CN113322452B - Processing method of chemical plating metal and structure with chemical plating metal - Google Patents
Processing method of chemical plating metal and structure with chemical plating metal Download PDFInfo
- Publication number
- CN113322452B CN113322452B CN202110883722.6A CN202110883722A CN113322452B CN 113322452 B CN113322452 B CN 113322452B CN 202110883722 A CN202110883722 A CN 202110883722A CN 113322452 B CN113322452 B CN 113322452B
- Authority
- CN
- China
- Prior art keywords
- metal
- plating
- metal layer
- substrate structure
- transition metal
- 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.)
- Active
Links
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 271
- 239000002184 metal Substances 0.000 title claims abstract description 271
- 238000007747 plating Methods 0.000 title claims abstract description 111
- 239000000126 substance Substances 0.000 title abstract description 26
- 238000003672 processing method Methods 0.000 title abstract description 11
- 229910052723 transition metal Inorganic materials 0.000 claims abstract description 106
- 150000003624 transition metals Chemical class 0.000 claims abstract description 106
- 239000000758 substrate Substances 0.000 claims abstract description 70
- 238000000034 method Methods 0.000 claims description 54
- 230000008569 process Effects 0.000 claims description 41
- 239000002253 acid Substances 0.000 claims description 18
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 16
- 239000000463 material Substances 0.000 claims description 11
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 8
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 7
- 230000000694 effects Effects 0.000 claims description 7
- 229910052759 nickel Inorganic materials 0.000 claims description 7
- 239000011701 zinc Substances 0.000 claims description 5
- 229910052782 aluminium Inorganic materials 0.000 claims description 4
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 3
- 229910052709 silver Inorganic materials 0.000 claims description 3
- 239000004332 silver Substances 0.000 claims description 3
- -1 silver ions Chemical class 0.000 claims description 3
- 229910052725 zinc Inorganic materials 0.000 claims description 3
- 230000015572 biosynthetic process Effects 0.000 claims description 2
- 239000007769 metal material Substances 0.000 claims 1
- 230000002159 abnormal effect Effects 0.000 abstract description 5
- 239000000243 solution Substances 0.000 description 59
- 238000007772 electroless plating Methods 0.000 description 24
- 238000005554 pickling Methods 0.000 description 11
- 238000010586 diagram Methods 0.000 description 9
- 238000005516 engineering process Methods 0.000 description 6
- 239000004065 semiconductor Substances 0.000 description 6
- 238000004140 cleaning Methods 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000006073 displacement reaction Methods 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 230000001681 protective effect Effects 0.000 description 4
- 238000005406 washing Methods 0.000 description 4
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 3
- 230000009257 reactivity Effects 0.000 description 3
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- 230000005856 abnormality Effects 0.000 description 2
- 239000003929 acidic solution Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000000356 contaminant Substances 0.000 description 2
- 238000009713 electroplating Methods 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 238000004381 surface treatment Methods 0.000 description 2
- JBQYATWDVHIOAR-UHFFFAOYSA-N tellanylidenegermanium Chemical compound [Te]=[Ge] JBQYATWDVHIOAR-UHFFFAOYSA-N 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000005137 deposition process Methods 0.000 description 1
- 238000002845 discoloration Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000004377 microelectronic Methods 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
- C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
- C23C18/18—Pretreatment of the material to be coated
- C23C18/1803—Pretreatment of the material to be coated of metallic material surfaces or of a non-specific material surfaces
- C23C18/1824—Pretreatment of the material to be coated of metallic material surfaces or of a non-specific material surfaces by chemical pretreatment
- C23C18/1837—Multistep pretreatment
- C23C18/1841—Multistep pretreatment with use of metal first
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
- C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
- C23C18/31—Coating with metals
-
- 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
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/28—Manufacture of electrodes on semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/268
- H01L21/283—Deposition of conductive or insulating materials for electrodes conducting electric current
- H01L21/288—Deposition of conductive or insulating materials for electrodes conducting electric current from a liquid, e.g. electrolytic deposition
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Chemically Coating (AREA)
Abstract
The invention provides a processing method of chemical plating metal and a structure with the chemical plating metal. In the processing method, the target metal can be smoothly formed on the top metal layer through the first pre-plating treatment and the second pre-plating treatment, the substrate structure is placed in the plating solution containing the target metal after the first transition metal is deplated, at the moment, if the first transition metal is remained on the top metal layer, the remained first transition metal can replace the target metal on the top metal layer, the influence of the remained first transition metal on the subsequent second pre-plating treatment is avoided, the integral texture of the subsequently formed second transition metal is guaranteed to be compact and fine, the quality of the subsequently replaced target metal is further improved, and the problems that the color of the chemical plating metal formed by the final chemical plating is abnormal, the surface bulges and the like are prevented.
