CN116387137A - Cleaning method for efficiently removing silicon carbide substrate wafer pollution - Google Patents
Cleaning method for efficiently removing silicon carbide substrate wafer pollution Download PDFInfo
- Publication number
- CN116387137A CN116387137A CN202310012004.0A CN202310012004A CN116387137A CN 116387137 A CN116387137 A CN 116387137A CN 202310012004 A CN202310012004 A CN 202310012004A CN 116387137 A CN116387137 A CN 116387137A
- Authority
- CN
- China
- Prior art keywords
- silicon carbide
- carbide substrate
- substrate wafer
- cleaning
- pure water
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 title claims abstract description 124
- 229910010271 silicon carbide Inorganic materials 0.000 title claims abstract description 124
- 239000000758 substrate Substances 0.000 title claims abstract description 122
- 238000004140 cleaning Methods 0.000 title claims abstract description 78
- 238000000034 method Methods 0.000 title claims abstract description 40
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 59
- 239000007788 liquid Substances 0.000 claims abstract description 44
- 239000003814 drug Substances 0.000 claims abstract description 34
- 238000002791 soaking Methods 0.000 claims abstract description 34
- 235000011114 ammonium hydroxide Nutrition 0.000 claims abstract description 33
- 238000004506 ultrasonic cleaning Methods 0.000 claims abstract description 28
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 24
- 238000001035 drying Methods 0.000 claims abstract description 24
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims abstract description 21
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims abstract description 14
- 239000008367 deionised water Substances 0.000 claims abstract description 11
- 229910021641 deionized water Inorganic materials 0.000 claims abstract description 11
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 11
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Substances OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims abstract description 8
- 238000010926 purge Methods 0.000 claims abstract description 6
- 235000012431 wafers Nutrition 0.000 claims description 134
- 239000002245 particle Substances 0.000 claims description 13
- 238000011109 contamination Methods 0.000 claims description 11
- 230000005540 biological transmission Effects 0.000 claims description 10
- 239000002253 acid Substances 0.000 claims description 5
- 238000006243 chemical reaction Methods 0.000 claims description 5
- 239000012530 fluid Substances 0.000 claims description 5
- 238000011010 flushing procedure Methods 0.000 claims description 5
- 238000005406 washing Methods 0.000 claims description 5
- 239000000126 substance Substances 0.000 claims description 4
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 2
- 230000001502 supplementing effect Effects 0.000 claims description 2
- 238000005259 measurement Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 239000004065 semiconductor Substances 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 4
- 239000012535 impurity Substances 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 229910001385 heavy metal Inorganic materials 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 239000003595 mist Substances 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000003749 cleanliness Effects 0.000 description 2
- 150000002484 inorganic compounds Chemical class 0.000 description 2
- 229910010272 inorganic material Inorganic materials 0.000 description 2
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007123 defense Effects 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000005661 hydrophobic surface Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000002923 metal particle Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000005693 optoelectronics Effects 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000002957 persistent organic pollutant Substances 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02041—Cleaning
- H01L21/02043—Cleaning before device manufacture, i.e. Begin-Of-Line process
- H01L21/02052—Wet cleaning only
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Abstract
The invention discloses a cleaning method for efficiently removing silicon carbide substrate wafer pollution, which comprises the following steps: taking the silicon carbide substrate wafer out of the product box and putting the silicon carbide substrate wafer into a corresponding PFA clamping plug; soaking the silicon carbide substrate wafer in SPM liquid medicine, wherein the liquid medicine proportion is as follows: 98% concentrated sulfuric acid: 30% -32% hydrogen peroxide = 3:1 to 7:3; transferring the silicon carbide substrate wafer into a pure water ultrasonic tank, and performing pure water circulation overflow ultrasonic cleaning; transferring the silicon carbide substrate wafer into an ammonia water tank, and soaking with ammonia water liquid medicine in the following ratio: 28% -30% ammonia water solution: deionized water pure water = 2.4:8 to 3.6:9; transferring the silicon carbide substrate wafer into a pure water ultrasonic tank, and performing pure water circulation overflow ultrasonic cleaning; rapidly spin-drying a silicon carbide substrate wafer, and purging with high-purity nitrogen; the invention improves the cleaning quality, and the cleaning degree of the wafer surface reaches a higher level before the epitaxial growth of the substrate.
Description
Technical Field
The invention relates to the technical field of semiconductor cleaning processes, in particular to a cleaning method for efficiently removing silicon carbide substrate wafer pollution.
