CN118254082A

CN118254082A - Method for cleaning semiconductor parts

Info

Publication number: CN118254082A
Application number: CN202211689393.2A
Authority: CN
Inventors: 梁重时; 阿尔曼·阿沃杨; 孙祥
Original assignee: Advanced Micro Fabrication Equipment Inc Shanghai
Current assignee: Advanced Micro Fabrication Equipment Inc Shanghai
Filing date: 2022-12-27
Publication date: 2024-06-28

Abstract

The invention provides a cleaning method of a semiconductor part, which is provided with a first surface and a second surface which are opposite, and a plurality of through holes communicated with the first surface and the second surface, and the cleaning method comprises the following steps: providing a chemical fluid polishing solution, wherein the chemical fluid polishing solution comprises a chemical corrosive and a polishing abrasive; and enabling the chemical fluid polishing solution to pass through the through hole and flow from the second surface to the first surface, and cleaning the inner side wall of the through hole in the process of flowing through the through hole. The cleaning method can remove pollutants in the through hole, and is not easy to damage the inner side wall of the through hole.

Description

Method for cleaning semiconductor parts

Technical Field

The invention relates to the technical field of semiconductors, in particular to a cleaning method of semiconductor parts.

Background

Plasma processing equipment is an essential key device in the production of integrated circuits. As integrated circuit fabrication technology nodes break through towards 3nm technology, the requirements for cleanliness in the reaction chamber of plasma processing equipment are also increasing. Particulate contaminants, organic contaminants, etc. present in the reaction chamber greatly affect the accuracy of wafer processing or cause critical defects on the wafer surface, further affecting the yield of wafer processing.

When the pollutants in the reaction cavity reach a certain degree, the parts in the reaction cavity need to be disassembled and cleaned, so that the service life of the parts is prolonged, and the use cost of equipment is reduced. At present, technicians develop various schemes to solve the problem of cleanliness in the reaction chamber body and prolong the service lives of parts. However, the cleaning effect of the current cleaning methods is not obvious.

How to remove the sediment in the through hole of the semiconductor component and to prolong the service life of the semiconductor component is a technical problem to be solved by the person skilled in the art.

Disclosure of Invention

The invention aims to provide a cleaning method for semiconductor parts, which can effectively remove coating pollutants and reaction byproducts attached to the inside and the surface of a through hole of a semiconductor part (a reaction cavity for plasma processing equipment), prolongs the service life of the semiconductor part, and does not damage the semiconductor part in the cleaning process.

In order to achieve the above object, the present invention provides a cleaning method of a semiconductor component having a first surface and a second surface opposite to each other, the semiconductor component further having a plurality of through holes communicating the first surface and the second surface, the cleaning method comprising:

providing a chemical fluid polishing solution, wherein the chemical fluid polishing solution comprises a chemical corrosive and a polishing abrasive;

And enabling the chemical fluid polishing solution to pass through the through hole and flow from the second surface to the first surface, and cleaning the inner side wall of the through hole in the process of flowing through the through hole.

Optionally, contaminants are attached to the inner side walls of the through holes; the chemical etchant in the chemical fluid polishing solution etches contaminants attached to the inner surface of the through hole, and the polishing abrasive grinds the contaminants on the inner surface of the through hole, and the contaminants are removed under the action of the chemical etchant and the polishing abrasive; the contaminants include: coating contaminants, reaction byproducts, and iron oxide; the coating contaminants include: one or more of rare earth oxides, rare earth fluorides, rare earth oxyfluorides; the reaction by-products include: aluminum fluoride, a fluoropolymer containing carbon.

Optionally, the chemical etchant comprises an organic acid; the polishing abrasive is any one or more of silicon dioxide, cerium oxide and aluminum oxide.

Optionally, the sample feeding pressure of the chemical fluid polishing solution is 1 Mpa-20 Mpa; the temperature of the chemical fluid polishing solution is 10-55 ℃; the cleaning time by the chemical fluid polishing solution is 1 min-100 min.

Optionally, the polishing abrasive has a particle size of 0.01 to 15 microns; in the chemical fluid polishing solution, the mass percentage of polishing abrasive is 20-70%.

Optionally, the chemical fluid polishing solution further comprises: organic base, metal corrosion inhibitor, surfactant; the organic base is used for adjusting the pH value of the chemical fluid polishing liquid, so that the chemical corrosion rate of the chemical fluid polishing liquid is matched with the grinding rate of the polishing abrasive; the metal corrosion inhibitor is used for protecting the semiconductor part substrate from being corroded by the organic acid and the organic base; the surfactant is used for adjusting the viscosity of the chemical fluid polishing solution and improving the dispersibility of the abrasive.

Optionally, the method further comprises the step of, before cleaning the semiconductor component by the chemical fluid polishing solution: the adhesive film is stuck on the first surface or the second surface, and the first surface or the second surface is protected; the adhesive film is provided with a plurality of adhesive film holes, and the adhesive film holes are respectively in one-to-one correspondence with the positions of the through holes of the semiconductor parts.

Optionally, if the semiconductor component has been used in a plasma processing apparatus, at least one of the first surface and the second surface is a contaminated surface exposed to plasma, the contaminated surface has contaminants thereon, no adhesive film is adhered to the contaminated surface, and the chemical fluid polishing solution is further used to remove the contaminants on the contaminated surface.