Description
Technical Field
The invention relates to the technical field of semiconductors, in particular to a processing method of chemical plating metal and a structure with the chemical plating metal.
Background
Electroless plating is a novel metal surface treatment technology, and particularly relates to a deposition process for generating metal through controllable oxidation-reduction reaction under the catalytic action of the metal. Compared with electroplating, the chemical plating technology has the characteristics of uniform plating layer, flexible process, no need of direct-current power supply equipment and the like, and the chemical plating technology replaces the electroplating technology in many fields to become an environment-friendly surface treatment technology.
Electroless plating techniques have also found widespread use in the field of semiconductor and microelectronic integrated manufacturing. Including the formation of electroless metal plating through an electroless plating process that can form metal contact pads for electrically extracting semiconductor devices and the like from a substrate structure.
With the increasingly wide application of the chemical plating technology, the chemical plating process needs to be further optimized to improve the quality of the chemical plating metal. For example, the electroless plating metal prepared by the prior electroless plating process often has the problems of abnormal color, bulge and the like.
Disclosure of Invention
The invention aims to provide a processing method of chemical plating metal, which aims to solve the problems that the prepared chemical plating metal is often abnormal in color, bulges and the like in the existing chemical plating process.
In order to solve the technical problem, the invention provides a processing method of electroless plating metal, which comprises the following steps: providing a substrate structure, wherein a top metal layer is formed on one surface of the substrate structure; performing a first pre-plating process to form a first transition metal on a surface of the top metal layer; placing the substrate structure in a deplating solution for removing the first transition metal; placing the substrate structure in a first plating solution containing a target metal; performing a second pre-plating process to form a second transition metal on the surface of the top metal layer; and placing the substrate structure in a second plating solution containing a target metal to replace the target metal on the top metal layer so as to chemically plate the target metal.
Optionally, when the first transition metal is removed, a part of the first transition metal remains on the top metal layer; and placing the substrate structure in a first plating solution containing a target metal, wherein the target metal is replaced on the top metal layer by the residual first transition metal.
Optionally, the first transition metal is left in a grain boundary of an adjacent metal lattice of the top metal layer, and a target metal formed by replacement is formed in the grain boundary; and, while performing the second pre-plating treatment, the second transition metal covers the target metal within the grain boundaries.
Optionally, before performing the first pre-plating treatment, the method further includes: the substrate structure is placed in an acid solution to roughen a top surface of the top metal layer.
Optionally, the method of placing the substrate structure in a deplating solution to remove the first transition metal includes: and placing the substrate structure in the acid solution to perform deplating treatment.
Optionally, a silver metal layer is formed on the other surface of the substrate structure opposite to the top metal layer; and, upon placing the substrate structure in the acid solution, the silver metal layer is eroded to dissolve silver ions in the acid solution.
Optionally, the material of the first transition metal and the material of the second transition metal are the same. Wherein the materials of the first transition metal and the second transition metal may each include zinc.
Optionally, the material of the target metal comprises nickel. And the material of the top metal layer comprises aluminum.
Optionally, an IGBT device is formed in the substrate structure, and a collector metal is formed on the other surface of the substrate structure opposite to the top metal layer.
The invention also provides a structure with electroless metal plating, which is formed by the method for processing the electroless metal plating, and the structure comprises the following components: the device comprises a substrate structure, a first metal layer and a second metal layer, wherein a top metal layer is formed on one surface of the substrate structure; and electroless metal plating formed on the top metal layer.
