CN114843177A - Manufacturing method of trench Schottky structure - Google Patents
Manufacturing method of trench Schottky structure Download PDFInfo
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- CN114843177A CN114843177A CN202210394894.1A CN202210394894A CN114843177A CN 114843177 A CN114843177 A CN 114843177A CN 202210394894 A CN202210394894 A CN 202210394894A CN 114843177 A CN114843177 A CN 114843177A
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- 238000004519 manufacturing process Methods 0.000 title claims abstract description 31
- 229910021420 polycrystalline silicon Inorganic materials 0.000 claims abstract description 72
- 238000000034 method Methods 0.000 claims abstract description 65
- 229910052751 metal Inorganic materials 0.000 claims abstract description 53
- 239000002184 metal Substances 0.000 claims abstract description 53
- 238000005530 etching Methods 0.000 claims abstract description 50
- 238000000151 deposition Methods 0.000 claims abstract description 31
- 230000004888 barrier function Effects 0.000 claims abstract description 29
- 238000001259 photo etching Methods 0.000 claims abstract description 20
- 230000001590 oxidative effect Effects 0.000 claims abstract description 13
- 238000003384 imaging method Methods 0.000 claims abstract description 5
- 229920005591 polysilicon Polymers 0.000 claims description 41
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 8
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- 150000002739 metals Chemical class 0.000 claims description 3
- 229910052759 nickel Inorganic materials 0.000 claims description 3
- 229910052709 silver Inorganic materials 0.000 claims description 3
- 229910052719 titanium Inorganic materials 0.000 claims description 3
- 230000000873 masking effect Effects 0.000 claims 1
- 230000008569 process Effects 0.000 abstract description 36
- 239000004065 semiconductor Substances 0.000 abstract description 3
- 238000001312 dry etching Methods 0.000 description 8
- 230000003647 oxidation Effects 0.000 description 8
- 238000007254 oxidation reaction Methods 0.000 description 8
- 230000009471 action Effects 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 230000008021 deposition Effects 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 229920002120 photoresistant polymer Polymers 0.000 description 4
- 238000005498 polishing Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000000227 grinding Methods 0.000 description 3
- 238000001039 wet etching Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000011049 filling Methods 0.000 description 2
- 238000001465 metallisation Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 150000004767 nitrides Chemical class 0.000 description 2
- 238000000206 photolithography Methods 0.000 description 2
- 238000001311 chemical methods and process Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
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- 230000005684 electric field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
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- 238000001459 lithography Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
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- H—ELECTRICITY
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- 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
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/40—Electrodes ; Multistep manufacturing processes therefor
- H01L29/43—Electrodes ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
- H01L29/47—Schottky barrier electrodes
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Abstract
The application provides a manufacturing method of a trench Schottky structure, and relates to the technical field of semiconductor processes. The method comprises the steps of firstly etching a groove on an epitaxial layer by using an imaging photoetching plate layer, growing a dielectric layer on the basis of the inner wall of the groove, then depositing polycrystalline silicon along the surface of the epitaxial layer, wherein the polycrystalline silicon is positioned on the surface of the epitaxial layer and in the groove, oxidizing the polycrystalline silicon positioned on the surface of the epitaxial layer to form an oxide layer, then etching a contact hole on the basis of the oxide layer and exposing the groove, and finally depositing barrier metal and front metal on the basis of the contact hole to form a groove Schottky structure. The manufacturing method of the trench Schottky structure has the advantages of being capable of saving manufacturing cost and manufacturing process.
Description
Technical Field
The application relates to the technical field of semiconductor processes, in particular to a method for manufacturing a trench Schottky structure.
Background
In the production process of semiconductor devices, especially in the manufacture of trench schottky devices, it is usually necessary to remove the polysilicon on the surface of the epitaxial layer and retain the polysilicon in the trench to realize the subsequent processes.
In the conventional manufacturing process, after filling the polysilicon, polysilicon on the surface of the epitaxial layer is removed in a polysilicon planarization mode.
