阅读说明：本技术 电阻式氢气传感器及其制备方法 (Resistance type hydrogen sensor and preparation method thereof ) 是由 肖韩 宋华威 王荣 于 2020-12-22 设计创作，主要内容包括：本申请涉及半导体技术领域,具体涉及一种电阻式氢气传感器及其制造方法,包括:衬底；电极层,形成在所述衬底上,包括第一电极以及第二电极；氢气敏感层,形成在所述电极层上,并与所述第一电极以及第二电极构成三明治状的电阻结构,所述氢气敏感层为网状结构的聚合物膜。本发明采用网状结构的聚合物膜作为氢气敏感层,这样氢气敏感层可以具有足够高的氢气渗透性,使得电阻式氢气传感器的灵敏度更高,响应速度更快,此外,本实施例中的制造工艺可以与CMOS工艺平台完美兼容,大大缩小了器件的尺寸,易于与集成电路芯片结合。(The application relates to the technical field of semiconductors, in particular to a resistance type hydrogen sensor and a manufacturing method thereof, which comprises a substrate; an electrode layer formed on the substrate and including a first electrode and a second electrode; and the hydrogen sensitive layer is formed on the electrode layer and forms a sandwich-shaped resistance structure with the first electrode and the second electrode, and the hydrogen sensitive layer is a polymer film with a net structure. The invention adopts the polymer film with the net structure as the hydrogen sensitive layer, so that the hydrogen sensitive layer can have high enough hydrogen permeability, the sensitivity of the resistance-type hydrogen sensor is higher, and the response speed is faster.)

1. A resistive hydrogen sensor, comprising:

a substrate;

an electrode layer formed on the substrate and including a first electrode and a second electrode;

and the hydrogen sensitive layer is formed on the electrode layer and forms a sandwich-shaped resistance structure with the first electrode and the second electrode, and the hydrogen sensitive layer is a polymer film with a net structure.

2. The resistive hydrogen sensor of claim 1 wherein the polymer membrane is selected from the group consisting of microporous polymer membranes, facilitated transport polymer membranes, langmuir-blodgett membranes, layer-by-layer self-assembled polyelectrolyte multilayer membranes, polyamide-based membranes, and metal-organic framework membranes in combination with one or more.

3. The resistive hydrogen sensor of claim 1 wherein the substrate is a circuit-fabricated silicon substrate for CMOS front-end and partial back-end processing; or the substrate is made of silicon wafer, glass or ceramic substrate, and an insulating layer is deposited to be processed to be used as the MEMS discrete device.

4. A capacitive hydrogen sensor according to claim 1,

the electrode layer further comprises a third electrode, and the third electrode fully surrounds or semi-surrounds the first electrode and the second electrode.

5. The resistive hydrogen sensor of claim 4, further comprising:

an insulating layer formed on the substrate, the electrode layer being formed on the insulating layer;

the pressing welding layer is formed on the insulating layer and is used for connecting an external lead;

and the passivation layer is formed on the third electrode area of the electrode layer and the press welding layer.

6. The resistive hydrogen sensor of claim 5, wherein the material of the electrode layer is selected from the group consisting of: one or more of aluminum, aluminum silicon and aluminum copper; the passivation layer is silicon dioxide, silicon nitride or a compound of the silicon dioxide and the silicon nitride.

7. The resistive hydrogen sensor of claim 5 wherein the first and second electrodes are spaced apart by a width of 1-10 μm; the thickness of the electrode layer is 0.1-5 μm, the thickness of the passivation layer is 0.5-5 μm, and the thickness of the hydrogen sensitive layer is 1-10 μm.

8. A method for manufacturing a resistive hydrogen sensor, comprising the steps of:

providing a substrate, and sequentially depositing an insulating layer on the substrate;

depositing an electrode layer on the insulating layer, and defining the areas of the first electrode, the second electrode and the pressure welding block;

depositing a passivation layer on the electrode layer, completely removing the passivation layers of the first electrode area and the second electrode area, and reserving a third electrode area and other passivation layers of a connecting circuit to form a hydrogen detection area of the sensitive resistor;

forming a pressure welding block area;

and coating a hydrogen sensitive layer, removing the hydrogen sensitive layer on the pressure welding block, reserving the hydrogen sensitive layer between the first electrode and the second electrode and part of the hydrogen sensitive layer on the passivation layer, and finally curing to finish the manufacture of the resistance-type hydrogen sensor.