Optionally, for the used semiconductor component, the cleaning method further comprises: the semiconductor component is driven to rotate around the central axis of the semiconductor component, and the polluted surface is cleaned by the stirred chemical fluid polishing solution; the rotation speed of the semiconductor component is 100-10000 rpm, and the rotation time is 1-30 min.

Optionally, the method further comprises the step of after cleaning the semiconductor components by the chemical fluid polishing solution: and tearing off the adhesive film, soaking and cleaning the semiconductor parts by using the polished cleaning agent under the ultrasonic condition, and removing the chemical fluid polishing solution and the residual pollutants.

Optionally, after the semiconductor component is soaked and cleaned by the cleaning agent after polishing, the method further comprises the steps of: the semiconductor parts are cleaned in a clean room using ultra-pure water under megasonic conditions to remove particles less than 0.1 microns remaining on the semiconductor parts.

Optionally, the semiconductor parts after being cleaned by the ultrapure water are dried by using high-purity nitrogen, and are heated and dried by using an oven to remove the residual moisture on the semiconductor parts.

Optionally, the adhesive film is a pressure sensitive film.

Optionally, the temperature of the cleaning agent after polishing is 30-80 ℃; the frequency of the ultrasonic wave is 28 KHz-192 KHz, and the energy density is 0.5W/cm ²～5W/cm²; the cleaning time of the cleaning agent after polishing under the ultrasonic condition is 10 min-60 min.

Optionally, the frequency of the megasonic wave is 850 KHz-1000 KHz, and the cleaning time of the ultra-pure water under the megasonic wave condition is 5 min-30 min.

Alternatively, the purity of the high purity nitrogen gas is 5N or 6N.

Optionally, the temperature of the oven is 60-200 ℃, and the drying time is 1-6 h.

Optionally, the semiconductor component includes: at least one of a gas showerhead, an electrostatic chuck (ESC), a mounting substrate (installation substrate), an inner liner, a gas line (GAS PIPELINE); the through holes are gas channels in the mounting substrate, the gas spray header or the base; or the through hole is: cooling fluid passages in the mounting substrate or susceptor.

Optionally, the polishing abrasive has a mohs hardness greater than the mohs hardness of the contaminant and less than the mohs hardness of the semiconductor component substrate; or the difference between the Mohs hardness of the polishing abrasive and the Mohs hardness of the contaminant is smaller than a set threshold value, and the Mohs hardness of the polishing abrasive is smaller than the Mohs hardness of the semiconductor component substrate.

Compared with the prior art, the technical scheme of the invention has at least the following beneficial effects:

1) Some semiconductor components with through holes are generally used in the reaction chamber of the plasma processing apparatus. In order to improve corrosion resistance, an anti-corrosion coating is formed on the outer surface of the semiconductor component before the semiconductor component is put into use, and the anti-corrosion coating is inevitably formed on the inner surface of the through-hole due to the manufacturing process (CVD, PVD). The invention corrodes through chemical corrosive and grinds the coating pollutant on the inner surface of the through hole through polishing abrasive, so that the coating pollutant on the inner surface of the through hole is removed under the combined action of the chemical corrosive and the polishing abrasive. The invention solves the technical problem that the coating pollutants adhered in the through holes cannot be effectively removed in the prior art, and can prevent the coating pollutants in the through holes from falling into the reaction cavity to form pollution particles after the plasma processing equipment runs for a period of time. The cleaning method of the invention greatly improves the yield of wafer processing.

2) The cleaning method of the invention can effectively remove the coating pollutant on the inner surface of the through hole and the reaction byproducts deposited on the outer surface of the semiconductor part and the inner surface of the through hole in the process and the particles falling off or about to fall off from the surface of the semiconductor part due to the bombardment of the plasmas. The invention is not only suitable for cleaning unused semiconductor components, but also suitable for cleaning used semiconductor components. The invention can improve the processing yield of the wafer, reduce the cleaning frequency of the semiconductor parts, avoid damaging the semiconductor parts in the cleaning process, greatly prolong the service life of the semiconductor parts and improve the production efficiency of the wafer processing equipment.

3) The cleaning method has the characteristics of high cleaning speed and simple cleaning steps.

Drawings

For a clearer description of the technical solutions of the present invention, the drawings that are needed in the description will be briefly introduced below, it being obvious that the drawings in the following description are one embodiment of the present invention, and that, without inventive effort, other drawings can be obtained by those skilled in the art from these drawings:

FIG. 1 is a schematic diagram of a capacitively-coupled plasma processing apparatus of the present invention;

FIG. 2 is a schematic diagram of an inductively coupled plasma processing apparatus in accordance with the present invention;

FIG. 3 is a flow chart of a method for cleaning semiconductor components in accordance with a first embodiment of the present invention;

FIG. 4 is a schematic view of a clamp for clamping semiconductor components in accordance with one embodiment of the present invention;

FIG. 5 is a schematic view of a clamp for clamping a liner according to another embodiment of the invention;

FIGS. 6A and 6B are views showing the states of the gas holes before and after cleaning the gas shower head in the experiment I of the present invention;

FIG. 6C is a schematic view of the yttria ceramic layer on the first surface after cleaning the gas showerhead in experiment one of the present invention;

FIGS. 7A and 7B are top views of the gas holes before and after cleaning the gas shower head in experiment I of the present invention;

FIG. 8 is a schematic diagram of damage to the yttria ceramic layer on the first surface of the gas showerhead by the diamond abrasive in comparative experiment II of the present invention;

FIG. 9 is a schematic illustration of the presence of coating contaminants in the pores of the cleaned gas showerhead in comparative experiment III of the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be further understood that the term "and/or" as used in the present specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.