In the processing method of electroless plating provided by the invention, a first transition metal is formed on the surface of the top metal layer through a first pre-plating treatment, and the first transition metal is deplated to remove the poor-quality part on the surface of the top metal layer (for example, the metal on the surface of the top metal layer is rough and loose, and the grain size is large). And after the first transition metal is deplated, the substrate structure is also placed in a plating solution containing a target metal, and at the moment, even if the first transition metal is remained on the top metal layer, the remained first transition metal can replace the target metal on the top metal layer, so that the influence of the remained first transition metal on the subsequently executed second pre-plating treatment is avoided, and the integral texture of the subsequently formed second transition metal is guaranteed to be compact and fine. Then, when the substrate structure is placed in a plating solution containing the target metal, the target metal can be replaced by the second transition metal with compact integral texture on the top metal layer, so that the chemical plating metal (namely, the target metal) formed on the top metal layer has higher quality, and the problems that the chemical plating metal formed in the traditional process is easy to have abnormal color, bulge on the surface and the like are solved.
Drawings
FIG. 1 is a schematic flow diagram of a process for electroless plating.
FIG. 2 is a schematic diagram of a process for electroless plating.
FIG. 3 is a schematic flow chart of a method of electroless plating metal in one embodiment of the invention.
FIG. 4 is a schematic structural diagram of electroless metal plating process in one embodiment of the present invention.
FIG. 5 is a diagram illustrating a substrate structure according to an embodiment of the invention.
Wherein the reference numbers are as follows: 100-a substrate structure; 110-top metal layer; 120-protective film; 210-a first transition metal; 220-a second transition metal; 310 — a first target metal; 300-second target metal.
Detailed Description
As discussed in the background, the prior art electroless plating processes still have deficiencies and need further optimization.
FIG. 1 is a schematic flow diagram of a process for electroless metal plating, and FIG. 2 is a schematic structural diagram of an electroless metal plating process. As shown in fig. 1 and 2, an electroless plating process, for example, comprises: step one, performing acidity on a substrate structure with a top metal layer 110 to remove an oxide layer on the surface of the top metal layer 110; step two, performing a first pre-plating process to form a first transition metal 210 on the surface of the top metal layer 110; step three, placing the substrate structure in a deplating solution to remove the first transition metal; step four, performing a second pre-plating process to form a second transition metal 220 on the surface of the top metal layer 110; and step five, placing the substrate structure into a plating solution containing target metal to replace the second transition metal with the target metal 300' for chemically plating the target metal.
In the above processing process, the rough and loose metal on the surface of the top metal layer 110 is replaced by the first transition metal 210 through the first pre-plating treatment, the first transition metal 210 correspondingly forms the loose transition metal according to the rough and loose metal on the surface of the top metal layer, and the rough and loose transition metal is further removed in the deplating solution, so that the second transition metal 220 with finer texture can be formed when the second pre-plating treatment is performed, and the quality of the target metal 300' formed by the subsequent replacement is correspondingly improved. However, the above-mentioned processing still has the problems of the produced electroless metal plating (i.e., the target metal 300') such as surface discoloration and morphology abnormality.
In view of the above-mentioned processing procedures, the inventors of the present invention have found, after research, that the produced electroless metal plating is susceptible to abnormalities, one reason for which is: when the second transition metal 220 is formed by performing the second pre-plating process, the region corresponding to the remaining first transition metal continues the texture of the remaining first transition metal and further grows into a rough and loose second transition metal, which affects the overall compactness of the second transition metal 220, thereby causing the problem of the surface of the electroless plating metal (i.e., the target metal 300') being discolored and raised.
As a result of further research on the above-mentioned reasons, the inventors of the present invention have found that one reason why the first transition metal 210 remains during the deplating process is that: the deplating liquid adopted during deplating and the pickling liquid adopted during pickling are shared, and the pickling liquid has certain pollution after being subjected to previous pickling, so that the deplating effect is influenced and residues are caused when the pickling liquid is used for deplating. For this reason, the problem of residue as described above can be overcome by adding a deplating solution, which, however, also increases the processing cost of electroless plating and reduces the availability of the respective chemical solutions.