Background
Silicon carbide is used as a third-generation semiconductor material, has the characteristics of large forbidden bandwidth, high breakdown field strength, high thermal conductivity, high electron saturation drift speed, strong radiation resistance, good chemical stability and the like, and becomes a key material of a new-generation electronic device. The method has the advantages of promoting the growth of trillion markets in the aspects of energy conservation and emission reduction, national defense construction, electronic information and the like. Meanwhile, silicon carbide has very small lattice mismatch and thermal expansion coefficient difference with GaN which is an important material for manufacturing high-power microwave, power electronic and optoelectronic devices, so that the silicon carbide becomes an important substrate material of a new generation of wide-bandgap semiconductor devices.
With the continuous development of silicon carbide semiconductor technology, the requirements on the process technology are higher and higher, in particular to the surface cleaning quality of silicon carbide substrate wafers, and the main reason is that the contamination of particles and metal impurities on the wafer surfaces can seriously affect the quality and the yield of devices. Taking 2-6 inches as an example, cleaning technology in the industry has gradually matured; but still in the exploratory stage for 8 inch cleaning techniques.
As the wafer size increases, so does the cleaning quality requirements of silicon carbide substrate wafers prior to epitaxial growth. At present, the cleaning technology of the semiconductor wafer mainly still adopts wet cleaning, which comprises methods such as solution soaking, mechanical brushing, ultrasonic cleaning, megasonic cleaning, rotary spraying and the like. The difficulty with 8 inch silicon carbide wafer cleaning is that large size silicon carbide wafers are mechanically difficult to compatible with existing equipment and single wet cleaning does not meet the surface cleanliness requirements.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a cleaning method for efficiently removing silicon carbide substrate wafer pollution; the silicon carbide substrate wafer is not damaged in the cleaning process, new impurities are not introduced to pollute the wafer, and meanwhile, the cleaning quality and the cleaning efficiency are ensured, so that the cleaning degree of the wafer surface reaches a higher level before the epitaxial growth of the substrate.
In order to achieve the above object, the present invention provides a cleaning method for efficiently removing contamination of a silicon carbide substrate wafer, comprising the steps of:
step S1: taking the silicon carbide substrate wafer out of the product box and putting the silicon carbide substrate wafer into a corresponding PFA clamping plug;
step S2: soaking the silicon carbide substrate wafer in SPM liquid medicine, wherein the liquid medicine proportion is as follows: 98% concentrated sulfuric acid (strong acid): 30% -32% hydrogen peroxide (oxide) =3:1 to 7:3;
step S3: transferring the silicon carbide substrate wafer into a pure water ultrasonic tank, and performing pure water circulation overflow ultrasonic cleaning; removing SPM liquid medicine and large-size particles on the surface;
step S4: transferring the silicon carbide substrate wafer into an ammonia water tank, and soaking with ammonia water liquid medicine in the following ratio: 28% -30% ammonia water solution: deionized water pure water = 2.4:8 to 3.6:9;
step S5: transferring the silicon carbide substrate wafer into a pure water ultrasonic tank, and performing pure water circulation overflow ultrasonic cleaning; removing ammonia liquor on the surface;
step S6: and (3) rapidly spin-drying the silicon carbide substrate wafer, wherein the spin-drying process uses high-purity nitrogen for purging.
Preferably, the method further comprises the step of S7: carrying out automatic double-sided cleaning on the spin-dried silicon carbide substrate wafer; the method specifically comprises the following steps:
step S71: fixing a silicon carbide substrate wafer by using a central rotating chuck, and rotating at a high speed; jet-type vaporific cleaning is carried out by adopting two fluids of water and high-purity nitrogen;
step S72: washing the two sides of the silicon carbide substrate wafer with deionized water and 2-4% HF liquid medicine respectively;
step S73: and finally, spin-drying the water on the surface of the silicon carbide substrate wafer through a high rotating speed.
Preferably, in the step S1, at most 25 pieces are put into the corresponding PFA jam.
Preferably, in the step S2, the temperature of the silicon carbide substrate wafer for performing the SPM chemical solution soaking is controlled to be between 110 and 130 ℃, and the soaking treatment time is controlled to be between 15 and 30 minutes.
Preferably, in the step S3 and the step S5, the cycle period of the pure water circulation overflow ultrasonic cleaning is between 2 and 4 times, and the cleaning treatment time is controlled between 5 and 15 minutes.
