Uncooled infrared chip

Abstract

The utility model relates to the field of uncooled infrared chips, in particular to an uncooled infrared chip, which comprises a readout circuit, a pixel microbridge arranged above the readout circuit, a metal electrode arranged between the readout circuit and the pixel microbridge and composed of two layers of metal titanium and two layers of metal aluminum. The metal aluminum is arranged between the two groups of metal titanium; on the other hand, the metal titanium is more stable and antioxidant than the metal aluminum, the metal titanium cannot be passivated after repeated wet photoresist removing and cleaning, and can be in good contact with the metal titanium on the upper layer, so that dead pixels in a direct-current level test cannot be generated, and on the other hand, due to the fact that the thickness of the third layer of metal titanium is 150-250A, reflection of infrared light cannot be weakened.

Description

TECHNICAL FIELD

[0001] The utility model relates to non refrigeration infrared chip field, concretely is a non refrigeration infrared chip. BACKGROUND

[0002] At present, the metal electrode material connected with CMOS Wplug in the lowermost layer of non refrigeration infrared chip MEMS structure is Ti-Al, wherein the thickness of the first layer metal Ti is 200A, the thickness of the second layer metal Al is 3000A, and the film layer is completed by physical vapor deposition technology once deposition, after the pattern etching is completed, a part is used as the metal electrode connected with CMOS Wplug, and the other part is used as the infrared reflecting layer of the pixel;

[0003] In production test, it is found that the Ti-Al metal electrode is oxidized to form a passivation layer film on the surface of metal Al after the pattern etching is completed, which leads to poor contact with the upper metal Ti, thereby increasing the contact resistance or leading to open circuit, and forming the direct current level test bad point. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a kind of non refrigeration infrared chip to solve the problems raised in the above background.

[0005] To achieve the above object, the utility model provides the following technical scheme:

[0006] A kind of non refrigeration infrared chip, comprising:

[0007] Readout circuit (1), the readout circuit (1) is provided with pixel microbridge (2) above, and metal electrode (8) is provided between the readout circuit (1) and the pixel microbridge (2), the metal electrode (8) includes metal titanium layer (81) and metal aluminum layer (82), the metal titanium layer (81) is provided with two layers, and the metal aluminum layer (82) is arranged between two metal titanium layers (81).

[0008] Preferably, the metal tungsten (9) is arranged between the lowermost metal titanium layer (81) and the readout circuit (1), the metal tungsten (9) is electrically connected with the lowermost metal titanium layer (81), and the metal tungsten (9) is located in the inside of the readout circuit (1).

[0009] Preferably, the pixel microbridge (2) includes first bridge column supported above the metal electrode (8), bridge leg connected with the top of first bridge column, second bridge column supported above bridge leg and bridge surface connected with the top of second bridge column.

[0010] The first bridge column and the bridge leg and the second bridge column of the pixel micro-bridge (2) each comprise a titanium coating (3) and a silicon nitride coating (4), the silicon nitride coating (4) is located outside the titanium coating (3), and the titanium coating (3) on the first bridge column is in conduction with the uppermost metal titanium layer (81) of the metal electrode (8).

[0011] Preferably, the metal electrode (8) has two, and the two metal electrodes (8) have a mirror, the material of the mirror is the same as that of the metal electrode (8).

[0012] Preferably, the bridge surface of the pixel micro-bridge (2) comprises a vanadium oxide coating (7) and silicon nitride coatings (4) located on the upper and lower sides of the vanadium oxide coating (7).

[0013] Preferably, the outer surface of the silicon nitride coating (4) on the upper side of the vanadium oxide coating (7) has a titanium nitride coating (5), the titanium nitride coating (5) and the silicon nitride coating (4) on the upper side of the vanadium oxide coating (7) cooperate with each other to perform infrared absorption.

[0014] Preferably, the vanadium oxide coating (7) of the bridge surface of the pixel micro-bridge (2) is connected with titanium coatings (3) at both ends.

[0015] Preferably, the vanadium oxide coating (7) of the bridge surface of the pixel micro-bridge (2) has a silicon oxide coating (6) above, and the silicon oxide coating (6) is located between the vanadium oxide coating (7) and the silicon nitride coating (4).