However, since the current polysilicon planarization generally adopts a dry etching process, and needs a dry etching device, the process cost is relatively high, and the process flow is relatively complex.
In summary, the problems of high cost and complex process exist in the prior art when removing polysilicon.
Disclosure of Invention
The invention aims to provide a method for manufacturing a trench Schottky structure, which aims to solve the problems of high cost and complex process in the process of removing polycrystalline silicon in the prior art.
In order to achieve the above purpose, the embodiments of the present application employ the following technical solutions:
the embodiment of the application provides a method for manufacturing a trench Schottky structure, which comprises the following steps:
etching a groove on the epitaxial layer by using the imaging photoetching plate layer;
growing a dielectric layer on the basis of the inner wall of the groove;
depositing polycrystalline silicon along the surface of the epitaxial layer, wherein the polycrystalline silicon is positioned on the surface of the epitaxial layer and in the groove;
oxidizing the polycrystalline silicon on the surface of the epitaxial layer to form an oxide layer;
etching a contact hole based on the oxide layer and exposing a groove;
and depositing a barrier metal and a front metal based on the contact hole to form a trench Schottky structure.
Optionally, oxidizing the polysilicon on the surface of the epitaxial layer includes:
oxidizing all the polycrystalline silicon on the surface of the epitaxial layer, wherein the polycrystalline silicon in the groove is not oxidized; or
And oxidizing all the polysilicon on the surface of the epitaxial layer and the polysilicon with the preset depth in the groove.
Optionally when saidThe photoetching plate layer is SiO 2 During layer etching, the step of etching the contact hole based on the oxide layer comprises the following steps of:
and synchronously etching the oxide layer and the photoetching plate layer in the preset area to form a contact hole.
Optionally, when the photoetching plate layer is non-SiO 2 During layer etching, the step of etching the contact hole based on the oxide layer comprises the following steps of:
and etching the oxide layer in the preset area, and etching the photoetching plate layer to form the contact hole.
Optionally, the step of depositing a barrier metal and a front metal based on the contact hole to form a trench schottky structure comprises:
depositing a barrier metal based on the contact hole;
and etching the barrier metal to form a preset pattern.
Optionally, the step of depositing a barrier metal and a front metal based on the contact hole to form a trench schottky structure comprises:
depositing a front metal based on the surface of the barrier metal;
and etching the front metal to etch a preset pattern.
Optionally, the step of depositing a front metal based on the surface of the barrier metal comprises:
depositing one or more metals of Al, Ti, Ni and Ag based on the surface of the barrier metal.
Optionally, the step of growing a dielectric layer on the basis of the inner wall of the trench includes:
growing SiO on the inner wall based on the groove 2 And (3) a layer.
Compared with the prior art, the method has the following beneficial effects:
the method comprises the steps of etching a groove on an epitaxial layer by utilizing an imaging photoetching plate layer, growing a dielectric layer on the basis of the inner wall of the groove, depositing polycrystalline silicon along the surface of the epitaxial layer, oxidizing the polycrystalline silicon on the surface of the epitaxial layer to form an oxide layer, etching a contact hole on the basis of the oxide layer, exposing the groove, and depositing barrier metal and front metal on the basis of the contact hole to form the groove Schottky structure. According to the method, after the polycrystalline silicon is deposited, the polycrystalline silicon on the surface of the epitaxial layer is oxidized, so that the polycrystalline silicon on the surface of the epitaxial layer can be converted into the oxide layer for use, an additional oxide layer does not need to be deposited, the manufacturing process is simplified, and the manufacturing cost is saved.
In order to make the aforementioned objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and it will be apparent to those skilled in the art that other related drawings can be obtained from the drawings without inventive effort.
Fig. 1 is a schematic cross-sectional view corresponding to a first step of forming a trench schottky structure in the prior art.
Fig. 2 is a schematic cross-sectional view corresponding to a second step of forming a trench schottky structure in the prior art.
Fig. 3 is a schematic cross-sectional view illustrating a third step of fabricating a trench schottky structure according to the prior art.
