CN114122041A - Image sensor, preparation method thereof and electronic equipment - Google Patents
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- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14683—Processes or apparatus peculiar to the manufacture or treatment of these devices or parts thereof
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- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/1463—Pixel isolation structures
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- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
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Abstract
The invention provides an image sensor, a preparation method thereof and an electronic device, wherein the image sensor comprises: a substrate in which at least two photoelectric conversion elements arranged at intervals are formed; a deep trench located between two adjacent photoelectric conversion elements in the substrate, the deep trench having a first width; the first spin-on dielectric material is filled at the bottom of the deep groove; the monocrystalline silicon layer is formed on the side wall of the deep groove, so that the width of the deep groove is reduced to a second width, and the second width is smaller than the first width; the high-K dielectric layers are formed at the bottom and the side walls of the deep groove; the second spin-on dielectric fills the deep trench. The invention greatly improves the depth-width ratio of the deep groove and simultaneously avoids the generation of holes when the deep groove is filled.
Description
Technical Field
The invention belongs to the field of image sensing, and particularly relates to an image sensor, a preparation method thereof and electronic equipment.
Background
With the shift of CIS (cmos IMAGE sensor) sensor chips from front-side illumination (FSI) to back-side illumination (BSI) and stacked (stacked) technologies, the market application scenarios of CIS IMAGE sensor chips are becoming wider. CIS image sensor chips tend to have higher pixels and smaller pixel sizes, which have been scaled down from 1.75 microns for front-side to 1.12 microns for back-side, and even to 0.7 microns for back-side.
As the size of the pixels of a backside illuminated (BSI) CIS image sensor gradually decreases, the isolated regions between the pixels also decrease simultaneously, gradually from 0.5 micron to around 0.2 micron and even smaller. Meanwhile, for a high-end process, a Photodiode (PD) is thicker and thicker so as to absorb more photons and convert the photons into an electric signal, the etching depth of a deep groove (DTI) reaches more than 5 micrometers, the depth-to-width ratio reaches more than 25, and higher requirements are put forward for the process. Under such a technical requirement, there are two problems: 1) the ability of the etcher station to achieve such high aspect ratios is difficult. 2) The insulating medium filled in the deep trench still generates voids (void), thereby affecting the electrical isolation performance.
It should be noted that the above background description is only for the convenience of clear and complete description of the technical solutions of the present application and for the understanding of those skilled in the art. Such solutions are not considered to be known to the person skilled in the art merely because they have been set forth in the background section of the present application.
Disclosure of Invention
In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide an image sensor, a method for manufacturing the same, and an electronic device, which are used to solve the problems in the prior art that a deep trench is difficult to realize a high aspect ratio and a deep trench filling is easy to generate a void.
To achieve the above and other related objects, the present invention provides a method for manufacturing an image sensor, the method comprising the steps of: 1) providing a substrate, wherein at least two photoelectric conversion elements are formed in the substrate at intervals; 2) etching a deep groove between two adjacent photoelectric conversion elements in the substrate, wherein the deep groove has a first width; 3) forming a first spin-on dielectric material on the substrate by a first spin-on process, filling the first spin-on dielectric material into the bottom of the deep trench by utilizing the flowability of the first spin-on dielectric material, and curing the first spin-on dielectric material; 4) selectively extending a monocrystalline silicon layer on the side wall of the deep groove to reduce the width of the deep groove to a second width, wherein the second width is smaller than the first width; 5) forming a high-K dielectric layer at the bottom and the side wall of the deep groove; 6) and forming a second spin-on dielectric material on the substrate by a second spin-on process, filling the deep groove with the second spin-on dielectric material by utilizing the flowability of the second spin-on dielectric material, and curing the second spin-on dielectric material.
Optionally, step 2) comprises: 2-1) forming a hard mask layer on the substrate; 2-2) forming a photoresist layer on the hard mask layer, and carrying out exposure and development processes on the photoresist layer to form a photoetching pattern; 2-3) etching the hard mask layer based on the photoetching pattern to form an etching window; 2-4) etching the deep groove in the substrate through the etching window; 2-5) removing the photoetching pattern and reserving the hard mask layer.
