Micro-bridge unit for micrometering radiant heat, array structure of micro-bridge unit and manufacturing method of micro-bridge unit

Abstract

The invention discloses a micro-bridge unit for micro-measuring radiant heat, an array structure of the micro-bridge unit and a manufacturing method of the micro-bridge unit. Four bridge piers of a plurality of micro-bridge units in a rectangular array are respectively arranged close to two opposite edges of a corresponding substrate in a manner that every two bridge piers form a group; the interval between the two bridge piers of each group is controlled to be the minimum value under the condition that the manufacturing process is allowed in the length direction of the corresponding edge; the two groups of piers are connected with a bridge surface arranged between the two groups of piers through two groups of bridge arms symmetrically arranged according to the center of the substrate; the two concave structures of the two first bridge arms and the irregular structures of the two second bridge arms of the two sets of bridge arms form a rectangular frame on the periphery of the bridge floor. Each concave structure is connected with the corresponding pier through a first H-shaped structure; and each irregular structure is connected with the corresponding pier through a second H-shaped structure. And during multiple constructions, multiple film layers are deposited one by one, and photoetching etching is carried out. The application of the invention can give consideration to both microbridge support stability and reasonable layout of the sensitive layer.

Description

Technical Field

[0001] This invention relates to the field of microthermometry device manufacturing technology, and particularly to microbridge units for microthermometry, their array structures, and manufacturing methods. Background Technology

[0002] The thermistor effect, which is based on the change in resistance of the detection material with thermal properties when the temperature changes, is a technology widely used in various micro-radiative thermal measurement fields. Its unit usually adopts a microbridge structure, and the microbridge support structure is formed by using a sacrificial layer release process. The thermistor material on the microbridge surface is connected to the substrate readout circuit through the microbridge.

[0003] In terms of structural design, on the one hand, to ensure high sensitivity of the microbolometer, the microbridge needs excellent thermal insulation. The conventional method is to select suitable insulation materials (such as silicon nitride, silicon oxide, or silicon oxynitride) as the support layer and design slender supporting arms between the piers and the bridge deck. On the other hand, to maximize the absorption of radiant heat by the microbolometer, the bridge deck needs to be flat, which in turn requires sufficient supporting strength in the arms, while simultaneously ensuring stress balance among the various membrane layers. These two aspects are contradictory, and how to achieve a balance is a problem worth considering.

[0004] In terms of manufacturing processes, on the one hand, during the microbridge manufacturing process, there is a significant amount of time spent exposed to air between different processes. On the other hand, many mature MEMS etching processes, especially dry etching, can over-etch the underlying thin film material, increasing the non-uniformity of the sensitive layer and thus worsening the uniformity of the sensitive cells. Therefore, it is necessary to improve the structure and processes to enhance the protection of the sensitive layer during manufacturing.

[0005] As cell sizes decrease, cell linewidths also gradually shrink. However, the dimensional errors of each process layer and the alignment deviations between processes are limited by the precision of the equipment.

[0006] Therefore, how to manufacture structures with smaller linewidths has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] In view of the above-mentioned deficiencies of the prior art, the present invention provides a microbridge unit for microradiometric heat measurement, its array structure and manufacturing method, the purpose of which is to balance the stability of the microbridge support and the rational layout of the sensitive layer, improve the influence of unstable factors in conventional processes on the performance of the microbridge, and solve the influence of process deviations of small linewidth patterns at different levels.

[0008] To achieve the above objectives, the present invention discloses a microbridge unit for microthermometry, comprising a bridge surface, bridge piers, and bridge arms disposed on a rectangular substrate.

[0009] The four bridge piers are arranged in pairs, each pair, close to two opposite edges of the substrate. The spacing between the two bridge piers in each pair is controlled along the length of the corresponding edge to be the minimum value allowed by the manufacturing process.

[0010] The bridge deck is located between the two sets of piers;

[0011] The center of the bridge surface coincides with the center of the substrate;

[0012] The two sets of piers are connected to the bridge deck by two sets of bridge arms arranged symmetrically with respect to the center of the substrate.

[0013] Each set of bridge arms includes a first bridge arm and a second bridge arm;

[0014] Each of the first bridge arms includes a concave structure;

[0015] The two concave structures of the two first bridge arms are symmetrically arranged on the outer side of the bridge surface with respect to the center of the substrate, forming a rectangle with the bridge surface having a notch near each of the second bridge arms;

[0016] Both second bridge arms include irregular structures that match the shape of the notch, and the irregular structures and the two concave structures of the two first bridge arms form a rectangular frame around the bridge deck.