Fig. 4 is a schematic cross-sectional view corresponding to a fourth step of fabricating a trench schottky structure in the prior art.
Fig. 5 is a schematic cross-sectional view illustrating a fifth step of fabricating a trench schottky structure in the prior art.
Fig. 6 is a schematic cross-sectional view illustrating a sixth step of fabricating a trench schottky structure according to the prior art.
Fig. 7 is a schematic cross-sectional view illustrating a seventh step of fabricating a trench schottky structure according to the prior art.
Fig. 8 is a schematic cross-sectional view illustrating an eighth step of fabricating a trench schottky structure according to the prior art.
Fig. 9 is a cross-sectional view illustrating a ninth step of fabricating a trench schottky structure according to the prior art.
Fig. 10 is an exemplary flowchart provided in an embodiment of the present application.
Fig. 11 is a schematic cross-sectional view of S104 in a method for fabricating a trench schottky structure according to an embodiment of the present disclosure.
Fig. 12 is a schematic cross-sectional view of S106 in a method for fabricating a trench schottky structure according to an embodiment of the present disclosure.
Fig. 13 is a schematic cross-sectional view of S108 in the method for fabricating a trench schottky structure according to the embodiment of the present application.
Fig. 14 is a schematic cross-sectional view of S110 in a method for fabricating a trench schottky structure according to an embodiment of the present disclosure.
Fig. 15 is a schematic cross-sectional view illustrating a barrier metal deposited in a method for fabricating a trench schottky structure according to an embodiment of the present disclosure.
Fig. 16 is a schematic cross-sectional view illustrating the front metal deposition in the method for fabricating a trench schottky structure according to the embodiment of the present disclosure.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Meanwhile, in the description of the present application, the terms "first", "second", and the like are used only for distinguishing the description, and are not to be construed as indicating or implying relative importance.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.
Some embodiments of the present application will be described in detail below with reference to the accompanying drawings. The embodiments described below and the features of the embodiments can be combined with each other without conflict.
As described in the background art, the prior art has the problems of high cost and complex process when performing poly-crystal etching.
For example, fig. 1-9 show schematic cross-sectional views of a prior art trench schottky product during fabrication. As shown in fig. 1, after an epitaxial layer is grown on a substrate, trenches need to be etched in the epitaxial layer for a trench schottky product. In the actual etching process, a mask layer is deposited firstly, then etching holes are formed in the mask layer, and trenches are etched in the epitaxial layer on the basis of the mask layer by using an etching process.
As shown in fig. 2, after the trench etching is completed, the mask layer on the epitaxial layer needs to be removed, and at this time, the epitaxial layer with the trench is formed. The epitaxial layer shown in the figure is provided with two trenches, but in practical application, the number of trenches is not limited, and for example, the number of trenches may be 6 or 8. In the prior art, when a mask layer is removed, watermarks are easily generated, and the performance of a manufactured groove Schottky product is influenced.
With reference to fig. 3, after the epitaxial layer with the trench is fabricated, a field plate oxide layer is grown on the surface of the epitaxial layer, wherein the field plate oxide layer is now located on the inner wall of the trench and the surface of the epitaxial layer. As shown in fig. 4, the polysilicon continues to grow, wherein the polysilicon grows by deposition and is located in the trench and on the surface of the epitaxial layer. It should be noted that, in order to ensure that the trenches are filled with polysilicon, the thickness of the polysilicon may be relatively thick when the polysilicon is grown.
Referring to fig. 5, after growing the polysilicon, the polysilicon on the surface of the epitaxial layer needs to be removed, i.e. the polysilicon on the surface of the epitaxial layer needs to be removed by a polysilicon planarization process. Generally, in the prior art, a Chemical Mechanical Polishing (CMP) process may be used for polycrystalline planarization, and a dry etching process may also be used for polycrystalline planarization, wherein the CMP process is a key process for implementing wafer surface planarization in an integrated circuit manufacturing process. Different from the traditional pure mechanical or pure chemical polishing method, the CMP process realizes the removal of micron/nanometer-scale different materials on the surface of the wafer by combining the technologies of surface chemical action and mechanical grinding, thereby achieving the nanometer-scale planarization of the surface of the wafer. The main working principle of CMP is that under a certain pressure and in the presence of polishing liquid, a polished wafer makes relative motion to a polishing pad, and the mechanical grinding action of nano-abrasive and the chemical action of various chemical reagents are highly organically combined, so that the surface of the polished wafer meets the requirements of high planarization, low surface roughness and low defect.
