Detection chip and preparation method thereof

Abstract

The invention provides a detection chip and a preparation method thereof, and the detection chip comprises a substrate which is provided with a detection region and a lead-out region surrounding the detection region; an isolation layer covering the surface of the substrate; the conductive structure layer is located on the isolation layer and comprises a plurality of conductive channels which are arranged on the detection area and communicated in a staggered mode and two extraction electrodes which are arranged on the extraction area and connected with the conductive channels, and a groove is formed between every two adjacent conductive channels; the insulating layer covers the isolating layer and the conductive structure layer, an accommodating cavity is formed in the detection area to expose the conductive channel and the groove, and the accommodating cavity is used for loading a fluid sample; and the at least two contact electrodes are arranged in the insulating layer on the leading-out area and are connected with the leading-out electrodes. According to the invention, the conductive channels are communicated in the detection area in a staggered manner to form the grooves, and the side walls of the conductive channels are exposed by using the grooves, so that the contact area between the outer walls of the conductive channels and the flowing sample is obviously increased, and the detection precision is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and particularly to a detection chip and a preparation method thereof. Background Art

[0002] Currently, the basic principle of performing in vitro detection for trace molecule or signal detection is to utilize specific groups on the structure of the molecule to be detected, find molecules that can specifically bind or react with it, and obtain the concentration information of the sample to be detected through the color change of the product after the combination or reaction of the two or the change in the fluorescence intensity that can be emitted.

[0003] The above method is based on the optical principle and is limited by the property changes of the product after the reaction between the sample to be detected and the test reagent. If the color or fluorescence intensity of the product changes little, the test accuracy of this method will be greatly affected. To expand the application range of this method, the current common practice is to label fluorescent molecules on the test reagent, wash away the unreacted reagent after the reaction between the test reagent and the sample to be detected, and then calculate the concentration of the molecule to be detected by detecting the intensity of the fluorescence.

[0004] However, the above test method has the following problems: a. The test process is complex. The method of using absorbance or fluorescence intensity change to detect the molecule concentration is usually carried out with a microplate. First, the test reagent needs to be embedded on the microplate, then the sample to be detected is prepared (since the detection concentration range requires the sample to be detected to be diluted in advance, etc.), and incubated under specific conditions, and then the product after the reaction is processed, and finally it can be detected by an absorbance or fluorescence detection device; b. The sample preparation conditions are harsh. First, the volume of each sample well of the microplate used is limited (≤0.25 ml), and whether adding or removing the sample, a micropipette needs to be used; furthermore, after the sample is mixed in the microplate, it usually needs to be incubated in a specific environment for a period of time, and even needs to be in a shaker to make the reaction between the sample to be detected and the test reagent uniform; in addition, limited by the properties of some components, it may be necessary to avoid light throughout the process and complete the test within a short time limit, with high requirements for operation accuracy. c. The result accuracy varies greatly. Due to the complex sample preparation and test process, harsh conditions, and high requirements for the operator, any non-standard or error in the above links will cause inaccurate results. In addition, the measurement accuracy of the optical test method itself is limited and cannot meet the accurate test of trace molecules. Summary of the Invention

[0005] The purpose of the present invention is to provide a detection chip and a preparation method thereof to improve the detection accuracy and detection efficiency.

[0006] To solve the above technical problems, the detection chip provided by the present invention is used to detect fluid samples and includes:

[0007] A substrate, having a detection region and a lead-out region surrounding the detection region;

[0008] An isolation layer, covering the surface of the substrate;

[0009] A conductive structure layer, located on the isolation layer, including a plurality of intersecting and communicating conductive channels provided on the detection region, and two lead-out electrodes provided on the lead-out region and connected to the conductive channels, and a groove is formed between adjacent conductive channels;

[0010] An insulating layer, covering the isolation layer and the conductive structure layer, and forming a receiving cavity on the detection region to expose the conductive channels and the grooves, and the receiving cavity is used for loading the fluid sample;

[0011] At least two contact electrodes, provided in the insulating layer on the lead-out region, and electrically leading out the two lead-out electrodes.

[0012] Optionally, the conductive channels are fin-shaped, a plurality of the conductive channels are in a criss-cross grid shape, and the grooves are rectangular.

[0013] Optionally, the detection region is rectangular, and the two lead-out electrodes are provided on opposite sides of the detection region, and the conductive channels are led out from both sides of the detection region.

[0014] Optionally, part of the lead-out electrodes also extend into the detection region.

[0015] Optionally, contact holes exposing the lead-out electrodes are formed in the insulating layer on the lead-out region, and the contact electrodes cover the inner walls of the contact holes to be concave, or the contact electrodes fill the contact holes to the surface of the insulating layer to be columnar.

[0016] Optionally, two contact electrodes are provided on each lead-out electrode, and the two contact electrodes provided on the two lead-out electrodes are used to apply a constant current to the detection region, and the remaining two contact electrodes are used to test the voltage at both ends of the detection region.

[0017] Optionally, a detection film layer is further provided on the outer wall of the conductive channels exposed in the receiving cavity, and the detection film layer is used for detection in an opposite manner to the fluid sample.