[0017] Each of the aforementioned "concave" structures is connected to the corresponding bridge pier via at least one first "H" shaped structure;

[0018] Each of the first "H"-shaped structures is disposed between the corresponding edge of the "concave"-shaped structure and the corresponding position of the substrate;

[0019] Each of the irregular structures is connected to the corresponding pier by at least one second "H"-shaped structure;

[0020] Each of the two long sides of the second "H" shaped structure is arranged along the two long sides of the first "H" shaped structure of the other set of bridge arms, and is spaced apart from the first "H" shaped structure of the other set of bridge arms.

[0021] Each of the second bridge arm and the pier connected thereto has only a supporting function for the bridge deck;

[0022] Each of the first bridge arms and the piers connected thereto serve both as supports and as electrical connections to the bridge deck.

[0023] Preferably, the maximum spacing between the two bridge piers in each group does not exceed the width of the substrate - the width of the bridge pier × 2 - the width of the first bridge arm - the width of the second bridge arm - the minimum process capability × 2.

[0024] Preferably, the distance between each of the first bridge arms or each of the second bridge arms and the edge of the substrate at the corresponding position is no greater than the minimum process capability value ÷ 2.

[0025] Preferably, the bridge deck comprises multiple membrane layers;

[0026] The multiple membrane layers, from bottom to top, include a lower support layer, a sensitive layer, a middle protective layer, a middle support layer, an electrode layer, and an upper support layer, and the remaining layers of the membrane layers are different in different regions of the bridge surface;

[0027] The supporting and electrical connection parts of each bridge arm are arranged from bottom to top as a lower support layer, a middle support layer, an electrode layer, and an upper support layer; the supporting parts are arranged from bottom to top as a lower support layer, a middle support layer, and an upper support layer.

[0028] More preferably, the lower support layer, the middle protective layer, the middle support layer, and the upper support layer are all made of the same or different insulating materials.

[0029] An array structure of microbridge units for micro-radiative heat measurement, including the microbridge units for micro-radiative heat measurement;

[0030] Multiple microbridge units for micromeasuring radiative heat are arranged in a rectangular array, comprising multiple rows and columns;

[0031] In the plurality of microbridge units for microthermometry arranged in a straight line along the length of each substrate, every two adjacent microbridge units for microthermometry share two bridge piers close to the short side of the corresponding substrate.

[0032] Preferably, the electrical connections between the microbridge units for micromeasuring radiative heat that share two piers are independent of each other;

[0033] In this case, one of the bridge piers serves both as a support and an electrical connection for one of the microbridge units used for micro-radiative heat measurement, and only as a support for the other microbridge unit used for micro-radiative heat measurement.

[0034] The other pier serves only as a support for one of the microbridge units for micro-radiative heat measurement, and also serves as an electrical connection and support for the other microbridge unit for micro-radiative heat measurement.

[0035] The minimum value of the bridge arm spacing of the microbridge unit for micro-radiative heat measurement, which shares two piers, is the "minimum process capability".

[0036] The present invention also provides a manufacturing method for manufacturing the microbridge unit for microthermometry, or an array structure of the microbridge unit for microthermometry, comprising the following steps:

[0037] Step 1: On a substrate on which a sacrificial layer has been prepared and a support aperture window has been etched in the sacrificial layer, a support layer, a sensitive layer, and a middle protective layer are sequentially deposited in different chambers of the same device.

[0038] Step 2: Photolithography and etching of the middle protective layer and the sensitive layer, etching away the areas corresponding to the edges of the bridge deck and the bridge arm, stopping at the lower support layer to form the sensitive area;

[0039] Step 3: Deposit a support layer to cover the sensitive area;

[0040] Step 4: Form contact holes at the bottom of the support hole window and form contact windows on the surface of the sensitive layer by photolithography and etching in two stages;

[0041] The contact hole is etched onto the surface of the readout circuit connection port;

[0042] The contact window is etched onto the surface of the sensitive layer;

[0043] Step 5: Deposit an electrode layer and a supporting metal layer to form an electrical connection in the contact hole and the contact window;

[0044] Step 6: Photolithography and etching of the supporting metal layer to form bridge piers, and photolithography and etching to the electrode layer;

[0045] Step 7: Photolithography and etching of the electrode layer corresponding to the bridge surface area, photolithography and etching to the middle support layer, so that the electrode layer in the sensitive layer area is directly disconnected;

[0046] At the same time, the bridge arm that only serves as a support and is connected to the bridge deck is partially etched away in the electrode layer, thereby disconnecting the electrical connection between the bridge pier that only serves as a support and the bridge deck.