And the dry etching is a technique of performing thin film etching using plasma. When the gas is present in the form of a plasma, it has two characteristics: on one hand, the chemical activity of the gases in the plasma is much stronger than that of the gases in a normal state, and the gases can react with the materials more quickly by selecting proper gases according to the difference of the etched materials, so that the aim of etching removal is fulfilled; on the other hand, the electric field can be used for guiding and accelerating the plasma, so that the plasma has certain energy, and when the plasma bombards the surface of the etched object, atoms of the etched object material can be knocked out, thereby achieving the purpose of etching by using physical energy transfer. Thus, dry etching is a result of a balance of both physical and chemical processes on the wafer surface.
However, the CMP process requires a special grinding apparatus, while the dry etching process requires a dry etching apparatus, which is relatively expensive, and thus the production cost of the trench schottky product is high.
Referring to fig. 6, a dielectric layer, which may be SiO, is deposited on the surface of the epitaxial layer 2 The layer may be a nitride layer, and is not limited herein.
Continuing with fig. 7, the dielectric layer is etched to form the contact hole, and of course, the field plate oxide layer on the surface of the epitaxial layer is also etched away along with the dielectric layer.
With continued reference to fig. 8 and 9, to achieve schottky contact, barrier metal deposition continues along the surfaces of the epitaxial layers and dielectric layers. A schottky contact is formed between the barrier metal and the epitaxial layer. Meanwhile, in order to lead out the pin in the package, the front metal continues to grow on the surface of the barrier metal, and then the subsequent conventional manufacturing steps, such as the steps of manufacturing a passivation layer and the like, are continued to form the trench schottky product, which is not described herein again.
The conventional trench schottky product has a relatively mature manufacturing process, and the thickness of the dielectric layer can be adjusted at will. However, the whole process is relatively complex, the removal of hardmark after the trench etching is easy to generate watermark, a polycrystalline dry etching device is needed, a dielectric layer deposition device is needed, and the production cost of the trench schottky product is high.
In view of the above, in order to solve the above technical problems, the present application provides a method for fabricating a trench schottky structure, which achieves the effects of simplifying the process and reducing the production cost by oxidizing and then removing the polysilicon on the surface of the epitaxial layer.
The following is an exemplary description of a method for fabricating a trench schottky structure provided in the present application:
as an alternative implementation, referring to fig. 10, the method for fabricating the trench schottky structure includes:
and S102, etching a groove on the epitaxial layer by using the imaging photoetching plate layer.
And S104, growing a dielectric layer on the basis of the inner wall of the groove.
And S106, depositing polycrystalline silicon along the surface of the epitaxial layer, wherein the polycrystalline silicon is positioned on the surface of the epitaxial layer and in the groove.
And S108, oxidizing the polycrystalline silicon on the surface of the epitaxial layer to form an oxide layer.
S110, etching the contact hole based on the oxide layer and exposing the groove.
And S112, depositing barrier metal and front metal on the basis of the contact hole to form a trench Schottky structure.
Similar to the prior art, the processes of trench etching, dielectric layer growth and polycrystalline filling are also performed during the deposition of the polycrystalline silicon, which is not described herein again. Different from the prior art, the method has the advantages that after the groove is etched, the photoetching plate layer is not required to be removed, the polycrystalline silicon is directly deposited, and the photoetching plate layer is removed in the subsequent process. In the prior art, a wet etching process is generally adopted for removing the photoetching plate, so that compared with the prior art, the wet etching process is reduced at the moment, and the possibility of generating defects is further reduced. The dielectric layer provided in the present application may be an oxide layer or a nitride layer.