In view of the above, the present invention provides a method for optimizing electroless plating, which specifically comprises: the substrate structure is placed in a plating solution containing a target metal after deplating the first transition metal. At this time, if the first transition metal remains on the top metal layer, the remaining first transition metal is replaced to form the target metal, so that the second transition metal formed in the second pre-plating process continues to expose the fine and dense metal growth, thereby improving the compactness of the second transition metal and further improving the quality of the finally formed electroless plating metal.
The method for optimizing electroless plating metal proposed by the present invention is described in further detail below with reference to fig. 3 and 4. Fig. 3 is a schematic flow chart of a processing method of electroless plating metal in an embodiment of the invention, and fig. 4 is a schematic structural diagram of a processing process of electroless plating metal in an embodiment of the invention. The advantages and features of the present invention will become more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention. It will be understood that relative terms, such as "above," "below," "top," "bottom," "above," and "below," may be used in relation to various elements shown in the figures. These relative terms are intended to encompass different orientations of the elements in addition to the orientation depicted in the figures. For example, if the device were inverted relative to the view in the drawings, an element described as "above" another element, for example, would now be below that element.
First, a substrate structure is provided, and a top metal layer 110 is formed on one surface of the substrate structure. Wherein the top metal layer 110 is usually in the form of a metal lattice. Further, the material of the top metal layer 110 includes, for example, copper, aluminum, and the like.
It should be noted that only the top metal layer 110 in the substrate structure is illustrated in fig. 4, and other components (e.g., semiconductor devices, etc.) in the substrate structure are not illustrated. The top metal layer 110 is, for example, a top metal layer of an interconnect structure for electrically connecting a semiconductor device (not shown) therebelow.
In a specific application, the semiconductor device formed in the substrate structure may be a power device, and the power device may further be an IGBT device. For example, referring to fig. 5, for the case where an IGBT device (not shown) is formed in the substrate structure 100, the top metal layer 110 may be formed on the front surface 100a of the substrate structure 100, and a collector metal (not shown) connected to the collector of the IGBT device may be formed on the back surface 100b of the substrate structure 100. The collector metal may include a plurality of metal layers stacked in sequence, for example, a titanium metal layer, a nickel metal layer, a silver metal layer, etc., which are stacked in sequence, wherein the silver metal layer may be disposed on an outermost layer to protect other metal layers inside thereof from oxidation by using the silver metal layer having relatively stable properties.
Based on this, before performing the electroless plating process on the front surface 100a of the substrate structure 100, a protection film 120 may be attached on the back surface 100b of the substrate structure 100 to protect the back surface. However, as shown in fig. 5, the protective film 120 is not generally attached to the edge portion of the back surface of the substrate completely, and one reason is that: the edge of the substrate structure 100 (e.g., a wafer) is usually curved, and when the protection film 120 is attached to the curved edge, a gap is easily formed, which may become an injection channel for a subsequent etchant, and may cause the backside of the substrate to be eroded. For this reason, the protective film 120 is usually not attached to the edge portion of the substrate, and thus the edge portion of the back surface of the substrate is exposed from the protective film 120.
In this embodiment, before pre-plating the first transition metal, the method further includes: the top metal layer 110 of the substrate structure 100 is micro-etched (micho-Etch) to roughen the surface of the top metal layer 110. For example, from the first to the second structure diagrams shown in fig. 4, the overall roughness of the top surface of the top metal layer 110 is increased, which is beneficial to improve the bonding strength between the subsequently formed electroless metal and the top metal layer 110. It should be appreciated that the "increased overall roughness of the top surface of the top metal layer 110" described herein refers to the overall surface roughness of the top metal layer, and not to the roughness of the metal lattice of the top metal layer.
It should be noted that the metal on the outer surface of the top metal layer 110 is generally susceptible to the external environment, so that the texture of the metal on the outer surface is rough and loose, which can be shown in that the metal lattice on the outer surface is relatively rough, the grain size is large, and contaminants are easily remained in the grain boundaries of adjacent lattices. Therefore, in this embodiment, the first transition metal is pre-plated and removed to correspondingly remove the portion of the top metal layer 110 with poor texture on the outer surface thereof.