[0016] Preferably, the thickness of the metal titanium layer is between 150-250A.

[0017] Preferably, the thickness of the metal aluminum layer is between 250-350A.

[0018] Compared with the prior art, the beneficial effects of the present application are:

[0019] Since the metal titanium is more stable and resistant to oxidation than the metal aluminum, after multiple wet degreasing and cleaning, the metal titanium will not be passivated and can be in good contact with the infrared micro-bridge, so that the direct current level test bad point will not be generated. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure section of the present application;

[0021] Figure 2 It is a schematic diagram of the metal electrode structure section of the present application.

[0022] In the figure: readout circuit 1, pixel microbridge 2, titanium coating 3, silicon nitride coating 4, titanium nitride coating 5, silicon oxide coating 6, vanadium oxide coating 7, metal electrode 8, metal titanium layer 81, metal aluminum layer 82, metal tungsten 9. DETAILED DESCRIPTION

[0023] In order to more clearly illustrate the overall concept of the present application, the following will be described in detail in conjunction with the accompanying drawings.

[0024] It should be noted that in the following description, many specific details are set forth in order to provide a thorough understanding of the present application, however, the present application can be practiced in other ways different from those described herein, therefore, the scope of protection of the present application is not limited by the specific embodiments disclosed below.

[0025] In addition, in the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0026] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. However, it is noted that direct connection means that the connection between the two main bodies does not form a connection relationship through an excessive structure, but is connected only through the connection structure to form a whole. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples.

[0028] Embodiment one:

[0029] Please refer to Figures 1-2 The present application provides a technical solution: a non-refrigeration infrared chip, comprising:

[0030] The readout circuit 1 is provided with a pixel micro-bridge 2 above, and a metal electrode 8 is arranged between the readout circuit 1 and the pixel micro-bridge 2, the metal electrode 8 comprises a metal titanium layer 81 and a metal aluminum layer 82, the metal titanium layer 81 is provided with two layers, and the metal aluminum layer 82 is arranged between the two metal titanium layers 81;

[0031] The thickness of the metal titanium 81 is 150-250A, preferably 200A;

[0032] The thickness of the metal aluminum 82 is 250-350A;

[0033] The thickness of the two metal titanium layers 81 is 150-250A, and the thickness of the metal aluminum 82 is 250-350A, which is completed by physical vapor deposition technology at one time;

[0034] Because the metal titanium 81 is more stable and resistant to oxidation than the metal aluminum 82, it will not be passivated after multiple wet degreasing and cleaning, and can be in good contact with the titanium coating on the pixel micro-bridge 2, so that no bad points will be produced in direct current level test. On the other hand, because the thickness of the lower metal titanium 81 is only 150-250A, the reflection of infrared light will not be weakened.

[0035] Embodiment two:

[0036] As Figure 1 shown, the non-refrigeration infrared chip disclosed in the second embodiment of the present application has basically the same structure as that in the first embodiment, and the difference lies in that:

[0037] The pixel micro-bridge 2 comprises a first bridge column supported above the metal electrode 8, a bridge leg connected to the top of the first bridge column, a second bridge column supported above the bridge leg, and a bridge surface connected to the top of the second bridge column;

[0038] The first bridge column and the bridge leg and the second bridge column of the pixel micro-bridge 2 each comprise a titanium coating 3 and a silicon nitride coating 4, the silicon nitride coating 4 is located outside the titanium coating 3, and the titanium coating 3 on the first bridge column is in conduction with the uppermost metal titanium layer 81 of the metal electrode 8;

[0039] The metal electrode 8 has two, and the two metal electrodes 8 have a mirror, and the material of the mirror is the same as that of the metal electrode 8;

[0040] The bridge surface of the pixel micro-bridge 2 comprises a vanadium oxide coating 7 and a silicon nitride coating 4 located on both sides of the vanadium oxide coating 7;

[0041] The outer surface of the silicon nitride coating 4 on the upper side of the vanadium oxide coating 7 has a titanium nitride coating 5, which cooperates with the silicon nitride coating 4 on the upper side of the vanadium oxide coating 7 to perform infrared absorption;

[0042] The two ends of the vanadium oxide coating 7 of the bridge surface of the pixel micro-bridge 2 are connected with titanium coatings 3;

[0043] The bridge surface of the pixel micro-bridge 2 has a silicon oxide coating 6 above the vanadium oxide coating 7, and the silicon oxide coating 6 is located between the vanadium oxide coating 7 and the silicon nitride coating 4;

[0044] The pixel micro-bridge 2 is made by MEMS (Micro Electro Mechanical System) process.