[0047] Step 8: Deposit the upper support layer to form a surface protection and balance the prestress;

[0048] Step 9: Photolithography and etching of the bridge arm region down to the surface of the sacrificial layer, including etching the upper support layer, electrode layer, middle support layer and lower support layer;

[0049] Step 10: Release and remove the sacrificial layer to form a microbridge structure.

[0050] Preferably, after the sensitive layer is deposited, the intermediate protective layer is deposited in different vacuum chambers of the same device to prevent the sensitive layer from being affected by air; after the intermediate protective layer and the sensitive layer are etched to form the sensitive area, the surface of the sensitive layer is still protected by the intermediate protective layer, with only the sidewalls exposed. Then, an intermediate support layer is deposited to cover the exposed sidewalls of the sensitive layer, and then the contact window is etched to connect with the subsequently deposited electrode.

[0051] The first etching disconnects the direct connection between the two ends of the electrode of each microbridge unit used for microthermometry in the sensitive layer region. At the same time, it disconnects the electrical connection between the supporting pier and the corresponding microbridge unit. The etching pattern is a large linewidth pattern.

[0052] The second etching is performed after the deposition of the upper support layer, and the etched pattern is a small linewidth pattern.

[0053] The small linewidth patterns of the upper support layer and the electrode layer in the corresponding region of the bridge arm are etched under the same photolithographic mask.

[0054] The beneficial effects of this invention are:

[0055] The application of this invention can take into account both the stability of microbridge support and the reasonable layout of sensitive layers, improve the impact of unstable factors in conventional processes on microbridge performance, and solve the impact of process deviations in small linewidth patterns at different levels.

[0056] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0057] Figure 1 The diagram shows a schematic of the structure of a microbridge unit for micromeasuring radiative heat in one embodiment of the present invention.

[0058] Figure 2 This invention illustrates the following: Figure 1 Schematic diagram of the cross-sectional structure along the AA direction.

[0059] Figure 3 This diagram illustrates a microbridge array structure for microthermometry in one embodiment of the present invention.

[0060] Figure 4 This diagram illustrates a step 1 of an embodiment of the present invention, in which a support hole window is etched in the sacrificial layer.

[0061] Figure 5 This diagram illustrates the deposition of the lower support layer, sensitive layer, and middle protective layer in step 1 of an embodiment of the present invention.

[0062] Figure 6 This diagram illustrates the completion of step 2 according to an embodiment of the present invention.

[0063] Figure 7 This diagram illustrates the completion of step 3 according to an embodiment of the present invention.

[0064] Figure 8 This diagram illustrates the completion of step 4 according to an embodiment of the present invention.

[0065] Figure 9 This diagram illustrates the completion of step 5 according to an embodiment of the present invention.

[0066] Figure 10 This diagram illustrates the completion of step 6 according to an embodiment of the present invention.

[0067] Figure 11 This diagram illustrates the completion of step 7 according to an embodiment of the present invention.

[0068] Figure 12 This diagram illustrates the completion of step 8 according to an embodiment of the present invention.

[0069] Figure 13 This diagram illustrates the completion of step 9 according to an embodiment of the present invention.

[0070] Figure 14 This diagram illustrates the completion of step 10 according to an embodiment of the present invention.

[0071] Figure 15 A schematic diagram of the structure of a microbridge unit used in the prior art for microthermometry is shown.

[0072] Figure 16 This diagram illustrates the completion of the first etching of the electrode layer in one embodiment of the present invention.

[0073] Figure 17 This diagram illustrates a schematic of a support layer being deposited on the electrode layer before a second etching, according to an embodiment of the present invention.

[0074] Figure 18 This diagram illustrates the second etching of the electrode layer in one embodiment of the present invention.

[0075] Figure 19 The diagram shows a deformation simulation of two existing bridge pier structures.

[0076] Figure 20 The diagram shows the deformation curves of two existing bridge pier structures.

[0077] Figure 21 A variation simulation diagram of an embodiment of the present invention is shown.

[0078] Figure 22 A variation curve diagram of an embodiment of the present invention is shown.

[0079] Figure 23 The simulation results of the electric field distribution of two existing bridge pier structures are shown.

[0080] Figure 24 The simulation results of the electric field distribution according to an embodiment of the present invention are shown.

[0081] Figure 25 A schematic diagram of the structure of a microbridge unit for micromeasuring radiative heat is shown in a second embodiment of the present invention.

[0082] Figure 26 This diagram illustrates the structure of a microbridge unit for micromeasuring radiative heat in a third embodiment of the present invention.