[0018] Based on another aspect of the present invention, a method for manufacturing a detection chip is further provided, including:

[0019] Providing a substrate, which has a detection region and a lead-out region surrounding the detection region;

[0020] Forming an isolation layer and a conductive material layer, the isolation layer covering the substrate, and the conductive material layer covering the isolation layer;

[0021] A patterning process is performed on the conductive material layer to form a conductive structure layer, the conductive structure layer including a plurality of intersecting and communicating conductive channels provided on the detection area, and two lead electrodes provided on the lead-out area and connected to the conductive channels, with grooves formed between adjacent conductive channels;

[0022] An insulating layer is formed to cover the isolation layer and the conductive structure layer, at least two contact electrodes are formed in the insulating layer on the lead-out area to electrically lead out the two lead electrodes, and the insulating layer in the detection area is removed to form a receiving cavity to expose the conductive channels and the grooves.

[0023] Optionally, the material of the conductive material layer includes polysilicon, and the steps of forming the contact electrodes include:

[0024] After forming the conductive structure layer, ion implantation is performed on the lead electrodes, and metal silicide is formed on the surface of part of the lead electrodes, and then an insulating barrier layer is formed to cover the outer wall of the conductive structure layer and the surface of the isolation layer.

[0025] An insulating material layer is formed to cover the isolation layer and the conductive structure layer and is filled above the conductive structure layer;

[0026] A patterning process is performed on the insulating material layer to form contact holes in the insulating material layer on the lead-out area to expose the metal silicide on the lead electrodes;

[0027] A metal barrier layer and a metal material layer are sequentially formed to cover the inner wall of the contact holes and the surface of the insulating material layer;

[0028] The metal barrier layer and the metal material layer outside the contact holes are removed, and the metal barrier layer and the metal material layer in the contact holes are used as the contact electrodes.

[0029] Optionally, the steps of forming the receiving cavity include:

[0030] A patterned mask is formed to cover the insulating material layer and the contact electrodes on the lead-out area, and the opening of the patterned mask exposes the insulating material layer in the detection area;

[0031] Using the patterned mask, an etching process is performed to sequentially remove the insulating material layer and the insulating barrier layer in the detection area to form the receiving cavity, expose the conductive channels and the grooves, and use the remaining insulating material layer as the insulating layer.

[0032] In summary, the detection chip provided by the present invention is provided with a conductive structure layer, an insulating layer and a contact electrode on the isolation layer of the substrate, the conductive structure layer includes a nanometer-scale conductive channel arranged on the detection area, and two extraction electrodes arranged on the extraction area connected to the conductive channel, a groove is formed between adjacent conductive channels, the insulating layer covers the isolation layer and the conductive structure layer, and a receiving cavity is formed on the detection area to expose the conductive channel and the groove, and the contact electrode is arranged in the insulating layer on the extraction area and connected to the extraction electrode. Compared with the optical method used in the related art to detect biological signals, this embodiment combines chip technology with biological detection, and the detection chip prepared by CMOS technology has highly identical specifications, which can effectively reduce the adverse effects of each process deviation in the related art on the final detection result, and can also reduce the corresponding detection cost. Moreover, when the above-mentioned detection chip is used to detect fluid samples (biological samples), high automation can be achieved in both sample loading and detection links, reducing the requirements for environmental conditions, and optimizing the sample preparation link to reduce manual operation, which not only makes the entire detection process (including loading samples and detecting samples) more efficient, but also avoids errors introduced by manual participation. In addition, in the above detection chip, the conductive channels are interconnected in the detection area and grooves are formed between adjacent conductive channels. The grooves are used to expose the side walls of the conductive channels to significantly increase the contact area between the outer walls of the conductive channels and the flowing sample, thereby improving the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Those skilled in the art should understand that the drawings are provided for a better understanding of the present invention, but do not constitute any limitation on the scope of the present invention.

[0034] Figure 1 is a flow chart of the method for preparing the detection chip provided in Example 1;

[0035] Figure 2a ˉ Figure 2k A schematic diagram of the structures corresponding to the corresponding steps of the method for preparing the detection chip provided in Example 1;

[0036] Figure 2l and Figure 2m A schematic diagram of a detection chip provided for implementation of the first and second embodiments;

[0037] Figure 3a , Figure 3b Figure 3c and Figure 3d This is a schematic diagram of four detection chips provided in Example 3.

[0038] In the attached figure:

[0039] 10 - Substrate; 11 - Isolation layer; AA - Detection area; BB - Lead - out area; 21 - Conductive material layer; 22 - First electrode; 23 - Second electrode; 22a - First lead - out part; 22b - First electrode part; 23a - Second lead - out part; 23b - Second electrode part; 24 - Conductive channel; 25 - Groove; 26 - Insulating barrier layer; 27a - Insulating material layer; 27 - Insulating layer; 31 - Contact hole; 31a - First contact hole; 31b - Second contact hole; 31c - Third contact hole; 31d - Fourth contact hole; 321 - Metal material layer; 32 - Contact electrode; 32a - First contact electrode; 32b - Second contact electrode; 32c - Third contact electrode; 32d - Fourth contact electrode; 33 - Patterned mask; 34 - Accommodating cavity. Detailed implementation manners

[0040] To make the objectives, advantages and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the accompanying drawings are in very simplified forms and are not drawn to scale, and are only used to facilitate and clearly assist in explaining the objectives of the embodiments of the present invention. In addition, the structures shown in the accompanying drawings are often part of the actual structures. In particular, the focus to be shown in each accompanying drawing is different, and sometimes different scales are used.