Preferably, in the step S4, the temperature of the silicon carbide substrate wafer immersed in the ammonia solution is controlled to be between 55 and 75 ℃, and the immersing time is controlled to be between 15 and 30 minutes; the ammonia liquor is subjected to liquor supplementing of 100ml-200ml/h according to the volatilization degree.
Preferably, in the step S6, the spin-drying speed of the silicon carbide substrate wafer is between 800rpm and 1500rpm; the spin-drying time is between 5 and 8 minutes.
Preferably, the ultrasonic cleaning frequency in the step S3 and the step S5 adopts a 40-80KHz frequency conversion mode, the ultrasonic power range is 500-800W, and the ultrasonic transmission mode is longitudinal liquid transmission.
Preferably, in the step S71, the silicon carbide substrate wafer is rotated at a high speed of 800-1200rpm, and the pressure of the water and the high-purity nitrogen gas is 30-50 psi; the cleaning time is between 60 and 80; in the step S72, the cycle period of the flushing is between 2 and 4 times; in the step S73, the rotating speed is increased to 1500-2000rpm, and the moisture on the surface of the silicon carbide substrate wafer is dried through the high rotating speed.
Compared with the prior art, the invention has the beneficial effects that:
according to the invention, SPM liquid medicine and ammonia liquid medicine are used for respectively soaking the silicon carbide substrate wafer, so that organic matters, inorganic compounds and heavy metal ions with strong adsorptivity on the surface of the silicon carbide substrate wafer can be effectively removed, and meanwhile, the surface oxide layer can be removed; ensuring that the cleaning degree of the surface of the wafer reaches a higher level before the epitaxial growth of the substrate; by adopting the cleaning method provided by the invention, the granularity of the surface of the silicon carbide substrate wafer is less than or equal to 30, and the cleaning effect of the wafer is obviously improved; the cleaning efficiency can be obviously improved while the cleaning quality is ensured.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a graph showing the particle size measurement of the surface of a silicon carbide substrate wafer prior to cleaning in example 1 provided by the present invention;
FIG. 2 is a graph showing the particle size measurement of the surface of a silicon carbide substrate wafer cleaned by the prior art cleaning technique according to example 1 provided by the present invention;
FIG. 3 is a graph showing the particle size measurement of the surface of a silicon carbide substrate wafer cleaned by the cleaning technique of the present invention in example 1;
FIG. 4 is a graph showing the particle size measurement of the surface of a silicon carbide substrate wafer prior to cleaning in example 2 provided by the present invention;
FIG. 5 is a graph showing the particle size measurement of the surface of a silicon carbide substrate wafer cleaned by the prior art cleaning technique according to example 2 provided by the present invention;
FIG. 6 is a graph of particle size measurements of the surface of a silicon carbide substrate wafer cleaned using the cleaning technique of the present invention, as provided in example 2.
Detailed Description
The technical solutions of the present embodiment of the present invention will be clearly and completely described below with reference to the drawings in the present embodiment of the present invention, and it is apparent that the described present embodiment is one embodiment of the present invention, but not all the present embodiments. All other embodiments, which can be made by those skilled in the art without making any inventive effort, are intended to be within the scope of the present invention.
The invention provides a cleaning method for efficiently removing silicon carbide substrate wafer pollution, which comprises the following steps:
step S1: taking the silicon carbide substrate wafer out of the product box and putting the silicon carbide substrate wafer into a corresponding PFA clamping plug; in the invention, in the cleaning process, the silicon carbide substrate wafer is loaded by adopting the PFA blocking plug, so that a plurality of wafers can be simultaneously taken and placed, the operation of each process is convenient, and the cleaning efficiency is improved. Preferably, the silicon carbide substrate wafer is removed from the product cassette and placed into a corresponding PFA jam; a maximum of 25 wafers were placed per PFA card.
Step S2: soaking the silicon carbide substrate wafer in SPM liquid medicine, wherein the liquid medicine proportion is as follows: 98% concentrated sulfuric acid (strong acid): 30% -32% hydrogen peroxide (oxide) =3:1 to 7:3; the temperature control range of SPM liquid medicine soaking of the silicon carbide substrate wafer is between 110 and 130 ℃, and the soaking treatment time is between 15 and 30 minutes.