[0083] Figure 27 This diagram illustrates the structure of a microbridge unit for micromeasuring radiative heat in a fourth embodiment of the present invention. Detailed Implementation

[0084] Example

[0085] like Figure 1 and Figure 2 As shown, the microbridge unit for micromeasuring radiative heat includes a bridge surface 1, a pier 2, and a bridge arm 3 disposed on a rectangular substrate 9.

[0086] Among them, the four bridge piers 2 are arranged in pairs close to the two opposite edges of the substrate 9, and the spacing between the two bridge piers 2 in each group is controlled along the length direction of the corresponding edge to the minimum value allowed by the manufacturing process.

[0087] A bridge deck 1 is located between the two sets of piers 2;

[0088] The center of bridge surface 1 coincides with the center of substrate 9;

[0089] Two sets of piers 2 are connected to the bridge deck 1 by two sets of bridge arms 3 arranged symmetrically according to the center of the substrate 9;

[0090] Each set of bridge arms 3 includes a first bridge arm 31 and a second bridge arm 32;

[0091] Each of the first bridge arms 31 includes a concave structure;

[0092] The two concave structures of the two first bridge arms 31 are arranged symmetrically on the outside of the bridge surface 1 according to the center of the substrate 9, forming a rectangle with the bridge surface 1 with a notch near each second bridge arm 32.

[0093] Both second bridge arms 32 include irregular structures that match the shape of the notch, and together with the two "concave" structures of the two first bridge arms 31, they form a rectangular frame around the bridge deck 1.

[0094] Each concave structure is connected to the corresponding pier via at least one first H-shaped structure.

[0095] Each first "H" shaped structure is disposed between the corresponding edge of the "concave" shaped structure and the corresponding position of the substrate 9;

[0096] Each irregular structure is connected to the corresponding pier by at least one second "H" shaped structure.

[0097] The two long sides of each second "H" shaped structure are arranged along the two long sides of the first "H" shaped structure of another set of bridge arms 3, and are spaced apart from the first "H" shaped structure of the other set of bridge arms 3.

[0098] Each second bridge arm 32 and the pier 2 connected to it only have a supporting function for the bridge deck 1;

[0099] Each first bridge arm 31 and the pier 2 connected to it serve both as a support and an electrical connection for the bridge deck 1.

[0100] In some embodiments, the maximum spacing between the two bridge piers 2 in each group does not exceed the width of the substrate 9 - the width of the bridge pier 2 × 2 - the width of the first bridge arm 31 - the width of the second bridge arm 32 - the minimum process capability × 2.

[0101] In some embodiments, the distance between each first bridge arm 31 or each second bridge arm 32 and the edge of the corresponding position of the substrate 9 is no greater than the minimum process capability value ÷ 2.

[0102] In some embodiments, the bridge deck 1 includes multiple membrane layers;

[0103] The multiple film layers, from bottom to top, include a lower support layer 5, a sensitive layer 6, a middle protective layer 7, a middle support layer 8, an electrode layer 10, and an upper support layer 12, and the remaining layers of the film layers in different regions of the bridge surface 1 are different.

[0104] The parts of each bridge arm 3 that have support and electrical connection functions are, from bottom to top, the lower support layer 5, the middle support layer 8, the electrode layer 10, and the upper support layer 12; the parts that only have support functions are, from bottom to top, the lower support layer 5, the middle support layer 8, and the upper support layer 12.

[0105] like Figure 1 and Figures 25 to 27 As shown, the present invention enhances the support strength and toughness of the bridge deck 1, and the deformation of each membrane layer combination is smaller over a larger range, with a larger margin for size and membrane thickness design.

[0106] Moreover, the coverage area of ​​the sensitive layer 6 has not been reduced, the connection layout between the electrode layer 10 and the sensitive layer 6 is more reasonable, the electric field distribution is more uniform, and the functional area of ​​the sensitive layer 6 is fully utilized.

[0107] In some embodiments, the lower support layer 5, the middle protective layer 7, the middle support layer 8, and the upper support layer 12 are all made of the same or different insulating materials.

[0108] like Figure 3 As shown, the present invention provides an array structure of microbridge units for microthermometry, comprising a plurality of microbridge units for microthermometry as described in any one of claims 1 to 3.

[0109] Multiple microbridge units for micro-radiative heat measurement are arranged in a rectangular array, including multiple rows and columns;

[0110] In a plurality of microbridge units for micro-radiative heat measurement arranged in a straight line along the length of each substrate 9, every two adjacent microbridge units for micro-radiative heat measurement share two bridge piers 2 close to the short side of the corresponding substrate 9.

[0111] In some embodiments, the electrical connections between every two microbridge units sharing two piers 2 for micro-radiative heat measurement are independent of each other;

[0112] Among them, one pier 2 serves as both support and electrical connection for one microbridge unit used for micro-radiative heat measurement, and only serves as support for another microbridge unit used for micro-radiative heat measurement.