[0041] As used in the present invention, the singular forms "a", "an" and "the" include plural objects, the term "or" is generally used in the sense of including "and / or", the term "several" is generally used in the sense of including "at least one", the term "at least two" is generally used in the sense of including "two or more", in addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", "third" may explicitly or implicitly include one or at least two of such features, unless the content clearly indicates otherwise.

[0042] Embodiment 1

[0043] Embodiment 1 provides a method for preparing a detection chip.

[0044] Figure 1 is a flowchart of the method for preparing the detection chip provided in Embodiment 1.

[0045] As Figure 1 shown, the method for preparing the detection chip provided in this embodiment includes:

[0046] S01: Provide a substrate having a detection area and a lead - out area surrounding the detection area;

[0047] S02: Form an isolation layer and a conductive material layer, where the isolation layer covers the substrate and the conductive material layer covers the isolation layer;

[0048] S03: Perform a patterning process on the conductive material layer to form a conductive structure layer. The conductive structure layer includes a plurality of intersecting and communicating conductive channels provided on the detection area, and two lead electrodes connected to the conductive channels and provided on the lead-out area. A groove is formed between adjacent conductive channels;

[0049] S04: Form an insulating layer to cover the isolation layer and the conductive structure layer, form at least two contact electrodes in the insulating layer on the lead-out area to electrically lead out the two lead electrodes, and remove the insulating layer in the detection area to form a receiving cavity to expose the conductive channels and the grooves.

[0050] Figure 2a ˉ Figure 2m FIG. is a schematic structural diagram corresponding to the corresponding steps of the preparation method of the detection chip provided in Embodiment 1. Next, it will be described in detail in conjunction with Figure 2a ˉ Figure 2m the preparation method of the detection chip.

[0051] First, please refer to Figure 2a , and perform step S01 to provide a substrate 10, which has a detection area AA and a lead-out area BB surrounding the detection area AA.

[0052] The material of the substrate 10 may include any suitable substrate material well-known to those skilled in the art. For example, it may be at least one of the materials mentioned below: silicon, glass, quartz, plastic, etc.

[0053] The detection area AA is used to form a detection film layer and form a corresponding electrical signal by contacting with a fluid sample. The lead-out area BB is used to form a lead-out structure to lead out the electrical signal formed by the detection area AA. The detection area AA can be of any suitable shape (cross-sectional shape). The lead-out area BB is located outside the detection area AA and surrounds or partially surrounds the detection area AA. In this embodiment, the detection area AA may be rectangular, and the lead-out area BB may be rectangular ring-shaped.

[0054] Next, please refer to Figure 2b , and perform step S02 to sequentially form an isolation layer 11 and a conductive material layer 21. The isolation layer 11 covers the substrate 10, and the conductive material layer 21 covers the isolation layer 11.

[0055] The isolation layer 11 is used to isolate the substrate 10 from the conductive material layer 21, and its material can be any suitable insulating material, such as silicon oxide, etc. The conductive material layer 21 is used to form a current path, and its material can be any suitable conductive material. However, it can be understood that the material of the conductive material layer 21 needs to be matched with the subsequent detection film layer so that the detection film layer can adhere to its surface and generate corresponding electrical changes (electrical signals). In this embodiment, the material of the isolation layer 11 can include silicon oxide, and the material of the conductive material layer 21 can include polysilicon or doped polysilicon.

[0056] Next, please refer to Figure 2c and Figure 2d , and perform step S03 to perform a patterning process on the conductive material layer 21 to form a conductive structure layer. The conductive structure layer includes a plurality of intersecting and communicating conductive channels 24 provided on the detection area AA, and two lead electrodes connected to the conductive channels 24 provided on the lead-out area BB. A groove 25 is formed between adjacent conductive channels 24.

[0057] The conductive channels 24 can be in the shape of fins (rectangular or trapezoidal) protruding from the surface of the isolation layer 11. A plurality of conductive channels 24 intersect and communicate on the isolation layer 11 of the detection area AA, and a groove 25 surrounded by the conductive channels 24 is formed between adjacent conductive channels 24. The side walls of the conductive channels 24 are exposed by using the groove 25 to significantly increase the area on the outer wall of the conductive channels 24 for attaching the detection film layer, that is, to increase the contact area between the flowing sample and the detection film layer, thereby improving the detection accuracy. The size of the groove 25 is the spacing distance between the conductive channels 24 in different directions, and its size can be of the same order of magnitude as the conductive groove 25. In this embodiment, the width (line width) of the conductive channels 24 can be 50 nanometers to 500 nanometers, and the spacing (line pitch) between adjacent conductive channels 24 can be 50 nanometers to 500 nanometers. Of course, this embodiment does not limit the line width or line pitch of the conductive channels 24.

