CN106611806A - Infrared detector structure and preparation method thereof - Google Patents

Abstract

The purpose of the present invention is to provide an infrared detector structure and its preparation method. Specifically, an infrared detector structure includes: a substrate, a main bridge deck, and an adiabatic beam for supporting the main bridge deck above the substrate, so that the main bridge deck is separated from the substrate; It is used to connect the substrate and the heat-insulating beam; wherein, the end surface of the substrate facing the bridge surface of the main body has an infrared reflective film, and the bridge surface of the main body contains an electrode film pattern and a heat-sensitive film pattern, and the electrode film pattern includes a positive electrode composed of a comb-shaped pattern. Graphics and negative graphics, positive graphics and negative graphics are arranged in a staggered comb, forming a strip-shaped area that is bent back and forth between them. The strip-shaped area includes a heat-sensitive film area and a through-hole area, wherein the through-hole area is located in the strip-shaped area. The bending part divides the heat-sensitive film area into multiple independent rectangular areas. Compared with the prior art, the invention solves the inhomogeneous current and tip discharge defects caused by the interlaced arrangement of electrodes.

Description

A kind of infrared detector structure and preparation method thereof

technical field

The invention relates to the technical field of infrared detectors, in particular to the technology of an infrared detector structure and a preparation method thereof.

Background technique

The uncooled infrared detector has been widely used in the field of infrared thermal imaging. By absorbing infrared radiation, it causes the temperature change of the thermal sensitive film of the detector. The temperature change causes the resistance of the thermal sensitive film to change, and the change of resistance is converted into output through the readout circuit Signal.

A typical uncooled infrared detector includes a connecting post, an insulating beam, an infrared absorber, a readout electrode composed of an electrode film, and a thermistor composed of a part or all of the heat-sensitive film. The electrode film consists of two parts, positive and negative electrodes. One end of each part is electrically connected to the readout circuit in the substrate through a heat-insulating beam and a connecting post. At the same time, the heat-insulating beam and the connecting post also constitute the mechanical support of the heat-sensitive film; the electrode film The other end is connected to the heat sensitive film. The electrode film, heat-sensitive film and possible dielectric film between the insulating beams can be collectively referred to as the main bridge deck.

When the infrared detector is working, the readout circuit applies a bias voltage to the heat-sensitive film through the electrode film to form a current passing through the heat-sensitive material film. When the infrared detector receives infrared radiation, the electrode film absorbs the infrared radiation and conducts it to the heat-sensitive material film, causing the temperature change of the heat-sensitive film, thereby causing the resistivity of the heat-sensitive film to change, and the current passing through the heat-sensitive film also changes at the same time , the signal is output after being processed by the readout circuit.

The final performance of an infrared detector usually depends on several factors: 1) the thermal resistance of the insulating beam; 2) the absorption efficiency of the infrared absorbing film; 3) the electrical noise, including the noise of the readout circuit itself, and the thermal sensitivity of the detector. 1/f noise of the film; 4) time constant of the detector, which is determined by the thermal resistance of the insulating beam and the heat capacity of the film.

In the prior art, there are mainly two structural modes of the thermistor of the infrared detector and the electrode connected to the thermistor: one is a "sandwich" structure, that is, the electrode films serving as the positive and negative electrodes are respectively located on the thermal sensitive film. Up and down, the current passing through the heat-sensitive film is along the direction perpendicular to the film; the second type can be called coplanar electrodes, that is, the positive and negative electrode films are located on one plane, and the heat-sensitive film is located above or below the electrode plane , the current through the thermistor thin film resistor is along the direction parallel to the film. The above-mentioned first structure generally requires a relatively high thickness of the heat-sensitive film to achieve an absolute resistance value suitable for the readout circuit processing, and a thick heat-sensitive film will increase the heat capacity of the heat-insulating part between the detector and the substrate, that is, increase The time constant of the detector is rarely used in mature detectors at present. The second electrode structure is the current mainstream technology.

In specific applications, since the electrode film of the infrared detector is a conductor, it can be used as an infrared absorber at the same time, so as to avoid adding an additional infrared absorbing layer and lead to more complicated processing technology. By properly controlling the resistance of the electrode film and the spatial arrangement Therefore, the parameters that determine the efficiency of infrared absorption include the area of the electrode film and the pattern arrangement.