[0113] The other pier 2 serves only as a support for one microbridge unit used for micro-radiative heat measurement, and also serves as an electrical connection and support for another microbridge unit used for micro-radiative heat measurement.

[0114] The minimum value of the bridge arm spacing 3 of the microbridge unit used for micro-radiative heat measurement, which shares two piers 2, is the "minimum process capability".

[0115] Each of the electrical connection ports is connected to the corresponding port of the readout circuit of the substrate.

[0116] like Figures 4 to 14 As shown, the present invention also provides a manufacturing method for manufacturing microbridge units for microthermometry, or for manufacturing an array structure of microbridge units for microthermometry, comprising the following steps:

[0117] like Figure 4 and Figure 5 As shown, in step 1, on the substrate 9 on which the sacrificial layer 4 has been prepared and the support hole window 41 has been etched, the support layer 5, the sensitive layer 6 and the middle protective layer 7 are sequentially deposited in different chambers of the same device.

[0118] Depositing the support layer 5, the sensitive layer 6, and the intermediate protective layer 7 sequentially in different chambers of the same device can reduce the exposure time of the sensitive layer 6 to air.

[0119] like Figure 6As shown, in step 2, the middle protective layer 7 and the sensitive layer 6 are photolithographically etched and etched to remove the area corresponding to the edge of the bridge surface 1 and the area of ​​the bridge arm 3, stopping at the lower support layer 5 to form the sensitive area. The entire surface of the sensitive layer 6 is protected by the middle protective layer 7, with only the sidewalls exposed.

[0120] like Figure 7 As shown, in step 3, the support layer 8 is deposited to cover the sensitive area and form a protective sidewall for the sensitive layer;

[0121] like Figure 8 As shown, in step 4, a contact hole 42 is formed at the bottom of the support hole window 41 by photolithography and etching in two steps, and a contact window 61 is formed on the surface of the sensitive layer 6.

[0122] Contact hole 42 is etched onto the surface of the readout circuit connection port;

[0123] Contact window 61 is etched onto the surface of sensitive layer 6;

[0124] Since the required etching film layers and etching depths for contact holes 42 and contact windows 61 are different, photolithography and etching need to be performed in two separate steps.

[0125] like Figure 9 As shown, in step 5, the electrode layer 10 and the supporting metal layer 11 are deposited to form an electrical connection in the contact hole 42 and the contact window 61.

[0126] like Figure 10 As shown, step 6: photolithography and etching of the supporting metal layer 11 to form the bridge pier 2, and photolithography and etching to the electrode layer 10;

[0127] To reduce the etching of the underlying electrode layer 10 due to over-etching and to ensure electrode uniformity, wet etching is used.

[0128] When designing, a lateral etching allowance should be reserved to compensate for the loss of the actual size of pier 2 caused by lateral etching. That is, the design size of pier 2 = the actual size of pier 2 + the amount of lateral etching in the process × 2.

[0129] When the metal of the pier 2 is etched, the lateral etching will only affect the root of the bridge arm 3, and the design can be compensated according to the amount of lateral etching in the process.

[0130] like Figure 11 Step 7: Photolithography and etching of the area corresponding to the bridge surface 1 of the electrode layer 10, photolithography and etching to the middle support layer 8, so that the electrode layer 10 in the sensitive layer 6 area is directly disconnected.

[0131] At the same time, the bridge arm 3, which only serves as a support and connects to the bridge deck 1, is partially etched away in the electrode layer 10, thereby disconnecting the electrical connection between the bridge pier 2, which only serves as a support, and the bridge deck 1.

[0132] like Figure 12 Step 8: Deposit the upper support layer 12 to form a surface protection and balance the prestress;

[0133] like Figure 13 Step 9: Photolithography and etching of the bridge arm 3 region up to the surface of the sacrificial layer 4, including etching of the upper support layer 12, electrode layer 10, middle support layer 8 and lower support layer 5;

[0134] like Figure 14 Step 10: Release and remove sacrificial layer 4 to form a microbridge structure.

[0135] This invention improves the impact of unstable factors in conventional processes on the performance of microbridges and solves the problem of process alignment deviations in small linewidth patterns at different levels.

[0136] Except for the sensitive layer 6 and the selected film layer, which are made of special materials and processes, all other materials and processes in this invention are conventional. Conventional photolithography, deposition, etching, cleaning and other process modules can be combined into a complete process flow according to the steps of this invention, which is more conducive to manufacturing process implementation and facilitates mass production.

