Pixel structure of detector and manufacturing method thereof
By designing an insulating layer opening structure in which the electrodes are not covered by the insulating layer in the detector cell structure, the white point problem in the detector is solved, avoiding the effective resistance of the resistor layer and improving image quality.
Patent Information
- Application Number
- CN202411183213.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-26
- Publication Date
- 2024-12-13
AI Technical Summary
In the non-cooled infrared focal plane detector array, the problem of black or white dots caused by excessive difference between the cell resistance and the surrounding cell resistance, especially the white dots are caused by local short circuits, resulting in unevenness in the scene image.
In the cell structure of the detector, the surface of the electrode is not covered by the insulating layer to avoid the formation of the insulating layer steps, thereby preventing the effective resistance length of the resistive layer from being shortened. The structure of the first insulating layer, the second insulating layer and the resistive layer is adopted. The electrode part is located in the insulating layer opening, and the design of the insulating layer opening avoids step damage of the insulating layer.
It effectively suppresses the white dot phenomenon in the scene image of the detector, avoids the shortening of the effective resistance length of the resistor layer, and improves the stability and image quality of the cell.
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Figure CN119133195A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of semiconductor integrated circuit manufacturing, and in particular to a pixel structure of a detector and a manufacturing method thereof. Background Art
[0002] Common sizes of uncooled infrared focal plane detector arrays are 640×512, 1024×768, 1920×1080, etc. Each pixel on the array represents a pixel, and all pixels are spliced together to form the final scene image. If the resistance value of some pixels on the array differs from the resistance of the surrounding pixels to a degree that cannot be corrected by the system, a black or white dot will appear on the scene image. Black dots are generally caused by the resistance of the pixel being larger than the resistance of the surrounding pixels; while white dots are just the opposite. The main reason for the generation of white dots is that the pixel has a local short circuit problem, resulting in a small resistance of the pixel.
[0003] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because they are described in the background technology section of the present application. Summary of the invention
[0004] White spot problems often occur in the lower electrode process, that is, the electrode metal is under the heat-sensitive material. In the lower electrode process, the metal electrode is first made, and then the heat-sensitive material is deposited and patterned on the metal electrode.
[0005] The inventors found that, since a long pre-treatment is required before the deposition of the thermosensitive material to remove the oxide layer on the metal surface, the insulating layer between the metal electrode and the thermosensitive material (for example, the insulating layer is generally silicon nitride or silicon dioxide, etc.) will be excessively consumed. Excessive consumption of the insulating layer can easily cause local breakdown, resulting in a short circuit between the electrode metal and the thermosensitive material where it should be insulated, leading to the white spot problem.
[0006] Figure 1 It is a schematic diagram of the pixel structure of the detector in the prior art. Figure 1 In the figure, 10 represents high-temperature silicon nitride, 20 represents low-temperature silicon nitride, 30 represents metal titanium (ie, a metal electrode), and 40 represents vanadium oxide (ie, a resistor formed by a heat-sensitive material).
[0007] like Figure 1As shown, in the pixel structure of the existing detector, the surface of the metal titanium 30 is covered with low-temperature silicon nitride 20, and a contact hole is opened in the low-temperature silicon nitride 20. The center distance between the two contact holes is smaller than the length of the vanadium oxide 40, and the area of the contact hole opening is smaller than the area of the metal electrode 30. The vanadium oxide 40 contacts the electrode metal 30 only in the area where the contact hole is opened. There is a layer of low-temperature silicon nitride 20 between the vanadium oxide 40 and the high-temperature silicon nitride 10. The length of the contact hole is d1, the length from the edge of the contact hole to the step is d2, and the distance between the outer edges of the two contact holes is d.
[0008] exist Figure 1 In the structure shown, a relatively long pre-treatment (for example, treating the surface of the metal titanium 30) is required before the deposition of the vanadium oxide 40. Figure 1 The low-temperature silicon nitride 20 of the electrode metal step shown in the figure will be over-consumed, and the metal titanium 30 is easily exposed at the step. In this way, after the vanadium oxide 40 is deposited, the vanadium oxide 40 is short-circuited with the metal titanium 30, and the effective resistance length of the resistor formed by the vanadium oxide 40 is shortened by d2 on one side, resulting in a small resistance value of the vanadium oxide 40 of the pixel, causing small white spots.