[0058] The lead electrodes are provided on the two opposite sides (ends) of the detection area AA (conductive channels 24), and a plurality of conductive channels 24 can be led out, for example, from two diagonal regions of the detection area AA. It should be noted that the diagonal regions here can also be close to the diagonal or close to the diagonal region, not the absolute diagonal, and even parallel and opposite are also feasible. In addition, the lead electrodes and the conductive channels 24 can also be integrated in some regions, that is, part of the lead electrodes extend into the detection area AA, or part of the conductive channels 24 extend into the lead-out area BB is also feasible. Therefore, in addition to being surrounded by adjacent conductive channels 24, the above groove 25 can also be surrounded by the conductive channels 24 and the lead-out parts of the lead electrodes. Of course, the size of the lead electrodes can be larger than that of the conductive channels 24 to reduce the line resistance.

[0059] Specifically, a mask material layer composed of several different materials stacked on top of each other may be first formed on the conductive material layer 21, such as a silicon nitride layer, an advanced pattern mask layer, a bottom anti-reflection layer, and a photoresist layer stacked in sequence from bottom to top; then a photolithography process is performed on the photoresist layer to form a patterned photoresist layer, and the patterned photoresist layer is used to perform a patterning process to form the above-mentioned several conductive channels 24 and lead-out electrodes. As Figure 2c and Figure 2d shown, Figure 2c is a cross-sectional schematic diagram, Figure 2d is a top-view schematic diagram. The several conductive channels 24 linearly extend, intersect, and communicate with each other in the transverse and longitudinal directions to form a grid shape. The grooves 25 are the hollow parts of the grid and are rectangular in shape. The bottom of the grooves 25 exposes the surface of the isolation layer 11. The widths of the two lead-out electrodes may both be greater than the width of the conductive channel 24. The two lead-out electrodes are, for example, a first electrode 22 and a second electrode 23. The first electrode 22 (on the left side in the figure) may be in an L shape, and the second electrode 23 (on the right side in the figure) may be in a T shape. Both the first electrode 22 and the second electrode 23 include lead-out parts (a first lead-out part 22a and a second lead-out part 23a) connected to the conductive channel 24 and electrode parts (a first electrode part 22b and a second electrode part 23b) extending from the lead-out parts. Among them, the two electrode parts are provided at both ends of the detection area AA. The lead-out part (the first lead-out part 22a) of the first electrode 22 may be located at the edge of the detection area AA (partially located in the detection area AA), and the lead-out part (the second lead-out part 23a) of the second electrode 23 may completely extend into the detection area AA and communicate with the conductive channel 24 in the transverse direction (D2 direction) and lead out.

[0060] In addition, in a preferred example, after forming the conductive channels 24 and the lead-out electrodes, a patterned mask may be formed to cover the conductive channels 24, exposing the lead-out electrodes, and then ion implantation (such as P+ ion implantation) is performed on the lead-out electrodes, and a metal silicide (not shown) is formed on the polysilicon surface at the lead-out electrode contact holes to reduce the contact resistance, and it can also be used as an etch stop layer for subsequent formation of the contact holes 31. It is not difficult to understand that ion implantation is performed on the electrode parts of the first electrode 22 and the second electrode 23 and a metal silicide is formed at the contact holes to prevent the metal silicide from entering the detection area AA and thus affecting the adhesion effect of the detection film layer on its surface.

[0061] Preferably, after forming the conductive structure layer, ion implantation is also performed on the lead-out electrodes, and a metal silicide (not shown) is formed on the surface of part of the lead-out electrodes. Among them, the area where the metal silicide is formed on the lead-out electrodes may correspond to the subsequent electrode holes.

[0062] Next, step S04 is executed to form an insulating layer covering the isolation layer 11 and the conductive structure layer, form at least two contact electrodes 32 in the insulating layer on the lead-out region BB to connect with the lead-out electrodes, and remove the insulating layer in the detection region AA to form a receiving cavity 34 to expose the conductive channel 24 and the trench 25.

[0063] Specifically, please refer to Figure 2e , form an insulating material layer 27a to cover the isolation layer 11 and the conductive structure layer and fill it above the conductive structure layer. The height of the insulating material layer 27a is higher than the height of the conductive channel 24, and its height can be the depth of the subsequent receiving cavity 34. Preferably, before forming the insulating material layer 27a, an insulating barrier layer 26 can also be formed to conformally cover the outer wall of the conductive structure layer and the surface of the isolation layer 11 to improve the electrical isolation effect on the conductive structure layer and serve as a protective layer when the insulating material layer 27a is opened later. The material of the insulating barrier layer 26 can include silicon nitride or silicon oxynitride, etc., and the material of the insulating material layer 27a can include silicon oxide.

