Disclosure of utility model
In order to solve the technical problems, the utility model provides the semiconductor gas sensor based on the micromachining technology, which can ensure that the obtained pattern has higher precision, the consistency of a device and a sensitive material is better, the utilization rate of the sensitive material is higher, the production cost is lower, the material performance of a heating layer is more stable, and the gas sensor has better performance.
The technical application provided by the utility model is as follows:
The utility model provides a semiconductor gas sensor based on a micromachining technology, which comprises a first insulating layer, a heating electrode layer arranged above the first insulating layer, a second insulating layer arranged above the heating electrode layer, an opening structure for passing through bonding wires, a measuring electrode layer arranged above the second insulating layer, a gold electrode layer arranged above the measuring electrode layer, and a sensitive material layer arranged above the gold electrode layer.
Further, in a preferred embodiment of the present utility model, the first insulating layer is specifically a silicon oxide insulating layer film.
Still further, in a preferred form of the utility model, the silicon oxide insulating layer film is specifically a silicon oxide insulating layer film made by a high temperature oxygen-enriched sintering process or a vapor deposition process.
Further, in a preferred embodiment of the present utility model, the heating electrode layer is specifically any one of a platinum micro heater film, a polysilicon semiconductor heater film, and a ruthenium oxide semiconductor heater film.
Still further in a preferred form of the utility model the heater electrode layer is embodied as a heater film made by any one of a magnetron sputtering process, an electron beam deposition process or an ALD process.
Further, in a preferred embodiment of the present utility model, the second insulating layer is specifically a silicon nitride insulating layer film.
Still further, in a preferred embodiment of the present utility model, the silicon nitride insulating layer film is specifically a silicon nitride insulating layer film made by a magnetron sputtering process or a vapor deposition process.
Further, in a preferred mode of the present utility model, the measuring electrode layer is specifically a titanium Jin Cha finger measuring electrode layer or a tantalum nitride finger measuring electrode layer.
Further, in a preferred mode of the utility model, the thickness of the first insulating layer is 70-90 nm, and/or the thickness of the heating electrode layer is 110-130 nm, and/or the thickness of the second insulating layer is 90-110 nm.
Further, in a preferred mode of the utility model, the thickness of the measuring electrode layer is 50-70 nm, and/or the thickness of the gold electrode layer is 110-130 nm, and/or the thickness of the sensitive material layer is 90-110 nm.
In summary, the semiconductor gas sensor based on the micromachining technology comprises a first insulating layer, a heating electrode layer arranged above the first insulating layer, a second insulating layer arranged above the heating electrode layer, an opening structure for passing through bonding wires, a measuring electrode layer arranged above the second insulating layer, a gold electrode layer arranged above the measuring electrode layer, and a sensitive material layer arranged above the gold electrode layer. The heating electrode layer and the sensitive material layer are positioned on the same side, the heating source can directly and rapidly heat the sensitive material, energy loss is reduced, and the heating layer material is wrapped and is not directly exposed to the external environment, so that the performance of the heating layer material is more stable. The utility model not only improves the heating efficiency and reduces the energy consumption required by heating the sensitive material, but also can respond to the target gas more effectively because the heating is quicker and more uniform, thereby improving the utilization rate of the sensitive material. In addition, the micro-processing technology enables the patterning precision of the sensitive material to be higher, the consistency of devices to be better, the material waste possibly occurring in the manufacturing process is reduced, and the effective utilization rate of the sensitive material is indirectly improved. In summary, compared with the prior art, the semiconductor gas sensor based on the micromachining technology provided by the utility model has the advantages that the pattern accuracy is higher, the consistency of the device and the sensitive material is better, the utilization rate of the sensitive material is higher, the production cost is lower, the material performance of the heating layer is more stable, and the gas sensor performance is better.
Detailed Description
In order that those skilled in the art will better understand the technical application of the present utility model, a detailed description of the technical application of the embodiments of the present utility model will be provided with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.
It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element, or be directly connected or indirectly connected to the other element.
It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "first," "second," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate describing the utility model and simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the utility model.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "a plurality" or "a number" means two or more, unless specifically defined otherwise.