In the prior art, for example, US Pat. No. 5,912,464 discloses an infrared detector structure, and the electrodes in the structure are comb-shaped electrodes arranged in a staggered manner. As shown in Figure 1, the structure includes two connecting columns 1, two heat-insulating beams 2, an electrode film 3 and a heat-sensitive film 4, wherein the electrode film 3 is located on the heat-sensitive film 4, and the electrode film 3 forms a positive electrode and a heat-sensitive film 4. The negative electrode is located on a plane, W represents the width of the effective conductive part of the thermosensitive film, and L represents the length of the effective conductive part of the thermosensitive material. Here, the shaded part of the oblique line in Figure 1 is the positive pole or the negative pole, and the dashed line part is the negative pole or the negative pole. positive electrode. It can be seen from FIG. 1 that the shape of the heat-sensitive film 4 in this structure is bent back and forth. Since the shape of the effective conductor film (that is, the effective conductive part of the heat-sensitive film) is bent back and forth and contains two orthogonal directions (horizontal and vertical in the figure), the absorption of all polarization directions is limited. Advantageous (infrared radiation in nature is non-polarized radiation, that is, radiation that includes electric fields along all polarization directions). However, this staggered electrode structure has an inherent defect. In the bent part of the film conductor, the electrodes on both sides of the heat-sensitive film are not completely symmetrical and parallel, that is, the current at the bend is uneven. What's more serious is that the tip electrode is included in the bend, and there is a maximum value of current at the tip position, that is, there is a tip discharge phenomenon. Whether the current is uneven or the tip is discharged, additional electrical noise will be introduced. In addition, in the case where the detection units form a planar array, the tip structure makes the resistance value processing technology of the detection units very sensitive, which increases the inhomogeneity among the detection units in the array. The more times the effective resistance is bent, the greater the proportion of the bent part of the effective conductor film is, and the more noise is introduced.

Contents of the invention

One object of the present invention is to provide an infrared detector structure and its preparation method.

According to one aspect of the present invention, an infrared detector structure is provided, including: a substrate, a main body bridge deck, and:

thermal insulation beams, used to support the bridge deck of the main body suspended above the substrate, so that the bridge deck of the main body is separated from the substrate;

connecting posts for connecting the substrate and the insulating beams;

Wherein, the substrate has an infrared reflective film on the end face of the main body bridge, and the main body bridge includes electrode film patterns and heat-sensitive film patterns, and the electrode film patterns include positive electrodes composed of comb-shaped patterns. pattern and negative electrode pattern, the comb teeth of the positive electrode pattern and the negative electrode pattern are arranged alternately, and a strip-shaped area bent back and forth is formed between them, and the strip-shaped area includes a heat-sensitive film area and a through-hole area, wherein the through-hole The area is located at the bend of the strip-shaped area, and divides the heat-sensitive film area into a plurality of independent rectangular areas.

According to another aspect of the present invention, there is also provided a method for preparing the aforementioned infrared detector structure according to one aspect of the present invention, wherein the method includes the following steps:

- deposit infrared reflective film on the substrate;

- determine the position of the infrared reflective film and remove the infrared reflective film outside the position;

a coating a sacrificial layer material on the end surface of the substrate on which the infrared reflective film is deposited to form a sacrificial layer;

b forming grooves for connection posts of the infrared detector structure on the sacrificial layer;

c depositing a conductive metal film on the sacrificial layer and in the groove, and removing the conductive metal film outside the groove, so that the conductive metal film forms the connecting column;

d depositing an electrode film on the sacrificial layer;

- Determine the position of the electrode film pattern formed by the electrode film and remove the electrode film outside the position, wherein the electrode film pattern includes a positive electrode pattern and a negative electrode pattern respectively composed of comb-shaped patterns, the positive electrode The comb teeth of the graphic and the negative electrode graphic are arranged in a staggered manner, and a strip-shaped area bent back and forth is formed between them;

e depositing a heat-sensitive film on the end face of the sacrificial layer on which the electrode film pattern is formed;

f Determine the corresponding positions of the thermal insulation beam, the bridge deck of the main body and the through hole of the infrared detector structure, and remove the electrode film and the heat sensitive film outside the corresponding position to form the thermal insulation beam and the main body The bridge deck and the through hole, wherein the heat insulating beam is used to support the main body bridge deck to hang above the substrate, and is connected to the substrate through the connecting column, and the main body bridge deck includes the The electrode film pattern and the heat-sensitive film pattern formed by the heat-sensitive film, the through-hole area is located at the bend of the strip-shaped area, and the heat-sensitive film area is divided into a plurality of independent rectangular areas;

g removing the material of the sacrificial layer to obtain the infrared detector structure, wherein there is a gap between the bridge surface of the main body and the substrate.