In this embodiment, before the first pre-plating process is performed, the method further includes: and placing the substrate structure in a pickling solution for pickling to remove an oxide layer on the surface of the top metal layer 110, so as to be beneficial to forming a coating on the top metal layer 110 subsequently. Wherein the acid wash may comprise a nitric acid solution. And, the oxide layer on the surface of the top metal layer 110 is, for example, a natural oxide layer, and the top surface of the top metal layer 110, which is exposed to the outside, is easily oxidized to form aluminum oxide.
In addition, as described above, the edge portion of the back surface of the substrate structure 100 is not covered by the protective film 120 and is exposed, that is, the metal layer on the other surface of the substrate structure 100 opposite to the top metal layer is exposed, so that the exposed portion is correspondingly contacted with the acid washing solution during the acid washing process, and the exposed collector metal is easily dissolved in the acid washing solution to contaminate the acid washing solution. For example, the outermost silver metal layer of the collector metal is corroded by the pickling solution, and silver ions are dissolved in the pickling solution.
Referring next to fig. 3 and 4, a first pre-plating process is performed to form a first transition metal 210 on the surface of the top metal layer 110.
Specifically, the substrate structure is placed in a pre-plating solution to perform the first pre-plating treatment. Wherein the metal reactivity of the first transition metal 210 is lower than that of the top metal layer 110, so that the metal of the top metal layer 110 can replace the first transition metal 210 based on a replacement reaction. In the present embodiment, the first transition metal 210 includes, for example, zinc (Zn). As mentioned above, the metal on the outer surface of the top metal layer 110 is rough and loose, and the first transition metal 210 formed by replacement is also rough and loose in texture and larger in grain size.
It should be noted that, when the top metal layer 110 is an aluminum metal layer, the top surface thereof is easily oxidized to form aluminum oxide, and the aluminum oxide is easily etched and removed in the pre-plating solution, so as to expose the aluminum material for the displacement reaction. In this embodiment, the pre-plating solution may be an alkaline solution.
With continued reference to fig. 3 and 4, the substrate structure is placed in a deplating solution for removing the first transition metal 210. At this time, it is equivalent to remove the portion of the top metal layer 110 with poor texture on the outer surface thereof and expose the portion of the top metal layer 110 with finer and denser texture on the inner surface thereof.
Wherein the deplating solution may be an acidic solution, and the acidic solution may further be a nitric acid solution. In this embodiment, the deplating process of the first transition metal 210 can be performed by directly using the pickling solution, i.e., the deplating solution and the pickling solution can be shared, so as to improve the utilization rate of the chemical solution and reduce the cost. As described above, when the substrate structure is subjected to the acid cleaning using the acid cleaning solution, there is a possibility that contaminants remain in the acid cleaning solution (for example, when the substrate structure is subjected to the acid cleaning, the collector metal on the back surface of the substrate structure is corroded to contaminate the acid cleaning solution), and in this case, the deplating effect on the first transition metal 210 is easily affected, and a part of the first transition metal 210 remains on the top metal layer 110. Generally, the first transition metal 210 generally tends to remain in the grain boundaries of the adjacent metal lattices of the top metal layer 110.
Further, after the first transition metal layer 210 is deplated, an oxide layer may be formed on the top surface of the exposed top metal layer 110. For example, aluminum metal, which is very reactive in nature, is oxidized to form an oxide layer within a short time of exposure to air.
With continued reference to fig. 3 and 4, the substrate structure is placed in a first plating solution containing a target metal. The target metal includes, for example, nickel (Ni).
Wherein the metal reactivity of the target metal is lower than the metal reactivity of the first transition metal 210. Therefore, when the first transition metal 210 remains on the top metal layer 110, the remaining first transition metal 210 can replace the target metal on the top metal layer 110. It should be noted that the residual first transition metal 210 generally remains in the grain boundaries of the adjacent metal lattices of the top metal layer 110, and is coarse and loose in texture and has a large grain size, so that the target metal to be formed by substitution is also located in the grain boundaries of the adjacent metal lattices of the top metal layer 110 with a high probability and has a large grain size. In this embodiment, the target metal formed by the replacement of the remaining first transition metal 210 is defined as a first target metal 310.