It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for the purpose of understanding and reading the disclosure, and are not intended to limit the scope of the utility model, which is defined by the claims, but rather by the claims, unless otherwise indicated, and that any structural modifications, proportional changes, or dimensional adjustments, which would otherwise be apparent to those skilled in the art, would be made without departing from the spirit and scope of the utility model.
As shown in fig. 1 to 3, the semiconductor gas sensor based on the micromachining technology provided by the embodiment of the utility model comprises a first insulating layer 1, a heating electrode layer 2 arranged above the first insulating layer 1, a second insulating layer 3 arranged above the heating electrode layer 2, an opening structure for passing through bonding wires is arranged on the second insulating layer 3, a measuring electrode layer 4 arranged above the second insulating layer 3, a gold electrode layer 5 arranged above the measuring electrode layer 4, and a sensitive material layer 6 arranged above the gold electrode layer 5.
Specifically, in the embodiment of the present utility model, the first insulating layer 1 is specifically a silicon oxide insulating layer, and the thickness of the first insulating layer 1 is 70-90 nm.
Among them, the silicon oxide insulating layer film thickness is more preferably 80nm.
Specifically, in the embodiment of the utility model, the silicon oxide insulating layer film is specifically a silicon oxide insulating layer film manufactured by a high-temperature oxygen-enriched sintering process or a vapor deposition process.
The compactness and stability of the film can be improved by adopting a high-temperature oxygen-enriched sintering process, and the stability of the gas sensor can be ensured by adopting a low-temperature process in a vapor deposition technology to adapt to more types of base materials.
The first insulating layer 1 isolates the silicon chip from the heating electrode layer 2, the silicon chip is conductive to the heating electrode layer 2, the silicon oxide is in the middle to prevent the silicon chip and the heating electrode layer 2 from being contacted and conducted, the silicon chip is placed in a high-temperature pure oxygen environment for 4 hours, the silicon chip can interact with oxygen, and silicon oxide is generated on the surface of the silicon chip. The first insulating layer 1 is used for isolating the silicon chip from the heating electrode layer through the silicon oxide insulating film, so that the stability and the service life of the heating electrode layer are improved, the heating electrode layer is prevented from being directly contacted with the external environment, the performance degradation caused by factors such as oxidization is reduced, and therefore, the gas sensor can keep higher reliability and longer service life in a complex environment, and the consistency and the accuracy of a detection result are ensured.
Specifically, in the embodiment of the present utility model, the heating electrode layer 2 is specifically any one of a platinum micro heater film, a polysilicon semiconductor heater film, or a ruthenium oxide semiconductor heater film.
Specifically, in the embodiment of the utility model, the heating electrode layer 2 is specifically a heater film made by any one of a magnetron sputtering process, an electron beam deposition process or an ALD process.
The utility model greatly optimizes the performance of the gas sensor by adopting a plurality of film deposition technologies such as magnetron sputtering, electron beam deposition, atomic layer deposition and the like. The highly uniform thin film deposition provided by magnetron sputtering ensures uniform distribution of heater material such as polysilicon or RuO2 over the substrate, thereby improving heating efficiency and sensor uniformity. The electron beam deposition enhances the quality of the film due to the high purity and compactness, reduces defects and further improves the reliability and stability of the sensor. The introduction of ALD technology allows precise control of the film thickness layer by layer, achieving uniform coverage even in complex three-dimensional structures, ensuring uniformity of performance of the sensor on a micro scale. In summary, the selection and application of these advanced thin film deposition techniques allows the gas sensor to be significantly optimized in terms of film quality and manufacturing accuracy, thereby improving overall detection performance and lifetime.
Specifically, in the embodiment of the present utility model, the thickness of the heating electrode layer 2 is 110 to 130nm.
Among them, the thickness of the heating electrode layer is more preferably 120nm.
The utility model ensures the stability of the heating performance of the gas sensor in long-term use by selecting polysilicon, ruthenium oxide or platinum as the heater material, wherein the polysilicon heater provides uniform heating effect and maintains structural integrity, the ruthenium oxide heater generates high heat output under low voltage and has good chemical stability, and the platinum heater stably works in various environments with excellent chemical and thermal stability, thereby reducing maintenance requirements and prolonging service life, so that the reliability and accuracy of the sensor are comprehensively improved. In summary, by using polysilicon, ruthenium oxide, or platinum as the heater material, the gas sensor of the present utility model can maintain stability of its heating performance over a long period of use, thereby ensuring reliability and accuracy of the sensor throughout the life cycle, and optimizing applicability and durability of the sensor under various environmental conditions.