Optionally, the hard mask layer is made of silicon dioxide, and the thickness of the hard mask layer is 100-200 angstroms.
Optionally, in step 4), the sidewall of the hard mask layer does not extend out of the monocrystalline silicon layer, so that after the selective extension of the monocrystalline silicon layer on the sidewall of the deep trench, the opening width of the hard mask layer at the deep trench is greater than the second width of the deep trench.
Optionally, after the width of the deep trench is reduced to the second width, the aspect ratio of the deep trench is greater than or equal to 30.
Optionally, the depth of the deep groove is greater than or equal to 5 micrometers, and the first width of the deep groove is 140 nanometers to 260 nanometers.
Optionally, in the step 4), the thickness of the selectively epitaxial monocrystalline silicon layer on the side wall of the deep trench is 20 nm to 50 nm, so that the width of the deep trench is reduced to a second width, and the second width is 100 nm to 160 nm.
Optionally, in step 5), an atomic layer deposition process is adopted to form a high-K dielectric layer at the bottom and the side wall of the deep trench.
Optionally, a step 7) of performing a chemical mechanical polishing process on the substrate to remove the second spin-on dielectric material and the high-K dielectric layer on the surface of the substrate is further included.
Optionally, the thickness of the first spin-on dielectric material is one tenth to one fifth of the depth of the deep trench.
Optionally, the first and second spin-on dielectrics are in a liquid state before curing, the spin-on dielectrics are dispersed on the surface of the substrate under the centrifugal force generated by the rotation of the substrate, and the spin-on dielectrics on the deep trench flow and fill in the deep trench under the action of gravity.
The present invention also provides an image sensor, including: a substrate in which at least two photoelectric conversion elements arranged at intervals are formed; a deep trench located between two adjacent photoelectric conversion elements in the substrate, the deep trench having a first width; the first spin-on dielectric material is filled at the bottom of the deep groove; the monocrystalline silicon layer is formed on the side wall of the deep groove, so that the width of the deep groove is reduced to a second width, and the second width is smaller than the first width; the high-K dielectric layers are formed at the bottom and the side walls of the deep groove; and a second spin-on dielectric material filling the deep trench.
Optionally, the surface of the substrate is further provided with a hard mask layer, the hard mask layer is made of silicon dioxide, the thickness of the hard mask layer is 100-200 angstroms, and the opening width of the hard mask layer at the deep groove is larger than the second width of the deep groove.
Optionally, the depth of the deep trench is greater than or equal to 5 micrometers, the first width of the deep trench is between 140 nanometers and 260 nanometers, the thickness of the monocrystalline silicon layer on the side of the deep trench is between 20 nanometers and 50 nanometers, and the deep trench is narrowed to a second width, which is between 100 nanometers and 160 nanometers.
Optionally, the thickness of the first spin-on dielectric material is one tenth to one fifth of the depth of the deep trench.
Optionally, after the width of the deep trench is reduced to the second width, the aspect ratio of the deep trench is greater than or equal to 30.
The invention also provides an electronic device, which comprises the image sensor according to any one of the above aspects.
As described above, the image sensor, the manufacturing method thereof, and the electronic device according to the present invention have the following advantageous effects:
according to the invention, after a deep groove structure with a larger width is etched, the width of the deep groove is reduced by a method of extending monocrystalline silicon, so that the depth-to-width ratio of the deep groove is greatly improved under the condition of greatly reducing the difficulty of the deep groove etching process, the depth-to-width ratio of the deep groove can reach more than 30, the distance between photoelectric conversion elements of an image sensor can be effectively increased, the effective area of the photoelectric conversion elements is increased, and the photoelectric conversion efficiency of the image sensor is improved.
According to the invention, the deep groove is filled by the method for preparing the spin-on dielectric material by the spin coating process, and the filling capacity of the dielectric material is greatly improved by the fluidity and the flatness of the spin-on dielectric material, so that the generation of holes during the filling of the deep groove is avoided, the subsequent planarization process is facilitated, and the process stability is greatly improved.
Drawings
The accompanying drawings, which are included to provide a further understanding of the embodiments of the application, are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. It is to be understood that the drawings in the following description are of some embodiments of the application only.