[0064] Please refer to Figure 2f and Figure 2g , perform a patterning process on the insulating material layer 27a to form contact holes 31 exposing the lead-out electrodes in the insulating material layer 27a on the lead-out region BB. The step of forming the contact holes 31 can include, first, forming a patterned mask on the insulating material layer 27a, and the patterned mask is provided with at least one opening on the electrode parts in the two lead-out regions BB on both sides, and use the above openings to etch the insulating material layer 27a and the insulating barrier layer 26 to expose the metal silicide on the electrode parts. Among them, Figure 2f is a cross-sectional schematic diagram, Figure 2g is a top view schematic diagram. As shown in Figure 2g , in this embodiment, two contact holes 31 are provided in the insulating material layer 27a on each electrode part. The two contact holes 31 on each electrode part respectively expose both ends of the electrode part from the detection region AA (conductive channel 24) (for example, the far end and the near end of the circuit). A total of four contact holes 31 are provided in the insulating material layer 27a on the two electrode parts. The two contact holes 31 (the second contact hole 31b and the third contact hole 31c) provided at the near end of the circuit are used to form two contact electrodes for providing a constant current, and the two contact holes 31 (the first contact hole 31a and the fourth contact hole 31d) provided at the far end of the circuit are used to form two contact electrodes for detecting the voltage between the lead-out electrodes.

[0065] Please refer to Figure 2h , sequentially form a metal barrier layer ( Figure 2h not shown in the figure) and a metal material layer 321 to cover the inner wall of the contact holes 31 and the surface of the insulating material layer 27a. Among them, a metal adhesion layer can also be provided between the metal barrier layer and the metal silicide at the bottom of the contact holes 31 ( Figure 2h(not shown in the figure) to improve the adhesion effect of the metal barrier layer and reduce the contact resistance. Among them, the materials of the metal barrier layer and the metal adhesion layer can be matched with the metal material layer 321. Taking the material of the metal material layer 321 including aluminum as an example, the material of the metal barrier layer can include titanium nitride, and the material of the metal adhesion layer can include titanium.

[0066] Please refer to the metal material layer 321 Figure 2i and Figure 2j , remove the metal barrier layer and the metal material layer 321 outside the contact hole 31, and use the metal material layer 321 in the contact hole 31 as the contact electrode 32 (which may also include the metal barrier layer). In one example, a patterned mask is formed to cover the contact hole 31 and expose the area outside the contact hole 31, and then an etching process is performed to remove the metal barrier layer and the metal material layer 321 outside the contact hole 31. In other examples of this embodiment, a polishing process can also be performed to remove the metal barrier layer and the metal material layer 321 outside the contact hole 31. In the example illustrated in this embodiment, the metal material layer 321 covers the inner wall of the contact hole 31 but does not fill the contact hole 31, so that the formed contact electrode 32 covers the inner wall of the contact hole 31 and is concave. In other examples of this embodiment, the metal material layer 321 can also fill the contact hole 31 above the insulating material layer 27a, that is, fill the contact hole 31, so that the formed contact electrode 32 fills the contact hole 31 and is in a columnar shape inside.

[0067] Please refer to Figure 2k , form a patterned mask 33 to cover the insulating material layer 27a and the contact electrode 32 in the lead-out area BB, and the opening of the patterned mask 33 exposes the insulating material layer 27a in the detection area AA.

[0068] Please refer to Figure 2l and Figure 2m , using the patterned mask 33, perform an etching process to sequentially remove the insulating material layer 27a and the insulating barrier layer 26 in the detection area AA to form a receiving cavity 34, expose the conductive channel 24 and the trench 25, and use the remaining insulating material layer 27a as the insulating layer 27. Among them, Figure 2l is a cross-sectional schematic diagram, Figure 2m is a top view schematic diagram. In this embodiment, the receiving cavity 34 can be rectangular, the bottom of the receiving cavity 34 exposes the isolation layer 11, the receiving cavity 34 also exposes a partial lead-out portion of the first electrode 22 extending into the detection area AA, and exposes the lead-out portion of the second electrode 23 extending into the detection area AA.

[0069] In addition, after forming the above-mentioned conductive structure layer, insulating layer 23, contact electrode 32, and accommodation cavity 34, a detection film layer matching the fluid sample to be detected is formed on the outer wall of the conductive structure layer (including a partial lead-out portion of the conductive channel 24 and the lead-out electrode) exposed in the accommodation cavity 34. The conductive structure layer with the detection film layer attached is used as the detection structure. By contacting with the fluid sample, the change in the electrical properties (such as resistance) of the detection structure is led out to achieve high-precision quantitative detection of the concentration or content of the fluid sample. Compared with the related art that uses optical methods to detect biological signals, this embodiment combines chip technology with biological detection, and the detection chip prepared by the CMOS process has highly uniform specifications, which can effectively reduce the adverse effects of process deviations in the related art on the final detection result, and can also reduce the corresponding detection cost. Moreover, when using the above-mentioned detection chip to detect a fluid sample (biological sample), high automation can be achieved in both the sample loading and detection links, reducing the requirements for environmental conditions, and optimizing the sample preparation link to reduce manual operations. This not only makes the entire detection process (including loading the sample and detecting the sample) more efficient, but also avoids errors introduced by manual participation.

[0070] Embodiment 2

[0071] Embodiment 2 provides a detection chip.

[0072] Figure 2l is a cross-sectional schematic diagram (partial structure) of the detection chip provided by Embodiment 2; Figure 2m is a top-view schematic diagram (partial structure) of the detection chip provided by Embodiment 2.