Specifically, in the embodiment of the present utility model, the second insulating layer 3 is specifically a silicon nitride insulating layer thin film layer.
And the second insulating layer 3 is etched with an ICP etching machine to ensure good contact between the bonding wires and the heating electrode layer, and meanwhile, damage to surrounding materials is avoided.
Specifically, in the embodiment of the utility model, the silicon nitride insulating layer film is specifically a silicon nitride insulating layer film manufactured by a magnetron sputtering process or a vapor deposition process.
According to the utility model, the heating electrode layer 2 is coated with the SiN insulating layer with the thickness of nm only by adopting a magnetron sputtering mode, the heating electrode layer 2 is coated by the first insulating layer 1 below and the second insulating layer 3 above, so that the direct contact with the external environment is effectively isolated, and meanwhile, the heating rate of the heating electrode layer 2 is faster due to the smaller distance between the heating electrode layer 2 and the measuring electrode layer 4, so that the performance of the gas sensor is optimized.
Specifically, in the embodiment of the present utility model, the thickness of the second insulating layer 3 is 90-110 nm.
Among them, the thickness of the silicon nitride insulating layer film is more preferably 100nm.
Specifically, in the embodiment of the present utility model, the measuring electrode layer 4 is specifically a titanium Jin Cha finger measuring electrode layer or a tantalum nitride finger measuring electrode layer.
In the embodiment of the utility model, the process related to the measuring electrode layer 4 comprises a spin coating process, a laser direct writing process, a manual developing process, an electron beam sputtering process and an NMP stripping process. In the patterning phase, laser direct writing is used for directly forming patterns, spin coating is used for coating photoresist, manual development is used for developing patterns, and NMP stripping is used for removing materials in non-patterned areas.
The spin coating process can uniformly distribute the coating, and is favorable for forming a smooth electrode layer with uniform thickness, so that the consistency and stability of the sensor response are improved; the laser direct writing technology can realize high-precision patterning, is suitable for manufacturing electrodes requiring fine structures and high-resolution patterns, is beneficial to improving the sensitivity and detection precision of the sensor, is high in flexibility, is suitable for small-batch or special-shape design, can meet the requirements of specific sensor design, can provide high-quality thin film deposition, ensures the purity and compactness of electrode materials, is beneficial to improving the reliability and long-term stability of the sensor, and the NMP stripping technology can keep good edge definition when redundant materials are removed, is suitable for application scenes requiring fine edge control, and is beneficial to improving the accuracy and reliability of a measuring electrode layer, thereby improving the performance of the gas sensor.
The measuring electrode layer 4 directly tests the resistance value or the current change of the gas-sensitive material, so that the dense, uniform and consistent measuring electrode layer 4 can effectively reduce the resistance of the sensitive material layer 6 and rapidly and effectively detect the resistance value or the current change of the sensitive material layer 6. The interdigital electrodes of TaN and TiAu are covered on the surface of the insulating layer by adopting the modes of spin coating, laser direct writing, manual development, electron beam sputtering and NMP stripping, the interdigital electrodes obtained by the micromachining process have higher density and better size uniformity, and the distance between the interdigital electrodes can be at least several um levels.
The interdigital electrodes of the measuring electrode layer 4 are spaced by a plurality of um levels, the interdigital electrodes are spaced by a plurality of um levels, the structure is dense, uniform and consistent, compared with the traditional structure, the interdigital electrodes are better, and the resistance change of the sensitive material layer can be detected rapidly and effectively. Because the resistance change reflects the instant change of the gas composition or concentration, the changes are captured faster and more accurately, so that the sensor can provide reliable detection data in real time, and the sensor is suitable for application scenes needing instant response. Therefore, the dense, uniform and consistent interdigital electrode structure can improve the response speed and the detection precision of the gas sensor.
Specifically, in the embodiment of the present utility model, the thickness of the measuring electrode layer 4 is 50-70 nm.
Among them, titanium Jin Cha is more preferable to refer to the thickness of the measuring electrode layer as 60nm.
Specifically, in the embodiment of the present utility model, the thickness of the gold electrode layer 5 is 110 to 130nm.
Among them, the gold electrode layer 5 is more preferably 120nm thick.