9. The method of claim 8, wherein removing the passivation layer between the first and second electrodes comprises: removing the surfaces and the side walls of the first electrode and the second electrode and the passivation layer between the first electrode and the second electrode until the insulating layer is etched;

the sensitive capacitance detection electrode area and the bonding pad area are formed simultaneously, or the bonding pad area is formed after the sensitive capacitance detection electrode area is formed.

10. The method of claim 8, wherein the resistive hydrogen sensor is compatible with a CMOS process.

Technical Field

The application relates to the technical field of semiconductors, in particular to a resistance type hydrogen sensor and a preparation method thereof.

Background

In the field of new energy, hydrogen fuel is widely applied to the fields of aerospace, aviation and automobiles due to the advantages of no pollution, no noise, high efficiency and the like, so that the change of the hydrogen concentration of the environment needs to be detected or detected, and faults or abnormal states need to be responded to in time. At present, hydrogen fuel cell vehicles are generally provided with a hydrogen sensor or a hydrogen leakage detection device to detect the change of the environmental hydrogen concentration.

The traditional hydrogen sensor is of a resistance type, electrons in hydrogen are combined with oxygen ions in a chemical adsorption layer of the hydrogen sensor, and therefore the concentration of the hydrogen in the environment is detected through the change of the concentration of carriers.

Disclosure of Invention

The present application addresses, at least to some extent, the above-mentioned technical problems in the related art. Therefore, the present application provides a resistive hydrogen sensor and a method for manufacturing the same to solve at least one of the above technical problems.

In order to achieve the above object, a first aspect of the present application provides a resistive hydrogen sensor comprising:

a substrate;

an electrode layer formed on the substrate and including a first electrode and a second electrode;

and the hydrogen sensitive layer is formed on the electrode layer and forms a sandwich-shaped resistance structure with the first electrode and the second electrode, and the hydrogen sensitive layer is a polymer film with a net structure.

In a second aspect, the present application provides a method for manufacturing a resistive hydrogen sensor, including the following steps:

providing a substrate, and sequentially depositing an insulating layer on the substrate;

depositing an electrode layer on the insulating layer, and defining the areas of the first electrode, the second electrode and the pressure welding block;

depositing a passivation layer on the electrode layer, completely removing the passivation layers of the first electrode area and the second electrode area, and reserving a third electrode area and other passivation layers of a connecting circuit to form a hydrogen detection area of the sensitive resistor;

forming a pressure welding block area;

and coating a hydrogen sensitive layer, removing the hydrogen sensitive layer on the pressure welding block, reserving the hydrogen sensitive layer between the first electrode and the second electrode and part of the hydrogen sensitive layer on the passivation layer, and finally curing to finish the manufacture of the resistance-type hydrogen sensor.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

fig. 1 is a schematic structural cross-sectional view illustrating a MEMS resistive hydrogen sensor according to an embodiment of the present invention.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood that the description is illustrative only and is not intended to limit the scope of the present disclosure. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure.

Various structural schematics according to embodiments of the present disclosure are shown in the figures. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers, and relative sizes and positional relationships therebetween shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, as actually required.

In the context of the present disclosure, when a layer/element is referred to as being "on" another layer/element, it can be directly on the other layer/element or intervening layers/elements may be present. In addition, if a layer/element is "on" another layer/element in one orientation, then that layer/element may be "under" the other layer/element when the orientation is reversed.

As shown in fig. 1, the present embodiment provides a Micro-electromechanical (MEMS) resistive hydrogen sensor 100, which includes a substrate 10, an insulating layer 11, an electrode layer 14, a bonding layer 15, a passivation layer 16, and a hydrogen sensitive layer 17, wherein the insulating layer 11 is formed on the substrate 10, the electrode layer 14 is formed on the insulating layer 11, and the electrode layer 14 includes a first electrode 140, a second electrode 141, and a third electrode 142.

Further, a bonding layer 15 is formed on the insulating layer 11 for connecting an external wire, and a passivation layer 16 is formed on the third electrode 142 region of the electrode layer 14, the exposed insulating layer 11, and the bonding layer 15.

It should be noted that the hydrogen sensitive layer 17 includes a portion formed between the first electrode 140 and the second electrode 141 and a portion formed on the electrode layer 14, and forms a sandwich-like resistance structure with the first electrode 140 and the second electrode 141, and the hydrogen sensitive layer is a polymer film with a mesh structure.