As used in this specification and the appended claims, the term "if" may be interpreted as "when..once" or "in response to a determination" or "in response to detection" depending on the context. Similarly, the phrase "if a determination" or "if a [ described condition or event ] is detected" may be interpreted in the context of meaning "upon determination" or "in response to determination" or "upon detection of a [ described condition or event ]" or "in response to detection of a [ described condition or event ]".

In addition, in the description of the present application, the terms "first," "second," "third," etc. are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.

The research finds that: there are three main reasons for particle contamination generated within the reaction chamber of a plasma processing apparatus:

1) In the process, the plasma bombards each part in the reaction chamber to cause the surface layer of part to fall off.

2) For plasma corrosion resistance, the surface of the semiconductor component is usually coated with a corrosion-resistant coating, and if the bonding force between the corrosion-resistant coating and the semiconductor component is insufficient, particulate pollutants are generated. For some parts with through holes, ceramic is deposited not only on the surface of the part but also in the through holes during the formation of the ceramic coating. Because the contact angle between the ceramic deposit and the inner surface of the through hole is nearly parallel, the bonding force between the ceramic coating deposited in the through hole and the inner surface of the through hole is relatively weak, and especially, ceramic particle pollutants are easy to fall off after the equipment is operated for a period of time.

3) In the process, many byproducts, such as polymer contaminants with complex structures, are generated as the process gases react with different dielectric layers on the wafer surface. Some of these polymer contaminants are pumped out of the reaction chamber by molecular pumps or dry pumps, but some remain in the reaction chamber, may collect on the chamber walls, may deposit on the surfaces of the components, and may deposit in the through holes of the components, and these polymer contaminants may come off at any time to contaminate the wafer.

The technical scheme of the invention is used for removing the particle pollutants, and is as follows in detail:

Fig. 1 shows a capacitively-coupled plasma processing apparatus, such as the plasma processing apparatus shown in fig. 1, having a vacuum reaction chamber 10, the reaction chamber 10 being enclosed by a generally cylindrical reaction chamber sidewall 101 (typically made of a metallic material).

As shown in fig. 1, a mounting substrate 102 is provided on top of the reaction chamber, and a gas shower head 103 is mounted below the mounting substrate 102. The inside of the mounting substrate 102 is provided with a uniform air chamber 1021, which is connected to a gas supply device 110 through a gas line 104. A cooling fluid passage (not shown) is also provided in the interior of the mounting substrate 102 for conditioning the gas shower head 103. The gas showerhead 103 (typically of aluminum) has opposing first and second surfaces (fixedly attached to the bottom surface of the mounting substrate 102). A plurality of through holes which are communicated with the first surface and the second surface are also formed in the gas spray header, and the through holes are used as the air holes 1031 of the gas spray header 103. The reaction gas in the uniform gas chamber 1021 is uniformly supplied into the reaction chamber through the gas holes 1031.

As shown in fig. 1, an electrostatic chuck is disposed below the gas shower head 103 for carrying a wafer W to be processed. The electrostatic chuck comprises a base 105 (typically of a thermally conductive material such as aluminum) and a dielectric layer 106 (having electrodes 1061 disposed therein for generating electrostatic forces). The base 105 and the dielectric layer 106 are provided with a plurality of through holes, and the through holes on the base 105 and the corresponding through holes on the dielectric layer 106 form channels in the vertical direction. Some of the channels are configured to receive vertically disposed lift pins 108 (for lifting the wafer to effect separation of the wafer from the surface of the electrostatic chuck), referred to as lift pin channels; some of the channels are used to blow helium gas (for adjusting the wafer temperature) to the back side of the wafer, i.e., the gas channels 107 in fig. 1, the gas channels 107 are used to deliver a heat transfer gas to the back side of the wafer, the heat transfer gas comprising helium gas. The base is also provided with a cooling fluid channel 109 inside for tempering the base.

The gas shower head 103 serves as an upper electrode of the reaction chamber 10, and the susceptor 105 serves as a lower electrode of the reaction chamber 10. A radio frequency power is applied to the upper electrode and/or the lower electrode to generate a large electric field inside the reaction chamber. Most of the electric field is contained in the processing region a between the upper electrode and the lower electrode, and this electric field accelerates a small amount of electrons existing inside the reaction chamber so as to collide with gas molecules of the inputted reaction gas. These collisions result in ionization of the reactant gases and excitation of the plasma, thereby generating a plasma within the reaction chamber. Neutral gas molecules of the reactant gas lose electrons when subjected to these strong electric fields, leaving positively charged ions. Positively charged ions are accelerated toward the lower electrode and combine with neutral species in the wafer W being processed to excite wafer W processing, i.e., etching, deposition, etc.