The SPM liquid medicine soaking function is as follows: removing organic matters, inorganic compounds and heavy metal ions such as Hg, ge and the like on the surface of the wafer. The concentrated sulfuric acid can dehydrate and carbonize organic matters, and the hydrogen peroxide can oxidize carbonized products into carbon monoxide or carbon dioxide gas; concentrated sulfuric acid can also dissolve various metal particles and heavy metal ions for combination.
Step S3: transferring the silicon carbide substrate wafer into a pure water ultrasonic tank, and performing pure water circulation overflow ultrasonic cleaning; the cycle period of the pure water circulation overflow ultrasonic cleaning is between 2 and 4 times, and the cleaning treatment time is controlled between 5 and 15 minutes.
The ultrasonic cleaning function is as follows: removing SPM liquid medicine and large-size particles on the surface; the principle is as follows: under the action of ultrasonic wave, the liquid medium will generate a sparse part and a dense part, the sparse part generates a nearly vacuum cavity bubble, and when the cavity bubble disappears, a strong local pressure is generated nearby, so that the chemical bond in the molecule is broken to desorb the impurity on the surface of the wafer.
Step S4: transferring the silicon carbide substrate wafer into an ammonia water tank, and soaking with ammonia water liquid medicine in the following ratio: 28% -30% ammonia water solution: deionized water pure water = 2.4:8 to 3.6:9; the temperature control range of the silicon carbide substrate wafer for soaking with ammonia liquor is between 55 and 75 ℃, and the soaking treatment time is between 15 and 30 minutes.
The ammonia water liquid medicine soaking function is as follows: stripping wafer surface cations and removing surface particles; slight organic pollutants and partial metallized pollutants can also be removed; further, the wafer may experience surface roughness while oxidizing and etching. Therefore, the concentration and temperature of the ammonia water should not be too high, and the liquid replacement of 100ml-200ml/h should be carried out according to the volatilization degree.
Step S5: transferring the silicon carbide substrate wafer into a pure water ultrasonic tank, and performing pure water circulation overflow ultrasonic cleaning; removing ammonia liquor on the surface; the cycle period of the pure water circulation overflow ultrasonic cleaning is between 2 and 4 times, and the cleaning treatment time is controlled between 5 and 15 minutes.
The effect of ultrasonic cleaning again is: removing ammonia liquor and particles on the surface of the wafer.
Furthermore, the ultrasonic cleaning frequency in the step S3 and the step S5 adopts a 40-80KHz frequency conversion mode, the ultrasonic power range is 500-800W, and the ultrasonic transmission mode is longitudinal liquid transmission.
Step S6: rapidly spin-drying a silicon carbide substrate wafer, wherein the spin-drying process is performed by using high-purity nitrogen to purge, and the spin-drying rotating speed of the silicon carbide substrate wafer is between 800 and 1500rpm; the spin-drying time is between 5 and 8 minutes. The inventors have found that in this preferred embodiment, the drying rate is fast and is beneficial for maintaining the cleanliness of the wafer surface.
Step S7: carrying out automatic double-sided cleaning on the spin-dried silicon carbide substrate wafer; the method specifically comprises the following steps:
step S71: fixing a silicon carbide substrate wafer by using a central rotary sucker, and rotating at a high speed, wherein the rotating speed of the silicon carbide substrate wafer is between 800 and 1200rpm, and jet-type mist cleaning is performed by adopting two fluids of water and high-purity nitrogen (the pressure is between 30 and 50 psi);
step S72: washing the two sides of the silicon carbide substrate wafer with deionized water and 2-4% HF liquid medicine respectively; the cycle period of the flushing is between 2 and 4 times;
step S73: the rotational speed is increased to 1500-2000rpm, and the water on the surface of the silicon carbide substrate wafer is dried through the high rotational speed.
The automatic double-sided cleaning function is as follows: the contamination of the wafer surface is dissolved by the sprayed liquid, and the liquid dissolved with impurities is separated from the wafer surface in time by the centrifugal effect of high-speed rotation. The HF liquid medicine is added to remove the oxide layer and form hydrogen bond on the surface of the wafer, so that the subsequent wafer pollution degree is reduced due to the hydrophobic surface.
Example 1
Step S1: and taking out the 25 silicon carbide substrate wafers from the product box, and putting the silicon carbide substrate wafers into corresponding PFA plugs.