[0137] In some embodiments, after the sensitive layer 6 is deposited, a protective layer 7 is deposited in a different vacuum chamber of the same device to protect the sensitive layer 6 from air. After the protective layer 7 and the sensitive layer 6 are etched to form the sensitive area, the surface of the sensitive layer 6 is still protected by the protective layer 7, with only the sidewalls exposed. Then, a support layer 8 is deposited to cover the exposed sidewalls of the sensitive layer 6, and the contact window 61 is etched to connect with the subsequently deposited electrode.

[0138] In practical applications, under the protection of the middle protective layer 7 and the middle support layer 8, the sensitive layer 6 will not be affected by over-etching when the electrode is etched, thus ensuring the uniformity of the functional area of ​​the sensitive layer 6.

[0139] like Figures 16 to 18 As shown, in some embodiments, the electrode layer is etched in two steps;

[0140] The first etching disconnects the direct connection between the two ends of the electrode of each microbridge unit used for micro-thermometry in the sensitive layer 6 region. At the same time, it disconnects the electrical connection between the supporting piers and the corresponding microbridge units. The etching pattern is a large linewidth pattern.

[0141] Cross-sectional view after etching is shown below Figure 5 The top view after etching in the embodiment is as follows: Figure 16 .

[0142] The second etching was performed after the deposition of the support layer 12, and the etched pattern was a small linewidth pattern.

[0143] Cross-sectional view after etching is shown below Figure 13The top view after etching in the embodiment is as follows: Figure 18 .

[0144] The small linewidth patterns of the upper support layer 12 and the electrode layer 10 in the corresponding area of ​​the bridge arm 3 are etched under the same photolithography mask.

[0145] In practical applications, by achieving zero deviation between film layers in a small linewidth pattern area without increasing the number of photolithography processes, the alignment accuracy requirements of the process equipment are reduced.

[0146] like Figures 1 to 24 As shown, each microbridge unit for micro-radiative heat measurement in this invention is supported by four piers 2. The bridge deck 1 is laid out in an approximately rectangular shape. The piers 2 are located on both sides of the bridge deck 1, and the slender and curved bridge arms 3 are located on the other two sides of the bridge deck 1. Adjacent microbridge units for micro-radiative heat measurement share two piers 2.

[0147] like Figures 19 to 24 As shown, a parametric simulation model was established. Simulation analysis shows that the present invention enhances the support strength and toughness of bridge deck 1, and the deformation of each membrane layer combination is smaller over a wider range. For example, Figure 15 The existing technology and the simulation results of the prestressed deformation of the microbridge unit for microthermal radiation of the present invention have a larger design margin in terms of size and film thickness. The existing technology used for comparison is a similar structural layout and a two-pier support structure of the same size, but the deformation is significantly increased.

[0148] Furthermore, the coverage area of ​​the sensitive layer 6 has not been reduced, the connection layout between the electrode layer 10 and the sensitive layer 2 is more reasonable, and the electric field distribution is more uniform. See details below. Figure 15 The existing technology and the electric field distribution simulation results of this invention enable the full utilization of the functional region of the sensitive layer 6.

[0149] like Figure 15 As shown, in the prior art, the pier 2 is located at the corner of the bridge deck 1. In order to increase the area of ​​the absorption layer, the shape of the bridge deck 1 is generally not rectangular, resulting in poor uniformity of electric field distribution. Outside the rectangular area, a larger area does not fully utilize the function of the sensitive layer.

[0150] The connection position between the bridge arm 3 and the pier 2 in this invention is located in the area near the middle of the pier 2. When the metal of the pier 2 is etched, the lateral etching will only affect the root of the bridge arm 3, and the design can be compensated according to the amount of lateral etching in the process.

[0151] like Figure 15 In the existing technology, the bridge arm 3 is connected to the edge of the pier 2. When the pier 2 is etched, the affected area of ​​the bridge arm 3 is the entire edge of the pier.

[0152] After the sensitive layer 6 is deposited, a protective layer is then deposited in a different vacuum chamber of the same equipment, so that the surface of the sensitive layer 6 is not affected by air after the process is completed.

[0153] After the sensitive area is formed, the present invention deposits a support layer 8 to cover the sidewall of the exposed sensitive layer 6, and then etches the contact window 42 to connect with the subsequently deposited electrode.

[0154] Under the protection of the middle protective layer 7 and the middle support layer 8, over-etching will not affect the sensitive layer of the functional area during electrode etching, thus ensuring the uniformity of the functional area of ​​the sensitive layer.