Fig. 1 to 7 are schematic structural diagrams of steps of a method for manufacturing an image sensor according to an embodiment of the invention, wherein fig. 7 is a schematic structural diagram of an image sensor according to an embodiment of the invention.
The device label shows 101 a substrate, 102 a photoelectric conversion device, 103 a transistor, 104 a hard mask layer, 105 a deep trench, 106 a first spun-on dielectric material, 107 a single crystal silicon layer, 108 a high-K dielectric layer, 109 a second spun-on dielectric material.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.
It should be emphasized that the term "comprises/comprising" when used herein, is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps or components.
Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments, in combination with or instead of the features of the other embodiments.
As in the detailed description of the embodiments of the present invention, the cross-sectional views illustrating the device structures are not partially enlarged in general scale for convenience of illustration, and the schematic views are only examples, which should not limit the scope of the present invention. In addition, the three-dimensional dimensions of length, width and depth should be included in the actual fabrication.
For convenience in description, spatial relational terms such as "below," "beneath," "below," "under," "over," "upper," and the like may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that these terms of spatial relationship are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the figures. Further, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.
In the context of this application, a structure described as having a first feature "on" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed in between the first and second features, such that the first and second features may not be in direct contact.
It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the drawings only show the components related to the present invention rather than being drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of each component in actual implementation may be changed arbitrarily, and the layout of the components may be more complicated.
As shown in fig. 1 to 7, the present embodiment provides a method for manufacturing an image sensor, including the following steps:
as shown in fig. 1, step 1) is performed first, a substrate 101 is provided, and at least two photoelectric conversion elements 102 arranged at intervals are formed in the substrate 101.
As shown in fig. 1, the material of the substrate 101 may be silicon, silicon germanium, a iii-v compound, etc., and in this embodiment, the material of the substrate 101 is silicon.
As shown in fig. 1, the substrate 101 includes a first main surface and a second main surface opposite to each other, the first main surface may be further fabricated with a transistor 103 required by an image sensor, such as a transfer transistor, a reset transistor, a source follower transistor, a row selection transistor, and the like, and the above-listed examples are not limited thereto, at least two photoelectric conversion elements 102 are formed in the substrate 101 at intervals, the photoelectric conversion elements 102 may be photodiodes, for example, and in order to avoid the influence of the deep trench 105 process on the transistor 103, in this embodiment, the deep trench 105 is etched from the back surface (the second main surface) after the substrate 101 is inverted, and the second main surface is relatively flat (no device structure), so that the deep trench 105 etching process can be facilitated.
As shown in fig. 2, step 2) is then performed to etch a deep trench 105 between two adjacent photoelectric conversion elements 102 in the substrate 101, where the deep trench 105 has a first width.
In one embodiment, step 2) comprises:
step 2-1), forming a hard mask layer 104 on the substrate 101; the hard mask layer 104 may be made of silicon dioxide, and in other embodiments, the hard mask layer 104 may also be made of silicon nitride, silicon oxynitride, or the like, or a stack of the above materials. The hard mask layer 104 may have a thickness of 100-200 angstroms. In one embodiment, the hard mask layer 104 has a thickness of 150 angstroms.
And 2-2), forming a photoresist layer on the hard mask layer 104, and carrying out exposure and development processes on the photoresist layer to form a photoetching pattern.
Step 2-3), etching the hard mask layer 104 based on the photoetching pattern to form an etching window; for example, the hard mask layer 104 may be etched by a dry etching process such as ICP etching.
Step 2-4), etching the deep groove 105 in the substrate 101 through the etching window; for example, the deep trench 105 may be etched in the substrate 101 by using an ICP deep silicon etching process, where a depth of the deep trench 105 is greater than or equal to 5 micrometers, and a first width of the deep trench 105 is between 140 nanometers and 260 nanometers.
2-5) removing the photoetching pattern and reserving the hard mask layer 104. For example, the lithographic pattern may be removed using an oxygen plasma.