When the outer surfaces of the semiconductor components such as the base 105, the mounting substrate 102 and the gas shower head 103 form corrosion-resistant ceramic coatings, ceramics can be deposited into through holes of the semiconductor components, and the technical scheme of the invention can be used for removing the ceramic coatings in the through holes of the components. The invention can also be used for cleaning coating pollutants in the gas pipeline 104, the uniform gas cavity 1021 of the mounting substrate 102, the gas holes 1031 of the gas spray head 103, the gas channel 107 of the base 105 and the lifting thimble channel, and can also be used for cleaning water rust (ferric oxide) in the cooling liquid channels of the mounting substrate 102 and the base 105.

Fig. 2 shows an inductively coupled plasma processing apparatus having a vacuum reaction chamber 20 enclosed by a generally cylindrical reaction chamber sidewall 201. A liner 220 is disposed within the chamber to protect the interior walls of the chamber from plasma. The inner surface of liner 220 is also typically provided with a corrosion resistant ceramic coating. The liner top has an outwardly extending horizontally extending rim 221, with support provided to the rim 221 by the top surface of the reaction chamber sidewall 201. The rim 221 has opposite first (inner) and second (outer) surfaces, and a plurality of through holes (as gas injection ports 203) communicating the first and second surfaces are formed therein. The reaction gas is delivered to the inside of the reaction chamber through the gas injection port 203. An insulating window 217 is disposed over the chamber sidewall 201, an inductive coupling coil 215 is disposed over the insulating window 217, and a radio frequency power source 218 applies a radio frequency voltage to the inductive coupling coil 215 through a radio frequency matching network 216. The inductive coupling coil 215 generates an inductive magnetic field under the excitation of the radio frequency source 218, and the reaction gas in the reaction chamber generates plasma under the action of the inductive magnetic field.

The cleaning method of the present invention may also be used to clean coating contaminants in the gas injection ports 203 of the liner 220, the gas passages of the susceptor 205, and the lift pin passages, as well as to clean water rust (iron oxide) in the coolant passages 209 of the susceptor 205.

The invention can effectively remove pollutants in the through holes of the semiconductor parts on the premise of not damaging the semiconductor parts, improves the wafer yield, greatly prolongs the service life of the semiconductor parts and reduces the production cost of enterprises. The invention can remove the pollutants in the through holes of the semiconductor parts and effectively remove the pollutants on the surfaces of the semiconductor parts, thereby improving the cleaning efficiency of the semiconductor parts.

Example 1

The semiconductor component to be cleaned has opposite first and second surfaces and is further provided with a plurality of through holes communicating the first and second surfaces. In one embodiment, the semiconductor component to be cleaned has never been used in a plasma processing apparatus, and contaminants including coating contaminants are attached to the inner surfaces of the through holes of the semiconductor component. In the present invention, the coating contaminants include: one or more of rare earth oxides, rare earth fluorides, rare earth oxyfluorides (e.g., yttria, yttrium fluoride, yttrium oxyfluoride, etc.).

In another embodiment, the semiconductor component to be cleaned has been used in a plasma processing apparatus, and at least one of the outer sidewall, the first surface, and the second surface of the semiconductor component is a contaminated surface exposed to plasma, and contaminants are adhered to both the contaminated surface and the inner surface of the via. Both the contaminated surface and the contaminants within the via include reaction byproducts, particulates dislodged from the surface of the semiconductor component, and coating contaminants dislodged from the inner surface of the via. In the present invention, the reaction by-products include: aluminum fluoride, a fluoropolymer containing carbon. The particles falling off from the surface of the component include: yttrium fluoride, aluminum oxide, and aluminum nitride.

The method for cleaning semiconductor parts, as shown in fig. 3, comprises:

And S1, sticking an adhesive film on the first surface or the second surface of the semiconductor component to protect the first surface or the second surface.

The adhesive film is provided with a plurality of adhesive film holes, and the adhesive film holes are respectively in one-to-one correspondence with the positions of the through holes of the semiconductor parts. If the semiconductor component is used in the plasma processing equipment, the adhesive film is not adhered to the polluted surface.

The adhesive film used in the present invention is a pressure-sensitive film, and the film thickness is preferably 70 μm (this is only an example and not a limitation of the present invention). In the embodiment, an adhesive film of SPV-224S model manufactured by Nito electric engineering is used, which has the advantages of high viscosity and no residual adhesive left after tearing.

S2, fixing the semiconductor parts on the fluid polishing device; providing a chemical fluid polishing solution, wherein the chemical fluid polishing solution contains a chemical corrosive and a polishing abrasive, and the chemical fluid polishing solution passes through the through hole and flows from the second surface to the first surface; and removing the pollutants attached to the semiconductor parts under the combined action of the chemical corrosive and the polishing abrasive.

In one embodiment, the fluid polishing apparatus comprises a clamp as shown in fig. 4, the clamp comprising a first portion 330 and a second portion 340, the first portion 330 and the second portion 340 each having a cylindrical structure with an open end provided with an outwardly extending clamping bead 350. The semiconductor component to be cleaned is disposed between the clamping extension 350 of the first portion 330 and the second portion 340, and the outer edge of the semiconductor component is clamped by the first portion 330 and the second portion 340. The first part has at least one liquid outlet 331 and the second part has at least one liquid inlet 341. The chemical fluid polishing liquid flows into the fixture from the liquid inlet 341, passes through the through hole of the semiconductor component, and flows out from the liquid outlet 331. The semiconductor component shown in fig. 4 is a gas shower head 303, and the jig may be used for holding a susceptor or mounting a substrate.

In another embodiment, the fluid polishing apparatus comprises a clamp as shown in FIG. 5 for clamping the liner. The first portion 430 and the second portion 440 of the clamp are each plate-like in structure, the second portion 440 has at least one liquid outlet 441, and the liner 420 is disposed between the first portion 430 and the second portion 440. The chemical fluid polishing liquid flows into the interior of the liner from the gas injection port 403 of the liner 420 and flows out from the liquid outlet 441.

In an alternative embodiment, the clamp is stainless steel or plastic. The diameter of the jig is 200mm to 800mm, and a suitable jig may be selected according to the size of the semiconductor component to be cleaned.

During the process of flowing through the through hole of the semiconductor component, the chemical corrosive corrodes and softens the pollutants attached to the inner surface of the through hole, and the polishing abrasive grinds the pollutants on the inner surface of the through hole. Contaminants on the inner surface of the through-hole are removed by the combined action of the chemical etchant and the polishing abrasive.

For used semiconductor components, the chemical etchant also erodes, softens contaminants adhering to the contaminated surface as the chemical fluid polishing solution flows into and out of the through-holes, and the polishing abrasive grinds the contaminated surface of the contaminant. Contaminants from the contaminated surface are removed by the combination of the chemical etchant and the polishing abrasive.

In this embodiment, the chemical etchant comprises an organic acid. Taking the example of removal of yttria-containing coating contaminants, the chemical reaction of yttria by etching with organic acids is shown below:

Y₂O₃+6H⁺→2Y³⁺+3H₂O

The yttrium oxide coating is corroded by the organic acid to produce a soft yttrium compound layer, so that a polishing abrasive is convenient to grind, the yttrium compound layer removed by grinding is taken away by chemical fluid polishing liquid, and the process is repeated until pollutants on the inner surface of the through hole are removed. The organic acid used in the present invention is preferably citric acid, tartaric acid, malic acid, or the like. Compared with sulfuric acid, hydrochloric acid and nitric acid, the organic acid has weaker corrosion performance, better corrosion uniformity and easier control of corrosion rate, and meanwhile, as the organic acid contains a plurality of hydroxyl groups or carboxyl groups, yttrium metal ions generated after corrosion can be effectively chelated, so that the yttrium metal ions are prevented from remaining on the surface of a semiconductor component.

In one embodiment, the chemical fluid polishing solution further comprises an organic base. The organic base (preferably hydroxylamine, ethanolamine, triethanolamine) is used to adjust the pH of the chemical fluid slurry so that the chemical erosion rate of the chemical fluid slurry matches the grinding rate of the polishing abrasive. When the etching rate is substantially the same as the grinding rate, an optimal cleaning effect can be achieved. In addition, hydroxylamine, ethanolamine and triethanolamine also have better metal ion capturing capability, so that secondary pollution to semiconductor parts caused by metal ion residues after chemical fluid polishing is effectively avoided, and the pressure of a subsequent cleaning process is reduced.

In another embodiment, the chemical fluid polishing solution further comprises a metal corrosion inhibitor. The metal corrosion inhibitor (preferably benzimidazole, sorbitol, 8-hydroxyquinoline) is used for protecting the semiconductor component substrate (aluminum alloy, stainless steel, copper alloy and the like) from being corroded by organic acid and organic alkali, so that irreversible substrate surface damage caused to the semiconductor component is effectively avoided.

In another embodiment, the chemical fluid polishing solution further comprises a surfactant (preferably a polymer, such as polyethylene glycol, polyvinyl alcohol). The surfactant is used for adjusting the viscosity of the chemical fluid polishing solution, so that the chemical corrosive and the polishing abrasive can be well contacted with the pollutants to be removed, and the optimal corrosion effect and grinding effect are achieved. In a preferred embodiment, the chemical fluid polishing solution has a viscosity of 800cps to 10000cps. In addition, the surfactant also has good particle capturing capability, so that secondary pollution to semiconductor parts caused by particle residues after chemical fluid polishing is effectively reduced, and the pressure of a subsequent cleaning process is reduced. In another embodiment, nonionic surfactants such as NP-10, OP-10, lutensol XP60 and the like are used to change the surface properties of the abrasive, so that the chemical fluid polishing liquid has good dispersibility, and the agglomeration of the abrasive can be avoided, thereby improving the polishing effect.

The Mohs hardness of the polishing abrasive is greater than or close to the Mohs hardness of the contaminant (the difference between the Mohs hardness of the polishing abrasive and the Mohs hardness of the contaminant is less than a set threshold), and is less than the Mohs hardness of the semiconductor component, the contaminant is removed without damaging the semiconductor component. In this embodiment, the polishing abrasive is any one or more of silica, ceria, and alumina. The grain diameter of the polishing abrasive is 0.01-15 microns, and the mass percentage of the polishing abrasive in the chemical fluid polishing solution is 20-70%.

In one embodiment, the semiconductor component to be cleaned is a gas showerhead. The gas shower head is typically subjected to an electrolytic treatment to form an anodized aluminum layer on the outer surface of the gas shower head and the inner surfaces of the air holes. Thereafter, the first surface (toward the base) of the gas showerhead is also protected with a corrosion resistant ceramic coating to improve the corrosion resistance of the gas showerhead. The mohs hardness of the anodic aluminum oxide layer on the second surface (connected with the mounting substrate) of the gas spray header is about 7-8, the coating pollutant on the inner surface of the air hole is yttrium oxide (mohs hardness of 6-7), and the polishing abrasive material is aluminum oxide (mohs hardness of 8) or silicon dioxide (mohs hardness of 7). The polishing abrasive can be well prevented from damaging the anodic aluminum oxide layer while the coating pollutants on the inner surfaces of the air holes are effectively removed. Although the test results demonstrate that the polishing abrasive does not damage the anodized aluminum layer, the second surface of the head is typically protected with a film of adhesive so that scratches or indentations on the second surface of the gas showerhead during loading of the gas showerhead into the cleaning apparatus are avoided.

In the embodiment, the sample feeding pressure of the chemical fluid polishing solution is 1 Mpa-20 Mpa; the temperature of the chemical fluid polishing solution is 10-55 ℃; the cleaning time by the chemical fluid polishing solution is 1 min-100 min.

The invention also cleans particles that are to be dislodged from the surface of the semiconductor component by the plasma bombardment.

Some clamps of the fluid polishing apparatus are also capable of driving the semiconductor component to integrally rotate about a central axis of the semiconductor component. In one embodiment, for a used semiconductor part, the cleaning method further comprises: the semiconductor component is driven to rotate about its own central axis, agitates the chemical fluid polishing liquid, and drives the chemical fluid polishing liquid to flow from the second surface to the first surface through the through-hole. Thus, the cleaning effect of the chemical fluid polishing solution on the polluted surface can be further enhanced while the through holes are cleaned. Especially for the semiconductor parts with large cavities, the flow speed and pressure of the chemical fluid polishing solution can be improved in the stirring process, and the cleaning effect on the inner surface of the lining is obviously improved. The semiconductor component can be independently driven to rotate around the central axis of the semiconductor component after the through hole is cleaned by the chemical fluid polishing solution, and the chemical fluid polishing solution is not driven to pass through the through hole at the moment. The rotation speed of the semiconductor component is 100-10000 rpm, and the rotation time is 1-30 min (usually 5 min).

And S3, tearing off the adhesive film, soaking and cleaning the semiconductor parts by using the cleaning agent under the ultrasonic condition after polishing, and removing the chemical fluid polishing solution and residual pollutants.

In this example, the post-polishing cleaning agent was a CMP-B200 cleaning liquid manufactured by Kanto chemical Co., ltd, or a CLEAN 100 cleaning liquid and a CLEAN 8000 cleaning liquid manufactured by Wako pure chemical industries, ltd. This is by way of example only, and any post-polishing cleaning agent capable of removing chemical fluid polishing solutions and residual contaminants is suitable for use in the present invention.

In the embodiment, the temperature of the cleaning agent after polishing is 30-80 ℃; the frequency of the ultrasonic wave is 28 KHz-192 KHz, and the energy density is 0.5W/cm ²～5W/cm²; the cleaning time of the cleaning agent after polishing under the ultrasonic condition is 10 min-60 min.

And S4, cleaning the semiconductor parts in a clean room by using ultrapure water under megasonic conditions to remove particles smaller than 0.1 micron remained on the semiconductor parts.

In the embodiment, the cleanliness Class of the clean room is Class 10 or Class 100, the frequency of the megasonic wave is 850 KHz-1000 KHz, and the cleaning time of the ultra-pure water under the megasonic wave condition is 5 min-30 min.

And S5, drying the semiconductor parts subjected to the ultrapure water cleaning by using high-purity nitrogen, and heating and drying by using an oven to remove residual moisture on the semiconductor parts.

In this embodiment, the purity of the high purity nitrogen gas is 5N or 6N. The temperature of the oven is 60-200 ℃ and the drying time is 1-6 h.

Experimental data

In order to verify the cleaning effect of the present invention, a number of experiments were performed with cleaning of the used gas shower head as an example. The different parameters in each experiment are shown below.

Experiment one used gas shower heads were cleaned using the chemical fluid polishing solution of the present invention.

TABLE 1

In the comparison experiment, hot water is used for replacing the chemical fluid polishing solution, and the used gas spray head is cleaned in a hot water soaking mode.

TABLE 2

And in a second comparison experiment, the chemical fluid polishing solution is replaced by the diamond polishing solution, and the gas spray head is subjected to fluid polishing. The diamond polishing liquid contains the chemical etchant of the invention, but the polishing abrasive is diamond (particle size 1 micron), and the content of the diamond abrasive is 30%. The fluid polishing solution in the third experiment only comprises pure water, silicone oil and polyethylene glycol lubricant, the polishing abrasive is silicon dioxide (particle size 100 nm), and the content of the polishing abrasive is 30%.