[0155] In the past, existing structures lacked a protective layer, and the sensitive layer 6 was exposed to air for a long time. During the etching of the electrode, over-etching caused uneven etching of the sensitive layer surface, resulting in poor performance uniformity and stability between different batches.

[0156] The electrode layer 10 of this invention is etched in two stages. The first etching disconnects the direct connection between the two ends of the microbridge unit electrode in the sensitive layer 6 region, and simultaneously disconnects the electrical connection between the supporting pier 2 and the corresponding microbridge unit. The etched pattern is a large linewidth pattern. The second etching is performed after the deposition of the support layer 12, resulting in a small linewidth pattern. This allows the support layer 12 and the small linewidth pattern of the electrode layer 10 in the bridge arm 3 region to be etched under the same photolithographic mask. Without increasing the number of photolithography processes, zero deviation between the film layers in the small linewidth pattern region is achieved, thereby reducing the alignment accuracy requirements of the process equipment.

[0157] In the past, with existing structural and process designs, the electrode layer 10 was etched in one go to form a small linewidth pattern in the bridge arm 3 region, and then the support layer was etched to form the small linewidth bridge arm 3. The photolithography of the two small linewidth patterns significantly increased the alignment accuracy requirements of the equipment and could not achieve zero alignment deviation.

[0158] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A microbridge unit for micromeasuring radiative heat, comprising a bridge surface (1), bridge piers (2), and bridge arms (3) disposed on a rectangular substrate (9); characterized in that, The four bridge piers (2) are arranged in pairs near the two opposite edges of the substrate (9), and the spacing between the two bridge piers (2) in each group is controlled along the length direction of the corresponding edge to be the minimum value allowed by the manufacturing process. The bridge deck (1) is provided between the two sets of piers (2); The center of the bridge surface (1) coincides with the center of the substrate (9); The two sets of piers (2) are connected to the bridge deck (1) by two sets of bridge arms (3) arranged symmetrically according to the center of the substrate (9); Each of the bridge arms (3) includes a first bridge arm (31) and a second bridge arm (32); Each of the first bridge arms (31) includes a concave structure; The two concave structures of the two first bridge arms (31) are arranged symmetrically with respect to the center of the substrate (9) on the outside of the bridge surface (1), forming a rectangle with the bridge surface (1) with a notch near each of the second bridge arms (32); Both second bridge arms (32) include irregular structures that match the shape of the notch, and the irregular structures and the two concave structures of the two first bridge arms (31) form a rectangular frame around the bridge deck (1); Each of the concave structures is connected to the corresponding pier via at least one first H-shaped structure; Each of the first "H" shaped structures is disposed between the corresponding edge of the "concave" shaped structure and the corresponding position of the substrate (9); Each of the irregular structures is connected to the corresponding pier via at least one second "H"-shaped structure; Each of the two long sides of the second "H" shaped structure is arranged along the two long sides of the first "H" shaped structure of the other set of bridge arms (3), and is spaced apart from the first "H" shaped structure of the other set of bridge arms (3); Each of the second bridge arm (32) and the pier (2) connected thereto has only a supporting function for the bridge deck (1); Each of the first bridge arm (31) and the pier (2) connected thereto serves both as a support and an electrical connection for the bridge deck (1).

2. The microbridge unit for micromeasuring radiative heat according to claim 1, characterized in that, The maximum spacing between the two bridge piers (2) in each group shall not exceed the width of the substrate (9) - the width of the bridge pier (2) × 2 - the width of the first bridge arm (31) - the width of the second bridge arm (32) - the minimum process capability × 2.

3. The microbridge unit for micromeasuring radiative heat according to claim 1, characterized in that, The distance between each of the first bridge arm (31) or each of the second bridge arm (32) and the edge of the corresponding position of the substrate (9) is no greater than the minimum process capability value ÷ 2.

4. The microbridge unit for micromeasuring radiative heat according to claim 1, characterized in that, The bridge deck (1) comprises multiple membrane layers; The multiple membrane layers, from bottom to top, include a lower support layer (5), a sensitive layer (6), a middle protective layer (7), a middle support layer (8), an electrode layer (10), and an upper support layer (12), and the remaining layers of the membrane layers in different regions of the bridge surface (1) are different; The parts of each bridge arm (3) that have support and electrical connection functions are, from bottom to top, a lower support layer (5), a middle support layer (8), an electrode layer (10), and an upper support layer (12), while the parts that only have support functions are, from bottom to top, a lower support layer (5), a middle support layer (8), and an upper support layer (12).

5. The microbridge unit for micromeasuring radiative heat according to claim 4, characterized in that, The lower support layer (5), the middle protective layer (7), the middle support layer (8), and the upper support layer (12) are all made of the same or different insulating materials.