When the dielectric layer is an oxide layer, it may be SiO 2 And (3) a layer. And when the dielectric layer is manufactured, the dielectric layer is actually deposited along the surface of the epitaxial layer, and then the dielectric layer is etched. So as to form a dielectric layer connected with the inner wall of the groove, and the thickness of the dielectric layer is thinner.
Referring to fig. 11, after the dielectric layer is formed, the inner wall of the trench is connected to the dielectric layer, and the surface of the epitaxial layer is connected to the photolithography layer.
Polysilicon is deposited along the surface of the epitaxial layer at this point to form the structure shown in fig. 12, where the polysilicon is located within the trenches and on the surface of the epitaxial layer. And the surface of the epitaxial layer is also connected with a photoetching plate layer.
As shown in fig. 13, the polysilicon on the surface of the epitaxial layer is oxidized and an oxide layer is formed, so that in the subsequent process, no additional oxide layer needs to be deposited, the manufacturing process is simplified, and meanwhile, no oxide layer deposition equipment is needed, thereby achieving the effect of reducing the production cost.
In the oxidation process, the oxidation depth of the polysilicon needs to be controlled. As one implementation, all of the polysilicon on the surface of the epitaxial layer may be oxidized, and the polysilicon in the trench is not oxidized. As another implementation, all the polysilicon on the surface of the epitaxial layer and the polysilicon in the trench with a predetermined depth are oxidized. For example, in the oxidation process, the polysilicon with the depth of 500-600 angstroms on the surface where the trench and the epitaxial layer are flush can be simultaneously oxidized and can be adjusted according to actual requirements.
In other words, in order to prevent the polysilicon on the surface of the epitaxial layer from being not completely oxidized and affecting the subsequent etching process, it is necessary to ensure that the oxidation depth is greater than or equal to the thickness of the polysilicon on the surface of the epitaxial layer. Meanwhile, when the polycrystalline silicon on the surface of the epitaxial layer is removed, the polycrystalline silicon can be directly removed in a mode of removing the oxide layer, and the uniformity of polycrystalline removal and the accurate control of polycrystalline removal depth are improved.
Referring to fig. 14, the contact hole is continuously etched based on the oxide layer, and the trench is exposed. At the moment, only the oxide layer needs to be removed, and equipment for removing the polycrystalline silicon in the prior art is not needed, so that the process is simpler, and the cost is lower.
It should be noted that when the photolithography mask layer is made of SiO 2 In the case of layers, the oxide formed by the oxidation of the polysilicon is also SiO 2 Therefore, the step of etching the contact hole based on the oxide layer comprises the following steps:
and synchronously etching the oxide layer and the photoetching plate layer in the preset area to form a contact hole.
When the photoetching plate layer is non-SiO 2 During layer etching, the step of etching the contact hole based on the oxide layer at the moment comprises the following steps:
and etching the oxide layer in the preset area, and etching the photoetching plate layer to form the contact hole.
That is, if the oxide layer and the photoresist layer are made of the same material, the oxide layer and the photoresist layer can be removed together when the contact hole is etched. If the oxide layer and the photoetching plate layer are made of different materials, the oxide layer can be etched first when the contact hole is etched, and the photoetching plate layer can be etched.
As shown in fig. 15 and 16, a barrier metal and a front metal may be deposited in sequence based on the contact holes, wherein the barrier metal is used for schottky basis and the front metal is used as a package trace.
Optionally, in an actual process, S112 includes:
depositing a barrier metal based on the contact hole;
and etching the barrier metal to etch a preset pattern.
Then depositing a front metal based on the surface of the barrier metal;
and etching the front metal to etch a preset pattern.
And, the front metal may be one or more metals of Al, Ti, Ni and Ag.
It can be understood that the method for manufacturing the trench schottky structure provided by the present application has at least the following beneficial effects:
first, since the photoresist layer is not directly removed after the trench is etched using the photoresist layer, a wet etching process is reduced.
Secondly, the polycrystalline silicon can effectively control the polycrystalline retention depth and uniformity by adopting an oxidation process.