[0009] In order to solve the above-mentioned problems or at least similar problems, an embodiment of the present application provides a pixel structure of a detector and a manufacturing method thereof. In the pixel structure, in the area below the resistance layer, the surface of the electrode is not covered by the insulating layer, and no steps of the insulating layer are formed. Therefore, there is no risk of leakage caused by damage to the steps of the insulating layer in the area below the resistance layer, and the shortening of the effective resistance length of the resistance layer is avoided. Therefore, the white spot phenomenon in the scene image generated by the detector can be suppressed.
[0010] According to one aspect of an embodiment of the present application, a pixel structure of a detector is provided, the pixel structure comprising:
[0011] A first insulating layer 1;
[0012] A second insulating layer 2 is formed on the surface of the first insulating layer 1, wherein the second insulating layer 2 has an opening;
[0013] Two electrodes 3 are formed on the surface of the first insulating layer 1, each of the electrodes 3 is at least partially located in the opening, and in the opening, the surface of each of the electrodes 3 is not covered by the second insulating layer 2; and
[0014] A resistance layer 4 is formed on the surface of the first insulating layer 1 , and the resistance layer 4 is in contact with each of the electrodes 3 in the opening.
[0015] In at least one embodiment, within the opening, between the ends of the electrodes 3 that are close to each other, the resistance layer 4 contacts the surface of the first insulating layer 1 .
[0016] In at least one embodiment, at least one of the electrodes 3 extends outside the opening and is covered by the second insulating layer 2 .
[0017] In at least one embodiment, at least one of the electrodes 3 is entirely located within the opening.
[0018] In at least one embodiment, the first insulating layer 1 and the second insulating layer 2 are both silicon nitride, and the formation temperature of the first insulating layer 1 is higher than the formation temperature of the second insulating layer 2; and / or
[0019] The material of the electrode comprises titanium; and / or
[0020] The material of the resistance layer 4 includes vanadium oxide.
[0021] According to another aspect of an embodiment of the present application, a method for manufacturing a pixel structure of a detector is provided, the manufacturing method comprising:
[0022] forming a first insulating layer 1;
[0023] Two electrodes 3 are formed on the surface of the first insulating layer 1;
[0024] forming a second insulating layer 2 on the surface of the first insulating layer 1, and forming an opening in the second insulating layer 2, wherein each of the electrodes 3 is at least partially located in the opening, and within the opening, the surface of each of the electrodes 3 is not covered by the second insulating layer 2; and
[0025] A resistance layer 4 is formed on the surface of the first insulating layer 1 , and the resistance layer 4 is in contact with each of the electrodes 3 in the openings.
[0026] The beneficial effect of the present application is that in the pixel structure, in the area below the resistance layer, the surface of the electrode is not covered by the insulating layer, and no steps of the insulating layer are formed. Therefore, there is no risk of leakage caused by damage to the steps of the insulating layer in the area below the resistance layer, and the shortening of the effective resistance length of the resistance layer is avoided. Therefore, the white spot phenomenon in the scene image generated by the detector can be suppressed.
[0027] With reference to the following description and accompanying drawings, the specific embodiments of the present application are disclosed in detail, indicating the way in which the principles of the present application can be adopted. It should be understood that the embodiments of the present application are not limited in scope. Within the scope of the spirit and clauses of the appended claims, the embodiments of the present application include many changes, modifications and equivalents.
[0028] Features described and / or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.
[0029] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps or components. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The included drawings are used to provide a further understanding of the embodiments of the present application, which constitute a part of the specification, are used to illustrate the implementation methods of the present application, and together with the text description, explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:
[0031] Figure 1 It is a schematic diagram of the pixel structure of a detector in the prior art;
[0032] Figure 2 is a schematic diagram of a pixel structure of a detector according to an embodiment of the present application;
[0033] Figure 3 is another schematic diagram of the pixel structure of the detector according to an embodiment of the present application;
[0034] Figure 4 It is a schematic diagram of the manufacturing method of the pixel structure. DETAILED DESCRIPTION
[0035] With reference to the accompanying drawings, the above and other features of the present application will become apparent through the following description. In the description and the accompanying drawings, specific embodiments of the present application are specifically disclosed, which show some embodiments in which the principles of the present application can be adopted. It should be understood that the present application is not limited to the described embodiments. On the contrary, the present application includes all modifications, variations and equivalents falling within the scope of the attached claims.
[0036] In the description of the various embodiments of the present application, for the convenience of description, the direction parallel to the surface of the substrate is called "lateral", the direction perpendicular to the surface of the substrate is called "longitudinal", and the dimension in the "longitudinal" direction can be called "height" or "thickness"; in the "longitudinal" direction, the direction from the first insulating layer 1 to the second insulating layer 2 is called the "up" direction, and the opposite direction to the "up" direction is the "down" direction.