6. An array structure of microbridge units for micrometric radiation heat measurement, characterized in that, Includes multiple microbridge units for micromeasuring radiative heat as described in any one of claims 1 to 5; Multiple microbridge units for micromeasuring radiative heat are arranged in a rectangular array, comprising multiple rows and columns; In the multiple microbridge units for microthermometry arranged in a straight line along the length of each substrate (9), every two adjacent microbridge units for microthermometry share two bridge piers (2) close to the short side of the corresponding substrate (9).

7. The array structure of microbridge units for microthermometry according to claim 6, characterized in that, The electrical connections between the microbridge units for micro-radiative heat measurement that share two piers (2) are independent of each other; One of the bridge piers (2) serves both as a support and an electrical connection for one of the microbridge units for micro-measurement of radiant heat, and only as a support for the other microbridge unit for micro-measurement of radiant heat. The other pier (2) has only a supporting function for one of the microbridge units for micro-radiative heat measurement, and has both electrical connection and supporting functions for the other microbridge unit for micro-radiative heat measurement. The minimum value of the bridge arm (3) spacing of the microbridge unit for micro-radiative heat measurement shared by two bridge piers (2) is the "minimum process capacity".

8. A manufacturing method, characterized in that, For manufacturing a microbridge unit for micromeasuring radiative heat as described in any one of claims 1 to 5, or for manufacturing an array structure of microbridge units for micromeasuring radiative heat as described in claim 6 or 7, the following steps are included: Step 1: On a substrate (9) on which a sacrificial layer (4) has been prepared and a support hole window (41) has been etched in the sacrificial layer (4), a support layer (5), a sensitive layer (6) and a middle protective layer (7) are sequentially deposited in different chambers of the same device. Step 2: Photolithography and etching of the middle protective layer (7) and the sensitive layer (6) to remove the area corresponding to the edge of the bridge deck (1) and the area of ​​the bridge arm (3), stopping at the lower support layer (5) to form the sensitive area; Step 3: Deposit the support layer (8) to cover the sensitive area; Step 4: Form a contact hole (42) at the bottom of the support hole window (41) by photolithography and etching in two steps, and form a contact window (61) on the surface of the sensitive layer (6); The contact hole (42) is etched onto the surface of the readout circuit connection port; The contact window (61) is etched onto the surface of the sensitive layer (6); Step 5: Deposit an electrode layer (10) and a supporting metal layer (11) to form an electrical connection in the contact hole (42) and the contact window (61); Step 6: Photolithography and etching of the supporting metal layer (11) to form the bridge pier (2), and photolithography and etching to the electrode layer (10); Step 7: Photolithography and etching of the electrode layer (10) corresponding to the bridge surface (1) area, photolithography and etching to the middle support layer (8) to disconnect the direct connection of the sensitive layer (6) area; At the same time, the bridge arm (3) that only serves as a support and is connected to the bridge deck (1) is partially etched away in the electrode layer (10), so that the electrical connection between the bridge pier (2) that only serves as a support and the bridge deck (1) is broken. Step 8: Deposit the upper support layer (12) to form a surface protection and balance the prestress; Step 9: Photolithography and etching of the bridge arm (3) region down to the surface of the sacrificial layer (4), including etching of the upper support layer (12), electrode layer (10), middle support layer (8) and lower support layer (5); Step 10: Release and remove the sacrificial layer (4) to form a microbridge structure.

9. The manufacturing method according to claim 8, characterized in that, After the sensitive layer (6) is deposited, the intermediate protective layer (7) is deposited in different vacuum chambers of the same device to protect the sensitive layer (6) from air. After etching the intermediate protective layer (7) and the sensitive layer (6) to form the sensitive area, the surface of the sensitive layer (6) is still protected by the intermediate protective layer (7), with only the sidewalls exposed. Then, the intermediate support layer (8) is deposited to cover the exposed sidewalls of the sensitive layer (6), and the contact window (61) is etched to connect with the subsequently deposited electrode.

10. The manufacturing method according to claim 8, characterized in that, The electrode layer (10) is etched in two stages; The first etching disconnects the direct connection between the two ends of the electrode of each microbridge unit used for micro-radiative heat measurement in the sensitive layer (6) region, and at the same time disconnects the electrical connection between the supporting pier and the corresponding microbridge unit. The etching pattern is a large linewidth pattern. The second etching is performed after the deposition of the upper support layer (12), and the etching pattern is a small linewidth pattern. The small linewidth patterns of the upper support layer (12) and the electrode layer (10) in the corresponding area of ​​the bridge arm (3) are etched under the same photolithography mask.

Images