Specifically, in the embodiment of the present utility model, the gold electrode layer 5 is applied on the measuring electrode layer 4 by printing, and the shape and size of the gold electrode layer are kept consistent with those of the measuring electrode layer 4 by etching.
Specifically, in the embodiment of the present utility model, the thickness of the sensitive material layer 6 is 90-110 nm.
Of these, it is more preferable that the thickness of the sensitive material layer 6 is 100um.
Specifically, in the embodiment of the present utility model, the sensitive material layer 6 is printed on the sensor, and in the embodiment of the present utility model, the sensitive material of the sensitive material layer 6 is specifically a tin oxide semiconductor.
After the sensor is manufactured, the sensitive material layer 6 is printed on the sensor, and finally, the corresponding welding is finished, namely, the manufacturing of the whole gas sensor is finished.
The scheme provided by the embodiment of the utility model realizes uniform distribution of the sensitive material by a screen printing technology, improves the material utilization rate and reduces the production cost. In addition, by combining micromachining and printing processes, the response speed and sensitivity of the sensor are improved, and the detection performance of the sensor is enhanced.
The utility model can be seen from the above, the micro-machined silicon oxide insulating layer film is adopted to isolate the heating electrode layer, prevent the heating electrode layer from conducting and protect the heating electrode layer from being in direct contact with air, the micro-machined platinum micro-heater film is adopted to provide high temperature to keep the best sensitivity characteristic, the micro-machined silicon nitride insulating layer film is adopted to isolate the heating electrode layer from the measuring electrode layer, prevent the heating electrode layer from being in direct contact with the measuring electrode layer, the micro-machined titanium Jin Cha is adopted to refer to the measuring electrode layer, the resistance change is detected quickly and effectively, and the gold electrode layer combined with the micro-machining technology and the printing technology is adopted to accurately test the current or resistance change.
The semiconductor gas sensor based on the micro-machining technology provided by the utility model has the advantages that the sensitive material layer and the heating electrode layer are positioned on the same side, the pattern precision obtained by the micro-machining technology is higher, the consistency of a device and the sensitive material is better, the sensor can provide a high-resolution gas concentration detection result by the high-precision micro-machining technology, the detection accuracy and sensitivity are improved, the sensor can rapidly respond to the change of the gas concentration by using the optimized heater design and the high-conductivity material, the response time is shortened, the sensor can still maintain the initial performance in long-term use by adopting a multi-layer structure and high-quality material, and the maintenance and calibration requirements are reduced. The high-precision micromachining is combined with the traditional screen printing process, so that the utilization rate of sensitive materials is increased, the production cost is reduced, and the heating layer material is completely wrapped and is not exposed in the air, so that the heating layer material has more stable performance, can be heated more quickly, and improves the performance of the semiconductor gas sensor. In summary, the gas sensor of the utility model not only can reliably work in various complex environments, but also has the characteristics of high-precision detection, quick response, long-term stability, cost effectiveness and the like, so that the gas sensor has higher application value.
More specifically, the sensor structure widely used in the market at present is a by-pass type structure, wherein the most common is a planar by-pass type structure, namely, a heating layer material is positioned on one side of a ceramic plate, and a heating electrode and a measuring electrode are positioned on the other side of the ceramic plate. In addition, the conventional measuring electrode has a large size, which adversely affects the resistance of the semiconductor type gas sensor.
Based on the prior art, the gas sensor structure provided by the utility model has the advantages that the sensitive material and the heating electrode are positioned on the same side, the precision of patterns is improved through a micro-processing technology, so that the consistency of a device and the sensitive material is better, the utilization rate of the sensitive material is increased, the production cost is reduced, the heating layer material is completely wrapped and is not directly exposed to the air, so that the performance of the heating layer material is more stable, the sensitive material can be heated more quickly, and the overall performance of the semiconductor gas sensor is improved.
The embodiment of the utility model provides a scheme for manufacturing a semiconductor gas sensor structure based on a micro-machining technology, and aims to improve the precision, the product consistency and the stability of sensor production and obviously reduce the production cost by combining the micro-machining technology with a traditional screen printing technology.