It is also noted that it is often difficult to directly electroless plate the target metal on the top metal layer 110 (e.g., it is difficult to directly electroless nickel on an aluminum metal surface), and therefore a transition metal (e.g., zinc) is used as an intermediate medium to achieve that the target metal can be electroless plated on the top metal layer. As such, when the substrate structure is placed in the target metal-containing plating solution, the target metal is not formed on the metal surface of the top metal layer 110, and only the remaining first transition metal 210 can perform a displacement reaction with the target metal in the plating solution to displace the target metal from the top metal layer 110. The reasons for this may be: the exposed metal surface of the top metal layer 110 is easily oxidized to form an oxide layer, and specifically, the top metal layer 110 is exposed to metal (Al) immediately after the deplating process is completed, and the exposed metal surface is oxidized to form a dense and stable oxide layer (Al) by contacting with air in a short time2O3) The oxide layer (Al)2O3) The metal (Al) of the top metal layer is isolated from the plating solution, so that the replacement reaction is difficult to proceed and the electroless nickel plating cannot be performed, however, the residual first transition metal (Zn) is not oxidized and still exposed, and the target metal (Ni) can be replaced by the residual first transition metal (Zn). For example, as shown in the structure diagram of fig. 4 after the substrate structure is placed in the first plating solution, the surface of the region where the target metal is not replaced is covered with an oxide layer.
With continued reference to fig. 3 and 4, a second pre-plating process is performed to form a second transition metal 220 on the surface of the top metal layer. The thickness of the second transition metal 220 may be adjusted according to the thickness of a target metal to be formed subsequently, and specifically, the thickness of the second transition metal 220 is greater than or equal to the thickness of the target metal to be formed subsequently, so as to meet the replacement requirement of the target metal.
Specifically, the substrate structure is placed in a pre-plating solution to perform the second pre-plating treatment. The metal activity of the second transition metal 220 is lower than that of the top metal layer 110, so that the metal of the top metal layer 110 can replace the second transition metal 220 based on a replacement reaction. Unlike the first pre-plating process, the second pre-plating process is grown based on the fine and dense texture of the top metal layer 110, and thus the texture of the second transition metal 220 is correspondingly fine, dense, and small in grain size.
In addition, the metal activity of the second transition metal 220 is higher than that of the first target metal 310, so that the first target metal 310 formed in the grain boundary does not undergo a displacement reaction with the ions containing the second transition metal in the pre-plating solution. And the second transition metal 220 formed by the displacement grows from the surface of the metal lattice and covers the grain boundaries, correspondingly covering the first target metal 310 located within the grain boundaries.
In this embodiment, the second transition metal 220 and the first transition metal 210 are made of the same material, and each includes, for example, zinc (Zn). And the pre-plating solution of the second pre-plating treatment can be shared with the pre-plating solution of the first pre-plating treatment, so that the processing cost is saved, and the utilization rate of the chemical solution is improved.
Referring next to fig. 3 and 4, the substrate structure is placed in a second plating solution containing a target metal to replace the target metal on the top metal layer 110 with the second transition metal 220 to electrolessly plate the target metal. In the present embodiment, the target metal formed by the replacement of the second transition metal 220 is defined as a second target metal 300.
The metal activity of the target metal is lower than that of the second transition metal 220, so that the second transition metal 220 on the top metal layer 110 can replace the target metal in the second plating solution based on a replacement reaction.
As described above, the texture of the second transition metal 220 is fine, dense, and small in grain size, and thus the second target metal 300 formed by replacement has a correspondingly fine, dense, and small grain size. Compared with the electroless plating metal formed by the method shown in the figures 1 and 2, the electroless plating metal (i.e. the second target metal 300) formed by the processing method based on the embodiment has uniform overall color and smooth appearance, and the quality of the electroless plating metal is effectively improved.
Further, the second plating solution containing the target metal is, for example, a plating solution containing nickel. In the above steps of this embodiment, the plating solution containing the target metal may be used in common, that is, the first plating solution containing the target metal and the second plating solution containing the target metal may be the same plating solution, so as to save the processing cost and improve the utilization rate of the chemical solution.