According to yet another aspect of the present invention, there is also provided a method for preparing the aforementioned infrared detector structure according to one aspect of the present invention, wherein the method includes the following steps:

- deposit infrared reflective film on the substrate;

- determine the position of the infrared reflective film and remove the infrared reflective film outside the position;

A coating a sacrificial layer material on the end surface of the substrate deposited with the infrared reflective film to form a sacrificial layer;

B forming grooves for connecting columns of the infrared detector structure on the sacrificial layer;

C depositing a conductive metal film on the sacrificial layer and in the groove, and removing the conductive metal film other than the position of the groove, so that the conductive metal film forms the connecting column;

D depositing a heat-sensitive thin film on the sacrificial layer;

E depositing an electrode film on the heat-sensitive film;

- Determining the position of the electrode film pattern formed by the electrode film and removing the electrode film outside the position, and forming a heat-sensitive film area, wherein the electrode film pattern includes a positive electrode pattern composed of comb-shaped patterns respectively and the negative electrode pattern, the comb teeth of the positive electrode pattern and the negative electrode pattern are arranged alternately, and a strip-shaped area bent back and forth is formed between them;

F Determine the corresponding positions of the thermal insulation beam, the bridge deck of the main body and the through hole of the infrared detector structure, and remove the electrode film and the heat sensitive film outside the corresponding position to form the thermal insulation beam and the main body The bridge deck, the through hole and the heat-sensitive film pattern, wherein the heat-insulating beam is used to support the bridge deck of the main body suspended above the substrate, and is connected to the substrate through the connecting column, the The bridge surface of the main body includes the electrode film pattern and the heat-sensitive film pattern, and the through-hole area is located at the bend of the strip-shaped area, and divides the heat-sensitive film area into a plurality of independent rectangular areas;

G removing the material of the sacrificial layer to obtain the infrared detector structure, wherein there is a gap between the bridge surface of the main body and the substrate.

According to yet another aspect of the present invention, an uncooled infrared detector is also provided, wherein the uncooled infrared detector includes the aforementioned infrared detector structure according to one aspect of the present invention.

According to still another aspect of the present invention, an infrared imager is also provided, wherein the infrared imager includes the aforementioned infrared detector structure according to one aspect of the present invention.

According to yet another aspect of the present invention, a focal plane array is also provided, wherein the focal plane array includes the aforementioned infrared detector structure according to one aspect of the present invention.

Compared with the prior art, in the infrared detector structure of the present invention, the comb teeth of the positive electrode pattern and the negative electrode pattern constituting the electrode film pattern are arranged alternately, and a strip-shaped area bent back and forth is formed between them, and the strip-shaped area includes a thermosensitive The film area and the through-hole area, wherein the through-hole area is located at the bend of the strip-shaped area, divides the heat-sensitive film area into a plurality of independent rectangular areas, and solves the problem of the electrode staggered arrangement in the prior art The inherent uneven current and tip discharge problems also reduce the non-uniformity of the detector structure and electrical properties caused by film stress to a certain extent, making the detector noise optimal, simplifying the process flow, and reducing detection The time constant of the device structure.

Description of drawings

Other characteristics, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

Fig. 1 shows a kind of infrared detector structure in the prior art;

FIG. 2 shows a perspective view of an infrared detector structure according to an embodiment of the present invention;

Fig. 3 shows the structural top view of the infrared detector structure corresponding to the three-dimensional schematic diagram of the infrared detector structure shown in Fig. 2 and the cross-sectional view along the A-A section;

Fig. 4 shows a structural top view and a cross-sectional view along section A-A of an infrared detector structure according to another embodiment of the present invention.

The same or similar reference numerals in the drawings represent the same or similar components.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings.

Fig. 2 shows a three-dimensional schematic view of an infrared detector structure according to an embodiment of the present invention, and Fig. 3 shows a structural top view of an infrared detector structure corresponding to the three-dimensional schematic view of an infrared detector structure shown in Fig. 2 , wherein the infrared The detector structure includes: a substrate 5, a main body bridge deck, an infrared reflective film 7, and a thermal insulation beam 2, which is used to support the main body bridge deck and hang above the substrate 5, so that the main body bridge deck is in contact with the The substrate 5 is separated; the connecting column 1 is used to connect the substrate 5 and the heat insulating beam 2; wherein, the end surface of the substrate 5 facing the bridge surface of the main body has an infrared reflective film 7, and the main body The bridge deck includes an electrode film pattern 3 and a heat-sensitive film pattern 4. The electrode film pattern 3 includes a positive electrode pattern and a negative electrode pattern respectively composed of comb-shaped patterns. The comb teeth of the positive electrode pattern and the negative electrode pattern are arranged alternately. Form a strip-shaped area that is bent back and forth, and the strip-shaped area includes a heat-sensitive film area and a through-hole area 6, wherein the through-hole area is located at the bend of the strip-shaped area, and the heat-sensitive film area 4 divided into multiple independent rectangular areas.