More specifically, the utility model provides a novel semiconductor resistance type gas sensor structure and a micromachining manufacturing process scheme thereof, and the obtained semiconductor gas sensor has the advantages of simple structure, stable performance and low production cost, and has higher application value in the field of inflammable, explosive, toxic and harmful gas detection. In order to achieve the above object, the novel structural technical scheme of the present utility model is completed by a micromachining technology in combination with a screen printing process. The first insulating layer 1 designed in the embodiment of the utility model is a silicon oxide insulating layer film adopting a micro-processing technology, the thickness of the insulating layer is 80nm, and the insulating layer is positioned at the lowest part, and the insulating layer mainly has the functions of isolating the heating electrode, preventing the heating electrode from being conducted and protecting the heating electrode from being in direct contact with air. The insulating medium layer can be insulating materials such as silicon oxide, and the film can be processed by adopting a high-temperature oxygen-enriched sintering process or a vapor deposition process.
The heating electrode layer 2 designed in the embodiment of the utility model is a platinum micro-heater film adopting micro-processing technology, preferably 120nm in thickness, and is located on the first insulating layer 1, and the main function of the heating electrode layer is to provide high temperature for sensitive materials to keep optimal sensitive characteristics, the micro-heater material can also be a polycrystalline silicon or ruthenium oxide semiconductor heater, and the film can be made by any one of magnetron sputtering technology, electron beam deposition technology or atomic layer deposition technology.
The second insulating layer 3 designed in the embodiment of the utility model is a silicon nitride insulating layer film with the thickness of preferably 100nm and is positioned on the heating electrode layer 2, and the second insulating layer is mainly used for isolating the heating electrode layer 2 from the measuring electrode layer 4 and preventing the heating electrode layer 2 from being directly contacted with the measuring electrode layer 4. Meanwhile, the insulating layer is required to be perforated so that the bonding wires are in direct contact with the heating electrode, the insulating layer film can be processed by adopting a magnetron sputtering process or a vapor deposition process, and an ICP etching machine can be used for etching the perforated.
Furthermore, the measuring electrode layer 4 designed in the embodiment of the utility model is a titanium Jin Cha finger measuring electrode adopting a micro-processing technology, the thickness is preferably 60nm, the inter-finger electrode interval is a plurality of micrometers, the structure is dense, uniform and consistent, compared with the traditional structure, the main function is to rapidly and effectively detect the resistance change of sensitive materials. The measuring electrode is positioned on the second insulating layer 3, the measuring electrode material can also be tantalum nitride, and the interdigital measuring electrode layer is manufactured by adopting a spin coating process, a laser direct writing process, a manual developing process, an electron beam sputtering process and an NMP stripping process.
Further, the gold electrode layer 5 designed in the embodiment of the present utility model is made by combining micro-machining technology and printing technology, preferably 120nm thick, and is located on the measuring electrode layer 4, and its main function is to accurately test the current or resistance change of the sensitive material. The gold electrode layer 5 is applied onto the measuring electrode layer 4 by printing and the shape and size are kept completely consistent with the measuring electrode layer 4 by etching.
Further, the thickness of the sensitive material layer 6 according to the embodiment of the present utility model is preferably 100 μm, and the sensitive material layer is located on the gold electrode layer 5, which is mainly used for measuring the concentration and composition of the gas. After the sensor is manufactured, sensitive materials can be printed on the sensor in a printing mode, and finally corresponding welding is finished, so that the manufacturing of the whole gas sensor is finished.
In summary, the technical scheme provided by the embodiment of the utility model designs a brand new planar side heating type gas sensor, which is applicable to various semiconductor type gas sensors, has important application value in the aspect of gas detection in a complex environment, and has important commercial value for practical application of the semiconductor type gas sensor.
The semiconductor gas sensor based on the micromachining technology takes the tin oxide semiconductor as a sensitive material, and the sensitive materials with the same thickness are printed on the micromachined sensor and the traditional structure sensor provided by the scheme respectively, and the two structures are subjected to power-on stability test. The specific results are shown in the figure 3, and the test results show that compared with the traditional structure in the prior art, under the condition that sensitive materials are the same, the micro-machined sensor structure is used, the air resistance is lower than that of the sensor with the traditional structure, the power-on stabilization time is shorter, the stability can be achieved within half an hour, the use efficiency of the sensor is optimized, and the structure has more excellent performance for the semiconductor type gas sensor.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the utility model. Thus, the present utility model is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.