In summary, in the processing method of electroless plating provided in this embodiment, the target metal can be smoothly formed on the top metal layer through the first pre-plating treatment and the second pre-plating treatment. And after the first transition metal is removed, the substrate structure is placed in a plating solution containing a target metal, so that even if the first transition metal remains on the top metal layer, the target metal is replaced on the top metal layer by the first transition metal, the influence of the remaining first transition metal on the second pre-plating treatment which is subsequently executed is avoided, the overall texture of the subsequently formed second transition metal is guaranteed to be compact and fine, and thus, the target metal which is subsequently replaced by the second transition metal has relatively high quality, and the problems of abnormal color, surface bulging and the like of the chemical plating metal (namely, the second target metal) which is finally formed by chemical plating are prevented.
It should be noted that, although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to the embodiments. It will be apparent to those skilled in the art from this disclosure that many changes and modifications can be made, or equivalents modified, in the embodiments of the invention without departing from the scope of the invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the protection scope of the technical solution of the present invention, unless the content of the technical solution of the present invention is departed from.
It should be further understood that the terms "first," "second," "third," and the like in the description are used for distinguishing between various components, elements, steps, and the like, and are not intended to imply a logical or sequential relationship between various components, elements, steps, or the like, unless otherwise indicated or indicated.
It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. It must be noted that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to "a step" or "an apparatus" means a reference to one or more steps or apparatuses and may include sub-steps as well as sub-apparatuses. All conjunctions used should be understood in the broadest sense. And, the word "or" should be understood to have the definition of a logical "or" rather than the definition of a logical "exclusive or" unless the context clearly dictates otherwise.
Claims (11)
1. A method for processing electroless metal plating, comprising:
providing a substrate structure, wherein a top metal layer is formed on one surface of the substrate structure;
performing a first pre-plating process to form a first transition metal on a surface of the top metal layer;
placing the substrate structure in a deplating solution for removing the first transition metal;
placing the substrate structure in a first plating solution containing a target metal, wherein the metal activity of the target metal is lower than the metal activity of the first transition metal;
performing a second pre-plating treatment to form a second transition metal on the surface of the top metal layer, wherein the material of the first transition metal is the same as that of the second transition metal; and the number of the first and second groups,
and placing the substrate structure in a second plating solution containing target metal to replace the target metal on the top metal layer so as to chemically plate the target metal.
2. The electroless metal plating process of claim 1 wherein a portion of said first transition metal remains on said top metal layer during removal of said first transition metal;
and placing the substrate structure in a first plating solution containing a target metal, wherein the target metal is replaced on the top metal layer by the residual first transition metal.
3. The electroless metal plating process of claim 2 wherein said first transition metal remains in grain boundaries of adjacent metal lattices of said top metal layer, and the target metal for substitutional formation is formed in said grain boundaries;
and, while performing the second pre-plating treatment, the second transition metal covers the target metal within the grain boundaries.
4. The electroless metal plating process of claim 1 further comprising, prior to performing said first pre-plating treatment: the substrate structure is placed in an acid solution to roughen a top surface of the top metal layer.
5. The method of electroless metal plating process of claim 4 wherein the step of exposing the substrate structure to a stripping solution to remove the first transition metal comprises: and placing the substrate structure in the acid solution to perform deplating treatment.
6. The electroless metal plating process of claim 5 wherein a silver metal layer is formed on the other surface of the substrate structure opposite the top metal layer; and, upon placing the substrate structure in the acid solution, the silver metal layer is eroded to dissolve silver ions in the acid solution.
7. The electroless metal plating process of claim 1 wherein the material of each of said first transition metal and said second transition metal comprises zinc.
8. The electroless metal plating process of claim 1 wherein the target metal material comprises nickel.
9. The electroless metal plating process of claim 1 wherein the material of the top metal layer comprises aluminum.
10. The electroless metal plating process of claim 1 wherein an IGBT device is formed in the substrate structure and a collector metal is formed on the other surface of the substrate structure opposite the top metal layer.