As shown in fig. 3, step 3) is then performed to form a first Spin-on dielectric (SOD) 106 on the substrate 101 by a first Spin-on process, fill the first Spin-on dielectric 106 into the bottom of the deep trench 105 by utilizing the flowability of the first Spin-on dielectric 106, and cure the first Spin-on dielectric 106, wherein the curing process may be, for example, thermal curing, and the cured first Spin-on dielectric 106 may be silicon dioxide.
The first spun-on dielectric material 106 may comprise a dielectric material such as silicon dioxide, which is liquid during the spin-on process and has a strong flowability, and can flow from the surface of the substrate 101 to the bottom of the deep trench 105 under the action of gravity.
In one embodiment, the first spun-on dielectric material 106 is in a liquid state before curing, and is dispersed on the surface of the substrate 101 under the centrifugal force generated by the rotation of the substrate 101, and the spun-on dielectric material on the deep trench 105 flows and fills the deep trench 105 under the action of gravity.
In one embodiment, the thickness of the first spun-on dielectric material 106 is one tenth to one fifth of the depth of the deep trench 105. For example, the thickness of the first spin-on dielectric material 106 may be 500 nm to 1000 nm.
As shown in fig. 4, step 4) is then performed to selectively epitaxially grow a single crystal silicon layer 107 on the sidewall of the deep trench 105, so that the width of the deep trench 105 is reduced to a second width, which is smaller than the first width.
In one embodiment, in step 4), the sidewall of the hard mask layer 104 does not extend the single crystal silicon layer 107, so that after the deep trench 105 sidewall is selectively extended by the single crystal silicon layer 107, the opening width of the hard mask layer 104 at the deep trench 105 is greater than the second width of the deep trench 105, and the opening of the hard mask layer 104 at the deep trench 105 and the deep trench 105 form a "funnel-shaped" structure, thereby facilitating the subsequent filling of the deep trench 105 with the second spin-on dielectric material 109.
In one embodiment, the aspect ratio of the deep trench 105 is greater than or equal to 30 after the width of the deep trench 105 is reduced to a second width by the epitaxial single crystal silicon layer 107 selective to the sidewalls of the deep trench 105.
In one embodiment, the thickness of the epitaxial single crystal silicon layer 107 on the sidewall of the deep trench 105 in step 4) is between 20 nm and 50 nm, so that the width of the deep trench 105 is reduced to a second width, and the second width is between 100 nm and 160 nm.
As shown in fig. 5, step 5) is performed to form a high-K dielectric layer 108 on the bottom and sidewalls of the deep trench 105.
In one embodiment, in step 5), an atomic layer deposition process is used to form the high-K dielectric layer 108 on the bottom and the sidewall of the deep trench 105, so as to improve the filling capability and the thickness uniformity of the filling of the high-K dielectric layer 108. The material of the high-K dielectric layer 108 may be HfO2、HfTiO、HfSiON、Al2O3、ZrO2And the high-K dielectric layer 108 can effectively improve the isolation effect between two adjacent photoelectric conversion elements 102.
As shown in fig. 6, step 6) is then performed to form a second spun-on dielectric material 109 on the substrate 101 by a second spin-on process, fill the deep trench 105 with the flowable second spun-on dielectric material 109, and cure the second spun-on dielectric material 109. The curing process may be, for example, thermal curing, and the second spun-on dielectric material 109 after curing may be silicon dioxide.
In one embodiment, the second spun-on dielectric material 109 is in a liquid state before curing, and is dispersed on the surface of the substrate 101 by the centrifugal force generated by the rotation of the substrate 101, and the spun-on dielectric material on the deep trench 105 flows and fills the deep trench 105 under the action of gravity. The filling of the second spun-on dielectric material 109 may be facilitated by the "funnel" structure formed as described above.
As shown in fig. 7, finally, step 7) is performed to perform a chemical mechanical polishing process on the substrate 101 to remove the second spun-on dielectric material 109 and the high-K dielectric layer 108 on the surface of the substrate 101.
In one embodiment, the substrate 101 may be subjected to a chemical mechanical polishing process using a chemical mechanical polishing process CMP.