[0037] It should be noted that the above-mentioned “up” direction and “down” direction are only for the convenience of explanation and do not limit the orientation or posture of the pixel structure of the detector of the present application during manufacturing or use.
[0038] An embodiment of the present application provides a pixel structure of a detector.
[0039] Figure 2 FIG. 1 is a schematic diagram of the pixel structure of the detector of the embodiment of the present application. Figure 2 As shown, the pixel structure includes: a first insulating layer 1, a second insulating layer 2, an electrode 3 and a resistor layer 4.
[0040] The first insulating layer 1 is, for example, formed on a surface of a substrate 100. The substrate 100 is, for example, a silicon substrate, a glass substrate, or the like.
[0041] The second insulating layer 2 is formed on the surface of the first insulating layer 1 , wherein the second insulating layer 2 has an opening 21 .
[0042] At least two electrodes 3 are formed on the surface of the first insulating layer 1 , and each electrode 3 is at least partially located in the opening 21 . Furthermore, in the opening 21 , the surface of each electrode 3 is not covered by the second insulating layer 2 .
[0043] The resistance layer 4 is formed on the surface of the first insulating layer 1, and the resistance layer 4 is in contact with each electrode 3 in the opening. Thus, the resistance layer 4 between two electrodes 3 forms a resistor, and its resistance value is related to the minimum distance between the two electrodes 3 (that is, the effective resistance length). Figure 2 In the figure, the size of the opening 21 is d, and the length of contact between each electrode 3 and the resistor layer 4 inside the opening 21 is d1. The resistance value of the resistor is related to (d-2*d1).
[0044] According to an embodiment of the present application, in the pixel structure of the detector, in the area below the resistance layer 4, within the opening 21, the surface of the electrode 3 is not covered by the second insulating layer 2, and no steps of the second insulating layer 2 are formed. Therefore, there is no risk of leakage due to damage of the steps of the second insulating layer 2 in the area below the resistance layer 4, and the shortening of the effective resistance length of the resistance layer 4 is avoided. Therefore, the white spot phenomenon in the scene image generated by the detector can be suppressed.
[0045] In the opening 21, between the ends of the electrodes 3 that are close to each other (for example, Figure 2 In the region 211 shown, the resistance layer 4 contacts the surface of the first insulating layer 1 .
[0046] like Figure 2 As shown, in some embodiments, at least one electrode 3 extends outside the opening 21 and is covered by the second insulating layer 2 (eg, Figure 2Thus, in the process of etching the second insulating layer 2 to form the opening 21, the edge of the opening 21 is located on the surface of the electrode 3, and the electrode 3 can stop the etching automatically.
[0047] Figure 3 It is another schematic diagram of the pixel structure of the detector according to an embodiment of the present application. Figure 3 and Figure 2 The same content will not be repeated. Figure 3 and Figure 2 The difference is: Figure 3 In the embodiment, at least one electrode 3 is entirely located in the opening, that is, at least one electrode 3 is not covered by the second insulating layer 2. Figure 3 In the embodiment, both electrodes 3 are not covered by the second insulating layer 2. Thus, the resistor layer 4 is in contact with the entire electrode 3, which can avoid aligning the electrode 3 with the opening 21, thereby reducing the requirement for alignment accuracy.
[0048] In the embodiment of the present application, the first insulating layer 1 and the second insulating layer 2 are both silicon nitride, wherein the formation temperature of the first insulating layer 1 is higher than the formation temperature of the second insulating layer 2. For example, the first insulating layer 1 is high-temperature silicon nitride, and the second insulating layer is low-temperature silicon nitride. In addition, the first insulating layer 1 and the second insulating layer 2 may also be other materials.
[0049] In the embodiment of the present application, the material of the electrode 3 includes titanium. In addition, the electrode 3 may also be other materials.
[0050] In the embodiment of the present application, the material of the resistance layer 4 may be a thermistor material or other types of resistance materials. For example, the material of the resistance layer 4 may include vanadium oxide.
[0051] In the present application, a detector may be provided, the detector comprising a plurality of pixel structures (for example, Figure 2 or Figure 3 The pixel structure shown in FIG. 1 ), for example, the plurality of pixel structures may form an array of pixel structures. In some examples, the detector may be an uncooled infrared focal plane detector or other types of detectors.
[0052] The present application also provides a method for manufacturing a pixel structure of a detector, for manufacturing Figure 2 or Figure 3 The pixel structure shown.