Step S2: soaking the silicon carbide substrate wafer in SPM liquid medicine, wherein the liquid medicine proportion is as follows: 98% concentrated sulfuric acid (strong acid): 30% -32% hydrogen peroxide (oxide) =3:1; the temperature of the silicon carbide substrate wafer for soaking with SPM liquid medicine is 110 ℃, and the soaking treatment time is 15min;
step S3: transferring the silicon carbide substrate wafer into a pure water ultrasonic tank, and performing pure water circulation overflow ultrasonic cleaning; the cycle period of the pure water circulation overflow ultrasonic cleaning is 2 times, and the cleaning treatment time is 5min.
Step S4: transferring the silicon carbide substrate wafer into an ammonia water tank, and soaking with ammonia water liquid medicine in the following ratio: 28% -30% ammonia water solution: deionized water pure water = 2.4:8, 8; the temperature of the silicon carbide substrate wafer for soaking with the ammonia liquor is 55 ℃, and the soaking treatment time is 15min.
Step S5: transferring the silicon carbide substrate wafer into a pure water ultrasonic tank, and performing pure water circulation overflow ultrasonic cleaning; removing ammonia liquor on the surface of the silicon carbide substrate wafer; the cycle period of the pure water circulation overflow ultrasonic cleaning is 2 times, and the cleaning treatment time is 5min.
Furthermore, the ultrasonic cleaning frequency in the step S3 and the step S5 adopts a 40-80KHz frequency conversion mode, the ultrasonic power range is 500W, and the ultrasonic transmission mode is longitudinal liquid transmission.
Step S6: rapidly spin-drying a silicon carbide substrate wafer, wherein the spin-drying process is performed by using high-purity nitrogen to purge, and the spin-drying rotating speed of the silicon carbide substrate wafer is 800rpm; the spin-drying time was 5 minutes.
Step S7: carrying out automatic double-sided cleaning on the spin-dried silicon carbide substrate wafer; the method specifically comprises the following steps:
step S71: fixing a silicon carbide substrate wafer by using a central rotary sucker, and rotating at a high speed, wherein the rotating speed of the silicon carbide substrate wafer is 800rpm, and jet-type mist cleaning is performed by adopting two fluids of water and high-purity nitrogen (the pressure is 30 psi);
step S72: washing the two sides of the silicon carbide substrate wafer by deionized water and 2% HF liquid medicine respectively; the cycle period of the flushing is 2 times;
step S73: the rotational speed is increased to 1500rpm, and the moisture on the surface of the silicon carbide substrate wafer is dried by the high rotational speed.
As shown in fig. 1, the surface granularity of the silicon carbide substrate wafer before cleaning in the embodiment 1 is 552; as shown in fig. 2, after cleaning by the prior art cleaning technique, the granularity of the wafer surface is 141; as shown in fig. 3, after the cleaning in example 1, the granularity of the wafer surface was 28, and the cleaning effect was significantly improved compared with the conventional cleaning technique.
Example 2
Step S1: and taking out the 25 silicon carbide substrate wafers from the product box, and putting the silicon carbide substrate wafers into corresponding PFA plugs.
Step S2: soaking the silicon carbide substrate wafer in SPM liquid medicine, wherein the liquid medicine proportion is as follows: 98% concentrated sulfuric acid (strong acid): 30% -32% hydrogen peroxide (oxide) =7:3; the temperature of the silicon carbide substrate wafer for soaking with SPM liquid medicine is 130 ℃, and the soaking treatment time is 30min.
Step S3: transferring the silicon carbide substrate wafer into a pure water ultrasonic tank, and performing pure water circulation overflow ultrasonic cleaning; the cycle period of the pure water circulation overflow ultrasonic cleaning is 4 times, and the cleaning treatment time is 15min.
Step S4: transferring the silicon carbide substrate wafer into an ammonia water tank, and soaking with ammonia water liquid medicine in the following ratio: 28% -30% ammonia water solution: deionized water pure water = 3.6:9; the temperature of the silicon carbide substrate wafer for soaking with the ammonia liquor is 75 ℃, and the soaking treatment time is 30min.
Step S5: transferring the silicon carbide substrate wafer into a pure water ultrasonic tank, and performing pure water circulation overflow ultrasonic cleaning; removing ammonia liquor on the surface of the silicon carbide substrate wafer; the cycle period of the pure water circulation overflow ultrasonic cleaning is 4 times, and the cleaning treatment time is 15min.
Furthermore, the ultrasonic cleaning frequency in the step S3 and the step S5 adopts a 40-80KHz frequency conversion mode, the ultrasonic power range is 800W, and the ultrasonic transmission mode is longitudinal liquid transmission.