TABLE 3 Table 3

The gas shower heads before and after cleaning were characterized using a scanning electron microscope (Scanning Electron Microscope, SEM), an energy dispersive X-ray spectrometer (ENERGY DISPERSIVE X-ray spectrometer, EDX), a surface roughness meter, a film thickness meter, etc., and further the cleaned gas shower heads were mounted on a plasma processing apparatus to test their service lives. The cleaning effect of each experiment is as follows:

TABLE 4 Table 4

From the data in Table 4, the invention can effectively remove the coating pollutant in the gas spray header air hole, the particle pollutant on the outer surface of the gas spray header (the particle matter which is fallen off by the surface of the semiconductor component by the bombardment of the plasma) and the reaction byproducts, and ensure the integrity of the anodic oxide layer in the air hole.

Fig. 6A and 6B show the state of the gas shower head 103 in the gas holes 1031 before and after cleaning, and it is obvious that the coating contaminants 300 in the gas holes 1031 are removed completely after the gas shower head 103 is cleaned, and the anodized aluminum layer in the gas holes 1031 remains intact. It should be noted that the removal is not absolute in the present invention, and the coating contaminant 300 in the air hole 1031 may be considered to be removed when the content thereof is lower than a set threshold.

Since the first clean of the experiment was a used gas showerhead 103, the yttria ceramic layer (mohs hardness of about 6-7) on the first surface was not glued. Fig. 6C shows that in experiment one, the yttria ceramic layer on the first surface was less scratched and in good condition after the gas shower head 103 was cleaned. The mohs hardness of the anodized aluminum layer (7-8 mohs hardness) on the second surface of the gas showerhead is higher than the mohs hardness of the silica abrasive (7 mohs hardness), which hardly damages the anodized aluminum layer.

In the first experiment, the top view of the gas holes 1031 before and after cleaning the gas shower head 103 is shown in fig. 7A and 7B, and the result shows that the pore diameter of the cleaned gas holes is increased, the edge of the pore wall is smooth, and the removal of the coating contaminants 300 deposited on the pore opening is described again.

Further, EDX results showed that the fluoride content of the post-cleaning gas showerhead surface was reduced from 3.64wt.% to 0wt.% prior to cleaning in experiment one, indicating that both particulate contaminants (e.g., yttrium fluoride, aluminum fluoride) and reaction byproducts (e.g., carbon-containing fluoropolymers) on the gas showerhead surface were removed.

Comparative experiment one as a blank, hot water was used instead of chemical fluid polishing solution. In the first comparison experiment, the coating pollutants in the air holes, the particle pollutants on the surface of the gas spray head and the reaction byproducts cannot be removed, and the gas spray head cannot be used any more.

The second experiment adopts a polishing abrasive (Mohs hardness 10) of diamond particles to grind the coating pollutants in the air holes of the gas spray header, and the result shows that the coating pollutants in the air holes are better removed. However, the hardness of the diamond abrasive is larger than that of the anodized aluminum, and the anodized aluminum layer and the yttrium oxide ceramic layer on the outer surface of the gas spray header are seriously damaged when polishing the anodized aluminum layer in the air hole. Therefore, in the second comparison experiment, the service life of the cleaned gas spray header is obviously lower. Fig. 8 is a schematic diagram of damage to the yttria ceramic layer on the first surface of the gas showerhead in comparative experiment two.

Comparative experiment three used a silica abrasive, but the fluid slurry did not contain a chemical etchant, as shown in fig. 9, and after cleaning, the inner walls of the pores 1031 still had a small amount of coating contaminants 300.

In summary, the chemical fluid polishing solution can remove pollutants in the through holes of the semiconductor parts, almost has no damage to the base material of the semiconductor parts, and can effectively recycle the semiconductor parts after cleaning.

It should be understood that the sequence number of each step in the foregoing embodiment does not mean that the execution sequence of each process should be determined by the function and the internal logic, and should not limit the implementation process of the embodiment of the present application.

While the invention has been described with reference to certain preferred embodiments, it will be understood by those skilled in the art that various changes and substitutions of equivalents may be made and equivalents will be apparent to those skilled in the art without departing from the scope of the invention. Therefore, the protection scope of the invention is subject to the protection scope of the claims.

Claims

1. A method of cleaning a semiconductor component having opposing first and second surfaces, the semiconductor component further having a plurality of through holes communicating the first and second surfaces, comprising:

2. The method for cleaning a semiconductor component as claimed in claim 1, wherein contaminants are attached to an inner side wall of the through hole; the chemical etchant in the chemical fluid polishing solution etches contaminants attached to the inner surface of the through hole, and the polishing abrasive grinds the contaminants on the inner surface of the through hole, and the contaminants are removed under the action of the chemical etchant and the polishing abrasive; the contaminants include: coating contaminants, reaction byproducts, and iron oxide; the coating contaminants include: one or more of rare earth oxides, rare earth fluorides, rare earth oxyfluorides; the reaction by-products include: aluminum fluoride, a fluoropolymer containing carbon.