[0073] As Figure 2l and Figure 2m shown, the detection chip provided by this embodiment is used to detect a fluid sample, and can be prepared, for example, by the preparation method provided in Embodiment 1. It includes a substrate 10, an isolation layer 11, a conductive structure layer, an insulating layer, a contact electrode 32, and an accommodation cavity 34. The substrate 10 has a detection area AA and a lead-out area BB surrounding the detection area AA. The isolation layer 11 covers the surface of the substrate 10. The conductive structure layer, located on the isolation layer 11, includes a plurality of intersecting and communicating conductive channels 24 provided on the detection area AA, and two lead-out electrodes connected to the conductive channels 24 provided on the lead-out area BB. A groove 25 is formed between adjacent conductive channels 24. The insulating layer covers the isolation layer 11 and the conductive structure layer, and forms an accommodation cavity 34 on the detection area AA to expose the conductive channels 24 and the grooves 25. The accommodation cavity 34 is used to load the fluid sample. At least two contact electrodes 32 are provided in the insulating layer on the lead-out area BB and are connected to the lead-out electrodes to electrically lead out the two lead-out electrodes.

[0074] Among them, the conductive channel 24 may be in the shape of a fin (rectangular or trapezoidal) protruding from the surface of the isolation layer 11, and a plurality of conductive channels 24 are interlaced and connected on the isolation layer 11 of the detection area AA, and a groove 25 surrounded by the conductive channels 24 is formed between adjacent conductive channels 24, and the side wall of the conductive channel 24 is exposed by the groove 25, so as to significantly increase the area on the outer wall of the conductive channel 24 for attaching the detection film layer, that is, to increase the contact area between the flowing sample and the detection film layer, thereby improving the detection accuracy. The size of the groove 25 is the spacing distance between the conductive channels 24 in different directions, and its size may be of the same order of magnitude as the conductive channel 25. In this embodiment, the width (line width) of the conductive channel 24 may be 50 nanometers to 500 nanometers, and the spacing (line pitch) between adjacent conductive channels 24 may be 50 nanometers to 500 nanometers. Of course, this embodiment is not limited by the line width or line pitch of the conductive channel 24. In addition, part of the trench 25 may also be surrounded by the conductive channel 24 and the adjacent insulating layer.

[0075] The lead-out electrodes are arranged on opposite sides (two ends) of the detection area AA (conductive channels 24), and several conductive channels 24 can be led out from the two diagonal areas of the detection area AA, for example, so that the current flows as evenly as possible through the entire detection area AA. It should be noted that the diagonal area here is close to the diagonal line or close to the diagonal area, which is not an absolute diagonal line. In addition, the lead-out electrode and the conductive channel 24 can also be regarded as one in some areas, that is, part of the lead-out electrode extends into the detection area AA for attaching the detection film layer, or part of the conductive channel 24 extends into the lead-out area BB. Therefore, the above-mentioned groove 25 is surrounded by adjacent conductive channels 24 (including insulating layers) and can also be surrounded by the conductive channel 24 and the lead-out portion of the lead-out electrode.

[0076] Specifically, a plurality of conductive channels 24 linearly extend, intersect, and communicate with each other along the transverse direction (e.g., the D2 direction) and the longitudinal direction (e.g., the D1 direction) to form a grid shape. The grooves 25 are the hollow parts of the grid and are rectangular in shape. The bottom of the grooves 25 exposes the surface of the isolation layer 11. The widths of the two lead electrodes can both be greater than the width of the conductive channel 24. The two lead electrodes are, for example, the first electrode 22 and the second electrode 23. The first electrode 22 (the left side in the figure) can be in an L shape, and the second electrode 23 (the right side in the figure) can be in a T shape. Both the first electrode 22 and the second electrode 23 include lead portions (the first lead portion 22a and the second lead portion 23a) connected to the conductive channel 24 and electrode portions (the first electrode 22 portion and the second electrode 23 portion) extending from the lead portions. Among them, the two electrode portions are arranged at both ends of the detection area AA. The lead portion of the first electrode 22 can be located at the edge of the detection area AA (partially located in the detection area AA), longitudinally communicate with the conductive channel 24 and lead out. The lead portion of the second electrode 23 can completely extend into the detection area AA, laterally communicate with the conductive channel 24 and lead out. In addition, in a preferred example, metal silicide is formed on part of the surfaces (or outer walls) of the electrode portions of the two lead electrodes to reduce the contact resistance and can also be used as an etching stop layer for subsequently forming the contact holes 31.

[0077] It should be noted that the above detection chip also forms a detection film layer matching the fluid sample to be detected on the outer wall of the conductive structure layer (including part of the lead portions of the conductive channels 24 and the lead electrodes) exposed in the accommodation cavity 34, and uses the conductive structure layer with the detection film layer attached as the detection structure. By contacting with the fluid sample, the change in the electrical properties (such as resistance) of the detection structure is led out to achieve high-precision quantitative detection of the concentration or content of the fluid sample. In this embodiment, the detection of the fluid sample can be realized by detecting the change in the resistance of the detection structure, and the Kelvin four-wire resistance measurement method is preferably used to improve the detection accuracy. Specifically, two contact electrodes 32 are respectively provided in the insulating material layer 27a on each electrode portion. The two contact electrodes 32 on each electrode portion are respectively arranged at the circuit far end and the circuit near end of the detection area AA (conductive channel 24). That is, a total of four contact electrodes 32 are provided in the insulating material layer 27a on the two electrode portions. The two contact electrodes 32 (the second contact electrode 32b and the third contact electrode 32c) arranged at the circuit near end are used to measure the voltage, and the two contact electrodes 32 (the first contact electrode 32a and the fourth contact electrode 32d) arranged at the circuit far end measure the current. In Figure 2m the illustrated example, the contact electrode 32 covers the inner wall of the contact hole 31 and is concave, that is, the contact electrode 32 does not fill the contact hole 31. In other examples of this embodiment, the formed contact electrode 32 fills the contact hole 31 and is in an inner columnar shape, that is, the contact electrode 32 fills the contact hole 31.