Here, the heat-sensitive thin film can be made of materials such as amorphous silicon, amorphous silicon germanium, and vanadium oxide.

Here, the electrode film can absorb infrared radiation, and it can be made of titanium (Ti), titanium nitride (TiN), tantalum nitride (TaN) and other materials.

Here, the heat-insulating beam 2 is used for heat insulation and forming an electrical readout circuit, and is formed by laminating an electrode film and a heat-sensitive film, or only includes an electrode film. Preferably, the thermal insulation beam further includes a dielectric film. Here, the dielectric thin film may be formed of silicon oxide, silicon nitride and other materials.

Here, the substrate 5 is a silicon substrate or other semiconductor substrate including a readout circuit. Those skilled in the art should understand that the above-mentioned substrate 5 is only an example, and if other existing or future substrates 5 are applicable to the present invention, they should also be included in the protection scope of the present invention, and are incorporated by reference herein. here. In a specific embodiment, the readout circuit of the substrate 5 generates a readout current, and the current passes through the heat insulating beam 2 and the bridge surface of the main body, and the heat insulating beam 2 and the connecting post 1 together serve as a return channel of the readout circuit of the substrate 5 .

Here, the main body bridge deck is composed of an electrode film and a heat-sensitive film between the heat-insulating beams 2 , and its shape includes but not limited to various shapes such as rectangle and square. Preferably, the bridge deck of the main body further includes a dielectric film. Here, the dielectric thin film may be formed of silicon oxide, silicon nitride and other materials.

Here, the connecting column 1 can be connected to the substrate 5 and the heat insulating beam 2 by means of mechanical connection, welding and the like. In a specific embodiment, the connection post 1 can be made of conductive metal materials such as aluminum, copper, titanium and the like.

Preferably, the shape of the through hole area is a strip.

Preferably, the electrode film pattern 3 and the heat-sensitive film pattern 4 are stacked up and down and kept in electrical contact, and the electrode film forming the electrode film pattern 3 can be positioned below the heat-sensitive film forming the heat-sensitive film pattern 4 , can also be located above the heat-sensitive film.

Preferably, the comb-toothed pattern constituting the positive electrode pattern and the negative electrode pattern is a single-sided comb-toothed pattern and/or a double-sided comb-toothed pattern.

For ease of description, here, only taking the situation that the electrode film forming the electrode film pattern 3 is positioned above the thermosensitive film forming the thermosensitive film pattern 4 as an example, the structure of the infrared detector of the present invention is shown, as shown in FIG. 2/Figure 3/Figure 4.

Specifically, as shown in Figure 3, the comb-toothed figure that constitutes the positive electrode pattern and the negative electrode pattern is a single-sided comb-toothed pattern, and the shaded part of the oblique line in Figure 3 is the positive electrode pattern or the negative electrode pattern, while the dotted line Some of them are negative electrode patterns or positive electrode patterns accordingly, and the comb teeth of the positive electrode pattern and the negative electrode pattern are arranged alternately, forming a strip-shaped area bent back and forth between them, and the strip-shaped area includes a heat-sensitive film area and a through-hole area 6, wherein the The through-hole area 6 is located at the bend of the strip-shaped area, and divides the heat-sensitive film area into a plurality of independent rectangular areas. Here, the setting of the through hole area cuts off the electrode film into two parts, the positive and negative electrodes, which reduces the heat capacity of the infrared detector, which is beneficial to reduce the time constant and release the stress of the film; on the other hand, the through hole area will also The thermosensitive film between the positive and negative electrodes is divided into a plurality of regular rectangles, and the effective resistance of the infrared detector structure of the present invention formed by parallel connection, because the electrode films on both sides of these rectangular thermosensitive films are parallel to each other, the current is passed by the electrode film Uniformly passing through the thermosensitive film avoids tip discharge and uneven current; in addition, the above-mentioned distribution of the electrode film is conducive to absorbing infrared radiation; moreover, the infrared detector of the present invention is simple in structure and only includes the necessary thermistor film and resistance film layer, the process is simple and the cost is low.