3. The method of cleaning a semiconductor component as recited in claim 2, wherein the chemical etchant contains an organic acid; the polishing abrasive is any one or more of silicon dioxide, cerium oxide and aluminum oxide.

4. The method for cleaning a semiconductor component as defined in claim 1, wherein the sample-feeding pressure of the chemical fluid polishing liquid is 1Mpa to 20Mpa; the temperature of the chemical fluid polishing solution is 10-55 ℃; the cleaning time by the chemical fluid polishing solution is 1 min-100 min.

5. The method for cleaning a semiconductor component as claimed in claim 1, wherein the polishing abrasive has a particle size of 0.01 μm to 15 μm; in the chemical fluid polishing solution, the mass percentage of polishing abrasive is 20-70%.

6. The method of cleaning a semiconductor component as recited in claim 3, wherein the chemical fluid polishing solution further comprises: organic base, metal corrosion inhibitor, surfactant; the organic base is used for adjusting the pH value of the chemical fluid polishing liquid, so that the chemical corrosion rate of the chemical fluid polishing liquid is matched with the grinding rate of the polishing abrasive; the metal corrosion inhibitor is used for protecting the semiconductor part substrate from being corroded by the organic acid and the organic base; the surfactant is used for adjusting the viscosity of the chemical fluid polishing solution and improving the dispersibility of the abrasive.

7. The method for cleaning semiconductor parts according to claim 1, further comprising the step of, before cleaning the semiconductor parts with the chemical fluid polishing liquid: the adhesive film is stuck on the first surface or the second surface, and the first surface or the second surface is protected; the adhesive film is provided with a plurality of adhesive film holes, and the adhesive film holes are respectively in one-to-one correspondence with the positions of the through holes of the semiconductor parts.

8. The method of cleaning a semiconductor component as recited in claim 7, wherein if the semiconductor component has been used in a plasma processing apparatus, at least one of the first surface and the second surface is a contaminated surface exposed to a plasma, the contaminated surface has contaminants thereon, the chemical fluid polishing solution is not applied to the contaminated surface, and the chemical fluid polishing solution is further used to remove the contaminants on the contaminated surface.

9. The method of cleaning semiconductor parts according to claim 8, wherein for used semiconductor parts, the method further comprises: the semiconductor component is driven to rotate around the central axis of the semiconductor component, and the polluted surface is cleaned by the stirred chemical fluid polishing solution; the rotation speed of the semiconductor component is 100-10000 rpm, and the rotation time is 1-30 min.

10. The method of cleaning semiconductor parts according to claim 7, further comprising the step of, after cleaning the semiconductor parts with the chemical fluid polishing liquid: and tearing off the adhesive film, soaking and cleaning the semiconductor parts by using the polished cleaning agent under the ultrasonic condition, and removing the chemical fluid polishing solution and the residual pollutants.

11. The method of cleaning a semiconductor component as defined in claim 10, further comprising the step of, after immersing and cleaning the semiconductor component with the post-polishing cleaning agent: the semiconductor parts are cleaned in a clean room using ultra-pure water under megasonic conditions to remove particles less than 0.1 microns remaining on the semiconductor parts.

12. The method for cleaning a semiconductor component as defined in claim 11, wherein the semiconductor component after the ultrapure water cleaning is blow-dried with high-purity nitrogen gas, and the semiconductor component is heat-dried with an oven to remove moisture remaining on the semiconductor component.

13. The method for cleaning a semiconductor component as claimed in claim 7, wherein the adhesive film is a pressure-sensitive film.

14. The method for cleaning a semiconductor component according to claim 10, wherein the temperature of the cleaning agent after polishing is 30 ℃ to 80 ℃; the frequency of the ultrasonic wave is 28 KHz-192 KHz, and the energy density is 0.5W/cm ²～5W/cm²; the cleaning time of the cleaning agent after polishing under the ultrasonic condition is 10 min-60 min.

15. The method for cleaning a semiconductor component as claimed in claim 11, wherein the megasonic wave has a frequency of 850KHz to 1000KHz and the cleaning time by ultra-pure water under megasonic wave conditions is 5min to 30min.

16. The method for cleaning semiconductor parts according to claim 12, wherein the purity of the high purity nitrogen gas is 5N or 6N.

17. The method for cleaning semiconductor parts according to claim 12, wherein the temperature of the oven is 60 ℃ to 200 ℃ and the drying time is 1h to 6h.

18. The method of cleaning a semiconductor component as claimed in claim 1, wherein the semiconductor component comprises: at least one of a gas showerhead, an electrostatic chuck, a mounting substrate, a liner, and a gas line; the through holes are gas channels in the mounting substrate, the gas spray header or the base; or the through hole is: cooling fluid passages in the mounting substrate or susceptor.

19. The method of cleaning a semiconductor component according to claim 2, wherein the polishing abrasive has a mohs hardness greater than the mohs hardness of the contaminant and less than the mohs hardness of the semiconductor component substrate; or the difference between the Mohs hardness of the polishing abrasive and the Mohs hardness of the contaminant is smaller than a set threshold value, and the Mohs hardness of the polishing abrasive is smaller than the Mohs hardness of the semiconductor component substrate.