As shown in fig. 7, the present embodiment also provides an image sensor including: a substrate 101 in which at least two photoelectric conversion elements 102 arranged at intervals are formed; a deep trench 105 located between two adjacent photoelectric conversion elements 102 in the substrate 101, the deep trench 105 having a first width; a first spin-on dielectric material 106 filled at the bottom of the deep trench 105; a monocrystalline silicon layer 107 formed on the sidewall of the deep trench 105 to narrow the width of the deep trench 105 to a second width smaller than the first width; a high-K dielectric layer 108 formed on the bottom and the side wall of the deep trench 105; a second spun-on dielectric 109 fills the deep trench 105.
In one embodiment, the surface of the substrate 101 further has a hard mask layer 104, the hard mask layer 104 is made of silicon dioxide, the thickness of the hard mask layer 104 is 100-200 angstroms, and the opening width of the hard mask layer 104 at the deep trench 105 is greater than the second width of the deep trench 105.
In one embodiment, the depth of the deep trench 105 is greater than or equal to 5 μm, the first width of the deep trench 105 is between 140 nm and 260 nm, the thickness of the single crystal silicon layer 107 on the side of the deep trench 105 is between 20 nm and 50 nm, and the deep trench 105 is narrowed to a second width, the second width is between 100 nm and 160 nm.
In one embodiment, the thickness of the first spun-on dielectric material 106 is one tenth to one fifth of the depth of the deep trench 105.
In one embodiment, the aspect ratio of the deep trench 105 is greater than or equal to 30 after the width of the deep trench 105 is reduced to the second width.
The embodiment also provides an electronic device, which includes the image sensor according to any one of the above aspects. The electronic device can be a camera and the like, and can also be a mobile phone, a tablet personal computer, an unmanned aerial vehicle, a robot, a new energy automobile and the like which comprise the camera.
As described above, the image sensor, the manufacturing method thereof, and the electronic device according to the present invention have the following advantageous effects:
according to the invention, after the deep groove 105 structure with a larger width is etched, the width of the deep groove 105 is reduced by a method of extending monocrystalline silicon, so that the depth-to-width ratio of the deep groove 105 is greatly improved under the condition of greatly reducing the difficulty of the etching process of the deep groove 105, the depth-to-width ratio of the deep groove 105 can reach more than 30, the distance between photoelectric conversion elements 102 of an image sensor can be effectively increased, the effective area of the photoelectric conversion elements 102 is increased, and the photoelectric conversion efficiency of the image sensor is improved.
According to the invention, the deep groove 105 is filled by the method for preparing the spin-on dielectric material by the spin coating process, and the filling capacity of the dielectric material is greatly improved by the fluidity and the flatness of the spin-on dielectric material, so that the generation of holes during filling the deep groove 105 is avoided, the subsequent planarization process is facilitated, and the process stability is greatly improved.
Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.
Claims (17)
1. A method of manufacturing an image sensor, the method comprising the steps of:
1) providing a substrate, wherein at least two photoelectric conversion elements are formed in the substrate at intervals;
2) etching a deep groove between two adjacent photoelectric conversion elements in the substrate, wherein the deep groove has a first width;
3) forming a first spin-on dielectric material on the substrate by a first spin-on process, filling the first spin-on dielectric material into the bottom of the deep trench by utilizing the flowability of the first spin-on dielectric material, and curing the first spin-on dielectric material;
4) selectively extending a monocrystalline silicon layer on the side wall of the deep groove to reduce the width of the deep groove to a second width, wherein the second width is smaller than the first width;
5) forming a high-K dielectric layer at the bottom and the side wall of the deep groove;
6) and forming a second spin-on dielectric material on the substrate by a second spin-on process, filling the deep groove with the second spin-on dielectric material by utilizing the flowability of the second spin-on dielectric material, and curing the second spin-on dielectric material.
2. The method for manufacturing an image sensor according to claim 1, wherein: the step 2) comprises the following steps:
2-1) forming a hard mask layer on the substrate;
2-2) forming a photoresist layer on the hard mask layer, and carrying out exposure and development processes on the photoresist layer to form a photoetching pattern;
2-3) etching the hard mask layer based on the photoetching pattern to form an etching window;
2-4) etching the deep groove in the substrate through the etching window;
2-5) removing the photoetching pattern and reserving the hard mask layer.