11. A structure having electroless metal plating formed using the electroless metal plating process of any one of claims 1 to 10, comprising:
the device comprises a substrate structure, a first metal layer and a second metal layer, wherein a top metal layer is formed on one surface of the substrate structure; and electroless metal plating formed on the top metal layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110883722.6A CN113322452B (en) | 2021-08-03 | 2021-08-03 | Processing method of chemical plating metal and structure with chemical plating metal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110883722.6A CN113322452B (en) | 2021-08-03 | 2021-08-03 | Processing method of chemical plating metal and structure with chemical plating metal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113322452A CN113322452A (en) | 2021-08-31 |
| CN113322452B true CN113322452B (en) | 2021-11-19 |
Family
ID=77426830
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110883722.6A Active CN113322452B (en) | 2021-08-03 | 2021-08-03 | Processing method of chemical plating metal and structure with chemical plating metal |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113322452B (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101250733A (en) * | 2008-04-16 | 2008-08-27 | 丹阳利华电子有限公司 | Technique for producing aluminum magnesium plating copper wire copper-coating |
| CN102732865A (en) * | 2012-04-11 | 2012-10-17 | 中国电子科技集团公司第五十五研究所 | Chemical nickel plating solution and aluminum silicon carbide plating method |
| CN111334795B (en) * | 2020-03-12 | 2022-04-19 | 成都四威高科技产业园有限公司 | Surface plating process for diamond aluminum composite material |
| CN111599679B (en) * | 2020-05-29 | 2023-03-07 | 上海华虹宏力半导体制造有限公司 | Metallization method of semiconductor device |
-
2021
- 2021-08-03 CN CN202110883722.6A patent/CN113322452B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN113322452A (en) | 2021-08-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| PH12015500543B1 (en) | Method for metallization of solar cell substrates | |
| CN113122845B (en) | Preparation method of aluminum alloy metal plating part | |
| CN113322452B (en) | Processing method of chemical plating metal and structure with chemical plating metal | |
| EP1427869A2 (en) | Regeneration method for a plating solution | |
| KR100964030B1 (en) | Method for forming a through-hole electrode and structure therefore | |
| CN103233250A (en) | Method for electroplating goldfinger with thick gold layer | |
| CN105374701A (en) | Activation Treatments in Plating Processes | |
| CN111636077A (en) | Process for preventing ceramic chip from being plated with nickel or gold by creeping plating | |
| CN113678232B (en) | Semiconductor device and method for manufacturing the same | |
| CN110565093A (en) | molybdenum-copper composite material plating method | |
| JP4647159B2 (en) | Formation method of electroless plating film | |
| JP5135617B2 (en) | Electroless plating method | |
| CN1430271A (en) | Semiconductor device and its manufacturing method | |
| TWI638065B (en) | Semiconductor device | |
| CN118280888B (en) | Semiconductor integrated manufacturing system and method for wafer-level metal deposition | |
| JP4252549B2 (en) | Semiconductor device manufacturing method and semiconductor manufacturing apparatus | |
| JPH09326395A (en) | Forming method of electrode of semiconductor device | |
| CN109468641B (en) | Method for chemically-physically removing copper and copper-zinc alloy based silver coating | |
| CN220874792U (en) | Hole metallized aluminum alloy circuit board | |
| JPH0575238A (en) | Circuit board and its manufacture | |
| CN108239743A (en) | A kind of preparation method of quartz crystal | |
| CN118472119A (en) | Heterojunction battery treatment process and device | |
| US10851441B2 (en) | Plug-in connector and semi-finished product made from an aluminum alloy strip | |
| JP2002237497A (en) | Electrode forming method of semiconductor element | |
| Chou et al. | The influence of boric acid and dissolved oxygen on the morphology of electroless palladium films |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20220705 Address after: No. 518, Linjiang Road, Gaobu Town, Yuecheng District, Shaoxing City, Zhejiang Province Patentee after: Shaoxing SMIC integrated circuit manufacturing Co.,Ltd. Patentee after: SMIC international integrated circuit manufacturing (Shanghai) Co., Ltd Address before: 518 Shaoxing Road, Zhejiang Province Patentee before: Shaoxing SMIC integrated circuit manufacturing Co.,Ltd. |