It should be noted that the hydrogen sensitive layer 17 is a polymer film with a mesh structure, so that the hydrogen sensitive layer 17 can have a sufficiently high hydrogen permeability, so that the sensitivity of the resistive hydrogen sensor 100 is higher and the response speed is faster. Specifically, the polymer film may be selected from one or more of microporous polymer films (microporus polymers), facilitated transport polymer films (functionalized polymeric membranes), Langmuir-Blodgett films (LB), Layer-by-Layer self-assembled polyelectrolyte multilayers (PEMs), polyamide films (polyamides), and metal-organic framework films (MOFs).

In some embodiments of the present invention, the substrate 10 is a silicon substrate of a CMOS front-end and partial back-end process in which circuits have been processed; or the substrate 10 is made of silicon wafer, glass or ceramic substrate, and is processed by depositing an insulating layer to be used as an MEMS discrete device; the material of the electrode layer 14 is one or more of the following materials: aluminum, aluminum silicon, aluminum copper, the passivation layer 16 may be silicon dioxide, silicon nitride, or a composite thereof.

In the embodiment of the present invention, the substrate 10 is a silicon wafer, and the insulating layer 11 is an oxide layer. The electrode layer 14 is an aluminum layer and is defined as a sensitive capacitance detection electrode region, a shielding region and a bonding layer region. The passivation layer 16 may be a composite layer of silicon dioxide and silicon nitride, and the hydrogen sensitive layer 17 may be a microporous polymer film.

The manufacturing process of the MEMS resistive hydrogen sensor 100 in this embodiment is as follows:

s1: preparing a silicon wafer substrate 10, and depositing an insulating layer 11 on the wafer; the insulating layer 11 is made by growing silicon oxide by thermal oxidation, or depositing silicon oxide or silicon nitride by a CVD process, or a composite layer thereof.

S2: depositing a layer of aluminum on the insulating layer 11 as an electrode layer 14 by a magnetron sputtering or evaporation process, and further defining a first electrode 140, a second electrode 141, a third electrode 142 and a bonding layer 15 by a photoetching and etching process; the thickness of the electrode layer 14 is 0.1-5 μm. The interval width between the first electrode 140 and the second electrode 141 is 1-10 μm.

S3: depositing a passivation layer 16 on the electrode layer 14 by a PECVD process, further completely removing the passivation layer 16 in the first electrode and the second electrode regions by photoetching and etching processes, and reserving a third electrode region and other passivation layers 16 connected with a circuit to form a sensitive capacitance detection electrode region; the thickness of the passivation layer 16 is 0.5-5 μm. Preferably, the passivation layer 16 of the first and second electrode regions is etched by a dry etching technique, and the surfaces and sidewalls of the first and second electrodes 140 and 141 and the passivation layer 16 between the first and second electrodes 140 and 141 are etched clean.

S4: the pad areas are formed by pad lithography and the passivation layer 16 is etched to open the pad layer 15. Obviously, it is also possible to open the bonding layers 15 at the same time in the step S3, omitting the step S4, i.e., the sensitive capacitance detecting electrode area and the pad area are formed at the same time, or the pad area is formed after the sensitive capacitance detecting electrode area is formed.

S5: coating a microporous polymer film as a hydrogen sensitive layer 17, removing the hydrogen sensitive layer 17 on the press welding layer 15 through processes such as photoetching and developing, and finally curing to complete the manufacture of the MEMS resistance-type hydrogen sensor 100, wherein the thickness of the cured hydrogen sensitive layer 17 is 1-10 microns.

Compared with the prior art, the polymer film with the net structure is used as the hydrogen sensitive layer, so that the hydrogen sensitive layer can have high enough hydrogen permeability, the sensitivity of the resistance-type hydrogen sensor is higher, the response speed is higher, and it is worth mentioning that the manufacturing process in the embodiment can be perfectly compatible with the CMOS process, the size of the device is greatly reduced, and the device is easy to be combined with an integrated circuit chip.

In the above description, the technical details of patterning, etching, and the like of each layer are not described in detail. It will be appreciated by those skilled in the art that layers, regions, etc. of the desired shape may be formed by various technical means. In addition, in order to form the same structure, those skilled in the art can also design a method which is not exactly the same as the method described above. In addition, although the embodiments are described separately above, this does not mean that the measures in the embodiments cannot be used in advantageous combination.

The embodiments of the present disclosure have been described above. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. The scope of the disclosure is defined by the appended claims and equivalents thereof. Various alternatives and modifications can be devised by those skilled in the art without departing from the scope of the present disclosure, and such alternatives and modifications are intended to be within the scope of the present disclosure.