[0078] Embodiment Three

[0079] Embodiment 3 provides a detection chip.

[0080] Figures 3a - 3d It is a top view schematic diagram of the detection chip provided by Embodiment 3.

[0081] As shown above, the detection chip provided by Embodiment 3 is used to detect a fluid sample, and includes a substrate 10, an isolation layer 11, a conductive structure layer, an insulating layer, contact electrodes 32 and a receiving cavity 34. The substrate 10 has a detection area AA and a lead-out area BB surrounding the detection area AA. The isolation layer 11 covers the surface of the substrate 10. The conductive structure layer is located on the isolation layer 11 and includes a plurality of intersecting and communicating conductive channels 24 provided on the detection area AA, and two lead-out electrodes connected to the conductive channels 24 provided on the lead-out area BB. A groove 25 is formed between adjacent conductive channels 24. The insulating layer covers the isolation layer 11 and the conductive structure layer, and forms a receiving cavity 34 on the detection area AA to expose the conductive channels 24 and the grooves 25. The receiving cavity 34 is used to load the fluid sample. At least two contact electrodes 32 are provided in the insulating layer on the lead-out area BB and electrically lead out the two lead-out electrodes. The detection chip provided by Embodiment 3 is similar to the detection chip provided by Embodiment 2 in basic structure and basic principle, and the difference lies only in the structure of the conductive structure layer.

[0082] Specifically, please refer to Figure 3a , the detection area AA can be rectangular, and a plurality of conductive channels 24 arranged along the transverse direction (D2 direction) and the longitudinal direction (D1 direction) and intersecting and communicating are provided in the detection area AA. The lead-out electrodes are all located in the lead-out area BB, and the conductive channels 24 extend out of the detection area AA to be connected to the lead-out electrodes.

[0083] In the example as Figure 3b shown, only one contact electrode 32 can be provided in the insulating layer on each lead-out electrode, that is, a total of two contact electrodes 32 (the first contact electrode 32a and the second contact electrode 32b) are provided on the two lead-out electrodes. The electrical parameter change (such as resistance change) of the conductive channels 24 in the detection area AA is measured by the two-wire method to detect the fluid sample.

[0084] In the example as Figure 3c and Figure 3dSchematic diagram of the conductive structure layer shown, the detection area AA and the lead-out area BB include a plurality of structures similar to those in the second embodiment. Specifically, the first electrode includes a first electrode portion 22b and a plurality of first lead-out portions 22a extending into the detection area AA, the second electrode includes a second electrode portion 23b and a plurality of second lead-out portions 23a extending into the detection area AA, the first electrode and the second electrode form a finger-like shape, and a plurality of conductive channels communicate with the fingers in a direction perpendicular to the fingers (the first lead-out portions 22a and the second lead-out portions 23a) to form a groove 25 by using the conductive channels 24, the first lead-out portions 22a and the second lead-out portions 23a. Among them, in Figure 3c In the example of Figure 3d , a conductive channel 24 is provided between adjacent fingers (the first lead-out portions 22a and the second lead-out portions 23a) for connection; in Figure 3c In the example shown in the conductive structure layer of Figure 3d similarly

[0085] Taking the example of providing two contact electrodes on each lead-out electrode, the four contact electrodes can be respectively arranged at the opposite ends of the first electrode portion 22b and the second electrode portion 23b, and two contact electrodes (such as the first contact electrode 32a and the fourth contact electrode 32d) in the diagonal positions are used to apply a constant current to the detection area, and the remaining two (in the other diagonal position) contact electrodes (such as the second contact electrode 32b and the third contact electrode 32c) are used to measure the voltage across the detection area. In addition, it is also feasible that the first contact electrode 32a and the fourth contact electrode 32d are used to measure the voltage across the detection area, and the second contact electrode 32b and the third contact electrode 32c apply a constant current to the detection area.