Step S6: rapidly spin-drying a silicon carbide substrate wafer, wherein the spin-drying process is performed by using high-purity nitrogen to purge, and the spin-drying rotating speed of the silicon carbide substrate wafer is 1500rpm; the spin-drying time was 8 minutes.
Step S7: carrying out automatic double-sided cleaning on the spin-dried silicon carbide substrate wafer; the method specifically comprises the following steps:
step S71: fixing a silicon carbide substrate wafer by using a central rotary sucker, and rotating at a high speed, wherein the rotating speed of the silicon carbide substrate wafer is 1200rpm, and jet-type mist cleaning is performed by adopting two fluids of water and high-purity nitrogen (the pressure is 50 psi);
step S72: washing the two sides of the silicon carbide substrate wafer by deionized water and 4% HF liquid medicine respectively; the cycle period of the flushing is 4 times;
step S73: the rotational speed is increased to 2000rpm, and the moisture on the surface of the silicon carbide substrate wafer is dried by the high rotational speed.
As shown in fig. 4, the surface granularity of the silicon carbide substrate wafer before cleaning in the example 2 is 590; as shown in fig. 5, the particle size of the wafer surface after cleaning using the prior art cleaning technique is 148; as shown in fig. 6, after the cleaning in example 2, the granularity of the wafer surface was 24, and the cleaning effect was significantly improved compared with the conventional cleaning technique.
The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above examples, and any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principle of the present invention should be made in the equivalent manner, and the embodiments are included in the protection scope of the present invention.
Claims (9)
1. A cleaning method for efficiently removing silicon carbide substrate wafer pollution is characterized by comprising the following steps: the method comprises the following steps:
step S1: taking the silicon carbide substrate wafer out of the product box and putting the silicon carbide substrate wafer into a corresponding PFA clamping plug;
step S2: soaking the silicon carbide substrate wafer in SPM liquid medicine, wherein the liquid medicine proportion is as follows: 98% concentrated sulfuric acid (strong acid): 30% -32% hydrogen peroxide (oxide) =3:1 to 7:3;
step S3: transferring the silicon carbide substrate wafer into a pure water ultrasonic tank, and performing pure water circulation overflow ultrasonic cleaning; removing SPM liquid medicine and large-size particles on the surface;
step S4: transferring the silicon carbide substrate wafer into an ammonia water tank, and soaking with ammonia water liquid medicine in the following ratio: 28% -30% ammonia water solution: deionized water pure water = 2.4:8 to 3.6:9;
step S5: transferring the silicon carbide substrate wafer into a pure water ultrasonic tank, and performing pure water circulation overflow ultrasonic cleaning; removing ammonia liquor on the surface;
step S6: and (3) rapidly spin-drying the silicon carbide substrate wafer, wherein the spin-drying process uses high-purity nitrogen for purging.
2. The cleaning method for efficiently removing contamination from silicon carbide substrate wafers of claim 1, wherein: further comprising step S7: carrying out automatic double-sided cleaning on the spin-dried silicon carbide substrate wafer; the method specifically comprises the following steps:
step S71: fixing a silicon carbide substrate wafer by using a central rotating chuck, and rotating at a high speed; jet-type vaporific cleaning is carried out by adopting two fluids of water and high-purity nitrogen;
step S72: washing the two sides of the silicon carbide substrate wafer with deionized water and 2-4% HF liquid medicine respectively;
step S73: and finally, spin-drying the water on the surface of the silicon carbide substrate wafer through a high rotating speed.
3. The cleaning method for efficiently removing contamination from silicon carbide substrate wafers of claim 1, wherein: in the step S1, at most 25 pieces are used as a group and put into the corresponding PFA jam.
4. The cleaning method for efficiently removing contamination from silicon carbide substrate wafers of claim 1, wherein: in the step S2, the temperature control range of the silicon carbide substrate wafer for SPM chemical liquid soaking is between 110 and 130 ℃, and the soaking treatment time is between 15 and 30 minutes.
5. The cleaning method for efficiently removing contamination from silicon carbide substrate wafers of claim 1, wherein: in the step S3 and the step S5, the cycle period of the pure water circulating overflow ultrasonic cleaning is between 2 and 4 times, and the cleaning treatment time is controlled between 5 and 15 minutes.