3. The method for manufacturing an image sensor according to claim 2, wherein: the hard mask layer is made of silicon dioxide, and the thickness of the hard mask layer is 100-200 angstroms.
4. The method for manufacturing an image sensor according to claim 2, wherein: in the step 4), the side wall of the hard mask layer does not extend to the monocrystalline silicon layer, so that after the selective extension of the monocrystalline silicon layer on the side wall of the deep groove, the opening width of the hard mask layer at the deep groove is larger than the second width of the deep groove.
5. The method for manufacturing an image sensor according to claim 1, wherein: and after the width of the deep groove is reduced to the second width, the depth-to-width ratio of the deep groove is greater than or equal to 30.
6. The method for manufacturing an image sensor according to claim 1, wherein: the depth of the deep groove is greater than or equal to 5 micrometers, and the first width of the deep groove is 140-260 nanometers.
7. The method for manufacturing an image sensor according to claim 6, wherein: and 4) reducing the width of the deep groove to a second width within the range of 100-160 nanometers when the thickness of the selective epitaxial monocrystal silicon layer on the side wall of the deep groove is within the range of 20-50 nanometers.
8. The method for manufacturing an image sensor according to claim 1, wherein: and 5) forming a high-K dielectric layer at the bottom and the side wall of the deep groove by adopting an atomic layer deposition process.
9. The method for manufacturing an image sensor according to claim 1, wherein: and 7) carrying out a chemical mechanical polishing process on the substrate to remove the second spin-on dielectric material and the high-K dielectric layer on the surface of the substrate.
10. The method for manufacturing an image sensor according to claim 1, wherein: the thickness of the first spin-on dielectric material is one tenth to one fifth of the depth of the deep groove.
11. The method for manufacturing an image sensor according to claim 1, wherein: the first spin-on dielectric material and the second spin-on dielectric material are in liquid state before solidification, the spin-on dielectric material is dispersed on the surface of the substrate under the centrifugal force generated by the rotation of the substrate, and the spin-on dielectric material on the deep groove flows and is filled in the deep groove under the action of gravity.
12. An image sensor, comprising:
a substrate in which at least two photoelectric conversion elements arranged at intervals are formed;
a deep trench located between two adjacent photoelectric conversion elements in the substrate, the deep trench having a first width;
the first spin-on dielectric material is filled at the bottom of the deep groove;
the monocrystalline silicon layer is formed on the side wall of the deep groove, so that the width of the deep groove is reduced to a second width, and the second width is smaller than the first width;
the high-K dielectric layers are formed at the bottom and the side walls of the deep groove;
and a second spin-on dielectric material filling the deep trench.
13. The image sensor of claim 12, wherein: the surface of the substrate is further provided with a hard mask layer, the hard mask layer is made of silicon dioxide, the thickness of the hard mask layer is 100-200 angstroms, and the opening width of the hard mask layer at the deep groove is larger than the second width of the deep groove.
14. The image sensor of claim 12, wherein: the depth of the deep groove is larger than or equal to 5 micrometers, the first width of the deep groove is 140 nanometers-260 nanometers, the thickness of the monocrystalline silicon layer on the deep groove side is 20 nanometers-50 nanometers, the deep groove is reduced to a second width, and the second width is 100 nanometers-160 nanometers.
15. The image sensor of claim 12, wherein: the thickness of the first spin-on dielectric material is one tenth to one fifth of the depth of the deep groove.
16. The image sensor of claim 12, wherein: and after the width of the deep groove is reduced to the second width, the depth-to-width ratio of the deep groove is greater than or equal to 30.
17. An electronic device, characterized in that the electronic device comprises an image sensor according to any one of claims 12 to 16.
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| US20140353468A1 (en) * | 2013-05-31 | 2014-12-04 | SK Hynix Inc. | Isolation structure and method for forming the same, and image sensor including the isolation structure and method for fabricating the image sensor |
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| US20140353468A1 (en) * | 2013-05-31 | 2014-12-04 | SK Hynix Inc. | Isolation structure and method for forming the same, and image sensor including the isolation structure and method for fabricating the image sensor |
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