Third, the use of an oxidation process for the polysilicon can reduce polysilicon surface damage.
Fourthly, the oxidation process is used for the polycrystal, so that the etching of the polysilicon and the deposition of a dielectric layer can be reduced, the equipment investment and the production cost are further reduced, and the manufacturing process is simplified.
In summary, the present application provides a method for fabricating a trench schottky structure, which includes etching a trench on an epitaxial layer by using an image lithography plate layer, growing a dielectric layer on the inner wall of the trench, depositing polysilicon along the surface of the epitaxial layer, wherein the polysilicon is located on the surface of the epitaxial layer and in the trench, oxidizing the polysilicon located on the surface of the epitaxial layer to form an oxide layer, etching a contact hole on the basis of the oxide layer, exposing the trench, and depositing barrier metal and front metal on the basis of the contact hole to form the trench schottky structure. According to the method, after the polycrystalline silicon is deposited, the polycrystalline silicon on the surface of the epitaxial layer is oxidized, so that the polycrystalline silicon on the surface of the epitaxial layer can be converted into the oxide layer for use, an additional oxide layer does not need to be deposited, the manufacturing process is simplified, and the manufacturing cost is saved.
The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.
It will be evident to those skilled in the art that the present application is not limited to the details of the foregoing illustrative embodiments, and that the present application may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Claims (8)
1. A method for manufacturing a trench Schottky structure is characterized by comprising the following steps:
etching a groove on the epitaxial layer by using the imaging photoetching plate layer;
growing a dielectric layer on the basis of the inner wall of the groove;
depositing polycrystalline silicon along the surface of the epitaxial layer, wherein the polycrystalline silicon is positioned on the surface of the epitaxial layer and in the groove;
oxidizing the polycrystalline silicon on the surface of the epitaxial layer to form an oxide layer;
etching a contact hole based on the oxide layer and exposing a groove;
and depositing a barrier metal and a front metal based on the contact hole to form a trench Schottky structure.
2. The method of claim 1, wherein oxidizing polysilicon located on a surface of the epitaxial layer comprises:
oxidizing all the polycrystalline silicon on the surface of the epitaxial layer, wherein the polycrystalline silicon in the groove is not oxidized; or
And oxidizing all the polysilicon on the surface of the epitaxial layer and the polysilicon with the preset depth in the groove.
3. The method of claim 1, wherein the photolithographic layer is SiO 2 During layer etching, the step of etching the contact hole based on the oxide layer comprises the following steps of:
and synchronously etching the oxide layer and the photoetching plate layer in the preset area to form a contact hole.
4. The method of claim 1, wherein the photolithographic masking layer is non-SiO 2 During layer etching, the step of etching the contact hole based on the oxide layer comprises the following steps of:
and etching the oxide layer in the preset area, and etching the photoetching plate layer to form the contact hole.
5. The method of claim 1 wherein depositing a barrier metal and a front metal over the contact hole to form a trench schottky structure comprises:
depositing a barrier metal based on the contact hole;
and etching the barrier metal to etch a preset pattern.
6. The method of claim 1, wherein depositing a barrier metal and a front metal on the contact hole to form a trench schottky structure comprises:
depositing a front metal based on the surface of the barrier metal;
and etching the front metal to etch a preset pattern.
7. The method of fabricating a trench schottky structure of claim 6 wherein the step of depositing a front metal on the surface of the barrier metal comprises:
depositing one or more metals of Al, Ti, Ni and Ag based on the surface of the barrier metal.
8. The method of claim 1, wherein the step of growing a dielectric layer on the inner wall of the trench comprises:
growing SiO on the inner wall based on the groove 2 And (3) a layer.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115863413A (en) * | 2023-03-01 | 2023-03-28 | 通威微电子有限公司 | Method for manufacturing trench oxide layer and semiconductor device |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115863413A (en) * | 2023-03-01 | 2023-03-28 | 通威微电子有限公司 | Method for manufacturing trench oxide layer and semiconductor device |
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