[0053] Figure 4 is a schematic diagram of the manufacturing method of the pixel structure. Figure 4 As shown, the method includes:
[0054] 401. Forming a first insulating layer 1;
[0055] 402. Form two electrodes 3 on the surface of the first insulating layer 1;
[0056] 403. Form a second insulating layer 2 on the surface of the first insulating layer 1, and form an opening in the second insulating layer 2, wherein each electrode 3 is at least partially located in the opening, and, in the opening 21, the surface of each electrode 3 is not covered by the second insulating layer 2; and
[0057] 404. A resistance layer 4 is formed on the surface of the first insulating layer 1, wherein the resistance layer 4 is in contact with each electrode 3 in the opening.
[0058] In at least one embodiment of the manufacturing method, the resistance layer 4 is in contact with the surface of the first insulating layer 1 within the opening 21 between the ends of the electrodes 3 that are close to each other.
[0059] In at least one embodiment of the manufacturing method, at least one electrode 3 extends outside the opening 21 and is covered by the second insulating layer 2 .
[0060] In at least one embodiment of the manufacturing method, at least one electrode 3 is entirely located within the opening 21 .
[0061] In at least one embodiment of the manufacturing method, the first insulating layer 1 and the second insulating layer 2 are both silicon nitride, the formation temperature of the first insulating layer 1 is higher than the formation temperature of the second insulating layer 2; and / or, the material of the electrode 3 includes titanium; and / or, the material of the resistance layer 4 includes vanadium oxide.
[0062] The present application is described above in conjunction with specific implementation methods, but it should be clear to those skilled in the art that these descriptions are exemplary and are not intended to limit the scope of protection of the present application. Those skilled in the art can make various modifications and variations to the present application based on the spirit and principles of the present application, and these modifications and variations are also within the scope of the present application.
Claims
1. A pixel structure of a detector, characterized in that: The pixel structure comprises: A first insulating layer (1); A second insulating layer (2) formed on the surface of the first insulating layer (1), wherein the second insulating layer (2) has an opening; Two electrodes (3) are formed on the surface of the first insulating layer (1), each of the electrodes (3) is at least partially located in the opening, and in the opening, the surface of each of the electrodes (3) is not covered by the second insulating layer (2); and A resistance layer (4) is formed on the surface of the first insulating layer (1), and the resistance layer (4) is in contact with each of the electrodes (3) in the opening.
2. The pixel structure according to claim 1, characterized in that: In the opening, between the ends of the electrodes (3) that are close to each other, the resistance layer (4) is in contact with the surface of the first insulating layer (1).
3. The pixel structure according to claim 1, characterized in that: At least one of the electrodes (3) extends outside the opening and is covered by the second insulating layer (2).
4. The pixel structure according to claim 1, characterized in that: At least one of the electrodes (3) is entirely located within the opening.
5. The pixel structure according to any one of claims 1 to 4, characterized in that: The first insulating layer (1) and the second insulating layer (2) are both silicon nitride, and the formation temperature of the first insulating layer (1) is higher than the formation temperature of the second insulating layer (2); and / or The material of the electrode comprises titanium; and / or The material of the resistance layer (4) includes vanadium oxide.
6. A method for manufacturing a pixel structure of a detector, characterized in that: The manufacturing method comprises: forming a first insulating layer (1); Two electrodes (3) are formed on the surface of the first insulating layer (1); A second insulating layer (2) is formed on the surface of the first insulating layer (1), and an opening is formed in the second insulating layer (2), wherein each of the electrodes (3) is at least partially located in the opening, and within the opening, the surface of each of the electrodes (3) is not covered by the second insulating layer (2); and A resistance layer (4) is formed on the surface of the first insulating layer (1), and the resistance layer (4) is in contact with each of the electrodes (3) in the opening.
7. The method for manufacturing a pixel structure according to claim 6, wherein: In the opening, between the ends of the electrodes (3) that are close to each other, the resistance layer (4) is in contact with the surface of the first insulating layer (1).
8. The method for manufacturing a pixel structure according to claim 6, wherein: At least one of the electrodes (3) extends outside the opening and is covered by the second insulating layer (2).
9. The method for manufacturing a pixel structure according to claim 6, wherein: At least one of the electrodes (3) is entirely located within the opening.
10. The method for manufacturing a pixel structure according to any one of claims 6 to 9, characterized in that: The first insulating layer (1) and the second insulating layer (2) are both silicon nitride, and the formation temperature of the first insulating layer (1) is higher than the formation temperature of the second insulating layer (2); and / or The material of the electrode comprises titanium; and / or The material of the resistance layer (4) includes vanadium oxide.