[0045] The titanium coating 3 inside the first bridge column of the pixel micro-bridge 2 mainly plays a conduction role, the silicon nitride coating 4 on the outer surface of the first bridge column of the pixel micro-bridge 2 mainly plays a supporting role, and the titanium nitride coating 5 on the outer surface of the bridge surface of the pixel micro-bridge 2 cooperates with the silicon nitride coating 4 coated on the outer surface of the bridge surface to perform infrared absorption, while the vanadium oxide coating 7 can sense the change of external heat, and the silicon oxide coating 6 protects the vanadium oxide coating 7.

[0046] It should be understood by those skilled in the art that the discussion of any of the above embodiments is only exemplary and is not intended to limit the scope of the present application (including claims) to these examples; under the idea of the present application, the above embodiments or technical features in different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the present application as described above. In order to be brief, they are not provided in detail.

[0047] The present application is intended to cover all such alternatives, modifications, and variations that fall within the broad scope of the appended claims. Accordingly, any and all such alternations, modifications, equivalents, improvements and the like are intended to be encompassed by the present application.

Claims

1. An uncooled infrared chip, characterized in that, include: A readout circuit (1) is provided above the readout circuit (1), and a metal electrode (8) is provided between the readout circuit (1) and the pixel microbridge (2). The metal electrode (8) includes a titanium layer (81) and an aluminum layer (82). The titanium layer (81) is provided in two layers, and the aluminum layer (82) is provided between the two titanium layers (81).

2. The uncooled infrared chip according to claim 1, characterized in that, A tungsten metal (9) is disposed between the bottom titanium layer (81) and the readout circuit (1). The tungsten metal (9) is electrically connected to the bottom titanium layer (81) and is located inside the readout circuit (1).

3. The uncooled infrared chip according to claim 1, characterized in that, The pixel microbridge (2) includes a first bridge post supported above the metal electrode (8), a bridge leg connected to the top of the first bridge post, a second bridge post supported above the bridge leg, and a bridge surface connected to the top of the second bridge post. The first bridge post and the second bridge post of the pixel microbridge (2) all include a titanium coating (3) and a silicon nitride coating (4). The silicon nitride coating (4) is located outside the titanium coating (3), and the titanium coating (3) on the first bridge post is connected to the uppermost titanium layer (81) of the metal electrode (8).

4. The uncooled infrared chip according to claim 1, characterized in that, There are two metal electrodes (8), and a reflector is provided between the two metal electrodes (8). The reflector is made of the same material as the metal electrodes (8).

5. The uncooled infrared chip according to claim 3, characterized in that, The bridge surface of the pixel microbridge (2) includes a vanadium oxide coating (7) and silicon nitride coatings (4) located on the upper and lower sides of the vanadium oxide coating (7).

6. The uncooled infrared chip according to claim 5, characterized in that, The outer surface of the silicon nitride coating (4) located on the upper side of the vanadium oxide coating (7) has a titanium nitride coating (5). The titanium nitride coating (5) and the silicon nitride coating (4) on the upper side of the vanadium oxide coating (7) cooperate with each other to perform infrared absorption.

7. The uncooled infrared chip according to claim 5, characterized in that, The vanadium oxide coating (7) on the surface of the pixel microbridge (2) is connected to titanium coating (3) at both ends.

8. The uncooled infrared chip according to claim 5, characterized in that, The pixel microbridge (2) has a silicon oxide coating (6) above the vanadium oxide coating (7) on its bridge surface, and the silicon oxide coating (6) is located between the vanadium oxide coating (7) and the silicon nitride coating (4).

9. The uncooled infrared chip according to claim 2, characterized in that, The thickness of the titanium layer (81) is between 150 and 250 Å.

10. The uncooled infrared chip according to claim 2, characterized in that, The thickness of the aluminum layer (82) is between 250 and 350 Å.

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