[0086] In summary, for the detection chip provided by the present invention, a conductive structure layer, an insulating layer, and a contact electrode are provided on the isolation layer of the substrate. The conductive structure layer includes a plurality of intersecting and communicating conductive channels provided on the detection area, and two lead electrodes provided on the lead-out area and connected to the conductive channels. A groove is formed between adjacent conductive channels. The insulating layer covers the isolation layer and the conductive structure layer, and a receiving cavity is formed on the detection area to expose the conductive channels and the grooves. The contact electrode is provided in the insulating layer on the lead-out area and is connected to the lead electrode. Compared with the optical method for detecting biological signals in the related art, in this embodiment, chip technology is combined with biological detection, and the detection chip prepared by the CMOS process has highly uniform specifications, which can effectively reduce the adverse effects of various process deviations in the related art on the final detection result, and can also reduce the corresponding detection cost. Moreover, when the above detection chip is used to detect a fluid sample (biological sample), high automation can be achieved in both the sample loading and detection links, reducing the requirements for environmental conditions and optimizing the sample preparation link to reduce manual operations. This not only makes the entire detection process (including loading and detecting the sample) more efficient, but also avoids errors introduced by manual participation. In addition, in the above detection chip, the conductive channels intersect and communicate in the detection area, and grooves are formed between adjacent conductive channels. The side walls of the conductive channels are exposed by using the grooves, so as to significantly increase the contact area between the outer wall of the conductive channel and the flowing sample, thereby improving the detection accuracy.

[0087] The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention in any way. Any changes and modifications made by those of ordinary skill in the art of the present invention according to the above disclosure are within the protection scope of the claims.

Claims

1. A detection chip for detecting a fluid sample, characterized in that, Comprising: A substrate having a detection region and a lead-out region surrounding the detection region; An isolation layer covering the surface of the substrate; A conductive structure layer located on the isolation layer, including a plurality of intersecting and connected conductive channels provided on the detection region, and two lead-out electrodes provided on the lead-out region and connected to the conductive channels, with grooves formed between adjacent conductive channels; An insulating layer covering the isolation layer and the conductive structure layer, and forming a receiving cavity on the detection region to expose the conductive channels and the grooves, the receiving cavity being used to load the fluid sample; At least two contact electrodes provided in the insulating layer on the lead-out region and electrically leading out the two lead-out electrodes.

2. The detection chip according to claim 1, characterized in that, The conductive channels are fin-shaped, a plurality of the conductive channels are in a criss-cross grid shape, and the grooves are rectangular.

3. The detection chip according to claim 2, characterized in that, The detection region is rectangular, and the two lead-out electrodes are provided on opposite sides of the detection region and lead out the conductive channels from both sides of the detection region.

4. The detection chip according to claim 3, characterized in that, Part of the lead-out electrodes also extend into the detection region.

5. The detection chip according to claim 1, characterized in that, Contact holes exposing the lead-out electrodes are formed in the insulating layer on the lead-out region, and the contact electrodes cover the inner walls of the contact holes to be concave, or the contact electrodes fill the contact holes to the surface of the insulating layer to be columnar.

6. The detection chip according to claim 1, characterized in that, Two contact electrodes are provided on each lead-out electrode, and the two contact electrodes provided on the two lead-out electrodes respectively are used to apply a constant current to the detection region, and the remaining two contact electrodes are used to measure the voltage across the detection region.

7. The detection chip according to claim 1, characterized in that, A detection film layer is further provided on the outer wall of the conductive channels exposed in the receiving cavity, and the detection film layer is used for detection in an opposite manner to the fluid sample.

8. A method for preparing a detection chip, characterized in that, Comprising: Providing a substrate having a detection region and a lead-out region surrounding the detection region; Forming an isolation layer and a conductive material layer, the isolation layer covering the substrate, and the conductive material layer covering the isolation layer; Performing a patterning process on the conductive material layer to form a conductive structure layer, the conductive structure layer including a plurality of intersecting and connected conductive channels provided on the detection region, and two lead-out electrodes provided on the lead-out region and connected to the conductive channels, with grooves formed between adjacent conductive channels; Forming an insulating layer to cover the isolation layer and the conductive structure layer, forming at least two contact electrodes in the insulating layer on the lead-out region to electrically lead out the two lead-out electrodes, and removing the insulating layer in the detection region to form a receiving cavity to expose the conductive channels and the grooves.

9. The method for preparing a detection chip according to claim 8, characterized in that, The material of the conductive material layer includes polysilicon, and the steps of forming the contact electrodes include: After forming the conductive structure layer, performing ion implantation on the lead-out electrodes, and forming metal silicide on the surface of part of the lead-out electrodes, and then forming an insulating barrier layer to cover the outer wall of the conductive structure layer and the surface of the isolation layer. Forming an insulating material layer to cover the isolation layer and the conductive structure layer and filling it above the conductive structure layer; Performing a patterning process on the insulating material layer to form contact holes exposing the metal silicide on the lead-out electrodes in the insulating material layer on the lead-out region; A metal barrier layer and a metal material layer are sequentially formed to cover the inner wall of the contact hole and the surface of the insulating material layer; The metal barrier layer and the metal material layer outside the contact hole are removed, and the metal barrier layer and the metal material layer in the contact hole are used as the contact electrode.

10. The method for preparing a detection chip according to claim 9, characterized in that, The step of forming the accommodation cavity includes: A patterned mask is formed to cover the insulating material layer and the contact electrode in the lead-out area, and the opening of the patterned mask exposes the insulating material layer in the detection area; Using the patterned mask, an etching process is performed to sequentially remove the insulating material layer and the insulating barrier layer in the detection area to form the accommodation cavity, exposing the conductive channel and the trench, and using the remaining insulating material layer as the insulating layer.

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