6. The cleaning method for efficiently removing contamination from silicon carbide substrate wafers of claim 1, wherein: in the step S4, the temperature of the silicon carbide substrate wafer for soaking with ammonia liquor is controlled to be between 55 and 75 ℃, and the soaking treatment time is controlled to be between 15 and 30 minutes; the ammonia liquor is subjected to liquor supplementing of 100ml-200ml/h according to the volatilization degree.
7. The cleaning method for efficiently removing contamination from silicon carbide substrate wafers of claim 1, wherein: in the step S6, the spin-drying rotating speed of the silicon carbide substrate wafer is 800-1500 rpm; the spin-drying time is between 5 and 8 minutes.
8. The cleaning method for efficiently removing contamination from silicon carbide substrate wafers of claim 1, wherein: the ultrasonic cleaning frequency in the step S3 and the step S5 adopts a 40-80KHz frequency conversion mode, the ultrasonic power range is 500-800W, and the ultrasonic transmission mode is longitudinal liquid transmission.
9. The cleaning method for efficiently removing contamination from silicon carbide substrate wafers of claim 2, wherein: in the step S71, the silicon carbide substrate wafer rotates at a high speed of 800-1200rpm, and the pressure of the water and the high-purity nitrogen gas is 30-50 psi;
the cleaning time is between 60 and 80; in the step S72, the cycle period of the flushing is between 2 and 4 times; in the step S73, the rotating speed is increased to 1500-2000rpm, and the moisture on the surface of the silicon carbide substrate wafer is dried through the high rotating speed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310012004.0A CN116387137A (en) | 2023-01-05 | 2023-01-05 | Cleaning method for efficiently removing silicon carbide substrate wafer pollution |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310012004.0A CN116387137A (en) | 2023-01-05 | 2023-01-05 | Cleaning method for efficiently removing silicon carbide substrate wafer pollution |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116387137A true CN116387137A (en) | 2023-07-04 |
Family
ID=86977564
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310012004.0A Pending CN116387137A (en) | 2023-01-05 | 2023-01-05 | Cleaning method for efficiently removing silicon carbide substrate wafer pollution |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116387137A (en) |
-
2023
- 2023-01-05 CN CN202310012004.0A patent/CN116387137A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6088431B2 (en) | Compound semiconductor wafer cleaning method | |
| CN101276856A (en) | Process and equipment for etching and drying silicon solar cell | |
| WO2011158557A1 (en) | Method for cleaning silicon carbide semiconductor and apparatus for cleaning silicon carbide semiconductor | |
| KR100207469B1 (en) | Cleaning solution for semiconductor substrate and cleaning method thereby | |
| US5803980A (en) | De-ionized water/ozone rinse post-hydrofluoric processing for the prevention of silicic acid residue | |
| KR20050032943A (en) | Cleaning method and apparatus for manufacturing semiconductor device | |
| CN101826451A (en) | Process for cleaning ultra-thin oxide layer before growth | |
| CN116387137A (en) | Cleaning method for efficiently removing silicon carbide substrate wafer pollution | |
| CN104392898A (en) | Method for cleaning passivated GaAs wafer surface | |
| US6218085B1 (en) | Process for photoresist rework to avoid sodium incorporation | |
| CN101393852A (en) | Method for cleaning semiconductor wafer | |
| KR100841994B1 (en) | Method for manufacturing oxide film of silicon wafer | |
| JP2012004271A (en) | Method for cleaning silicon carbide semiconductor and device for cleaning silicon carbide semiconductor | |
| CN115116827A (en) | Cleaning method of high-purity monocrystal GaN | |
| CN113690131A (en) | Wet cleaning process | |
| Meuris et al. | Cleaning technology for improved gate oxide integrity | |
| CN113231386A (en) | Method for removing gallium nitride surface pollutants and gallium nitride substrate | |
| JPH0817775A (en) | Method for washing semiconductor device | |
| CN106611700A (en) | Preparation method of oxidization film in surface of silicon carbide | |
| JP2005327936A (en) | Cleaning method and manufacturing method of substrate | |
| CN104505338B (en) | Pre-cleaning method before a kind of silicon carbide wafer extension | |
| KR100732775B1 (en) | Cleaning bath for regenerating a dummy wafer and method of cleaning the dummy wafer using the same | |
| CN115995379A (en) | Cleaning method for metal residue on surface of silicon carbide wafer | |
| CN110211864B (en) | Cleaning method of silicon substrate | |
| KR960002075B1 (en) | Defect removing method of inter-insulating film surface lattis |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |