. 27. The method of claim 22, wherein cleaning the surface causes removal of porous silicon, organic compounds and / or texture additives. 28. A method according to any one of claims 22 to 27, wherein the cleaning (260) of the surface takes place at a temperature in the range of 40 ° C to 70 ° C. The method of any one of claims 21 to 27, further comprising etching (110) performed prior to cleaning (260) the surface. The method of claim 29, wherein the etching (110) comprises at least one of metal assisted chemical etching, electrochemical etching, acid isotropic texture etching, or acid isotropic texture etching with organic or inorganic additives. The method of claim 29, wherein the etching (110) comprises an acidic isotropic texture etch with organic or inorganic additives, and the texture comprises HF, HNO ₃ and an additive or HF, HNO ₃ , H 2 O and at least one additive. 32. The method of claim 31, wherein the etching (110) occurs at a temperature in the range of 40 ° C to 70 ° C. 33. The method according to any one of claims 31 or 32, wherein a duration of the etching (1 10) in the range of 0.5-10 minutes. The method of any one of claims 29 to 33, wherein the etching (110) comprises chemical edge isolation, surface smoothening, selective emitter removal, saw damage removal, unilateral treatment or bilateral treatment. An apparatus for performing a method according to any one of claims 1 to 34, comprising a process media providing means for providing a medium for ozone-based processing and a substrate handling means for positioning the silicon substrate to process the surface. 36. The apparatus of claim 35, wherein the process media supply device has at least one porous roller for transporting and wetting the substrate and / or a process media basin.