Preferably, the present invention can also adjust the geometry of the effective part of the thermistor arbitrarily, so as to be suitable for thermosensitive materials with different resistivities. The distribution of the electrode film is favorable for absorbing infrared radiation.

In a preferred embodiment, the comb-toothed pattern that constitutes the positive electrode pattern and the negative electrode pattern is a mixed comb-toothed pattern composed of a single-sided comb-shaped pattern and a double-sided comb-shaped pattern, as shown in Figure 4 As shown, setting the through-hole region 6 at the same position based on the same principle realizes the optimization of the current distribution for the more complex interlaced electrode structure.

The present invention also includes a method flow for preparing the infrared detector structure shown in FIG. 2 . Specifically, at first, deposit an infrared reflective film on the substrate; then, determine the position of the infrared reflective film and remove the infrared reflective film outside the position; in step a, after the deposition of the substrate, Coating a sacrificial layer material on the end face of the infrared reflective film to form a sacrificial layer; in step b, forming a groove for the connecting column of the infrared detector structure on the sacrificial layer; in step c, Depositing a conductive metal film on the sacrificial layer and in the groove, and removing the conductive metal film other than the position of the groove, so that the conductive metal film forms the connecting column; in step d, Deposit an electrode film on the sacrificial layer; then, determine the position of the electrode film pattern formed by the electrode film and remove the electrode film other than the position, wherein the electrode film pattern includes a comb-shaped pattern respectively The positive electrode pattern and the negative electrode pattern formed, the comb teeth of the positive electrode pattern and the negative electrode pattern are arranged in a staggered manner, and a strip-shaped area bent back and forth is formed between them; in step e, the electrode film pattern is formed on the sacrificial layer Deposit a heat-sensitive thin film on the end face; in step f, determine the corresponding positions of the thermal insulation beam of the infrared detector structure, the bridge surface of the main body and the through hole, and remove the electrode film and the heat-sensitive film outside the corresponding position. film, to form the heat-insulating beam, the main body bridge deck and the through hole, wherein the heat-insulating beam is used to support the main body bridge deck to hang above the substrate, and pass through the connecting column and the connected to the substrate, the main body bridge includes the electrode film pattern and the heat-sensitive film pattern formed by the heat-sensitive film, the through-hole area is located at the bend of the strip-shaped area, and the heat-sensitive film The area is divided into a plurality of independent rectangular areas; in step g, the material of the sacrificial layer is removed to obtain the infrared detector structure, wherein there is a gap between the bridge surface of the main body and the substrate.

Specifically, firstly, an infrared reflective film is deposited on a substrate.

Then, determine the position of the infrared reflective film and remove the infrared reflective film outside the position. For example, using a graphics process method, first draw the position of the infrared reflective film 7 on the substrate 5 as shown in Figure 2; Reflective film layer.

In step a, a sacrificial layer material is coated on the end surface of the substrate on which the infrared reflective film is deposited to form a sacrificial layer. For example, following the above example, as shown in FIG. 2 , the end surface of the substrate 5 on which the infrared reflective film 7 is deposited is coated with a sacrificial layer material to form a sacrificial layer. Here, the material of the sacrificial layer includes, but is not limited to, polyimide (PI) (such as soluble PI), amorphous silicon (a-Si) and the like.

In step b, forming grooves for connecting pillars of the infrared detector structure on the sacrificial layer. For example, following the previous example, using a graphics process method, first draw the position of the connecting column on the substrate 5 as shown in Figure 2; then, remove the sacrificial layer at this position by photolithography, etching, etc. The groove required for the connecting column 1 of the infrared detector structure shown in 2.

In step c, a conductive metal film is deposited on the sacrificial layer and in the groove, and the conductive metal film other than the groove is removed, so that the conductive metal film forms the connecting column. For example, following the above example, a conductive metal film is deposited on the sacrificial layer and in the groove, and then the conductive metal film other than the position of the groove is removed by using a pattern process method, so that the conductive metal film A connecting column 1 as shown in FIG. 2 is formed. Here, the conductive metal thin film may be a thin film formed of conductive metal materials such as aluminum, copper, and titanium.

In step d, an electrode film is deposited on the sacrificial layer. Here, the electrode film can absorb infrared radiation, and it can be made of titanium (Ti), titanium nitride (TiN), tantalum nitride (TaN) and other materials.

Next, determine the position of the electrode film pattern formed by the electrode film and remove the electrode film outside the position, wherein the electrode film pattern includes a positive electrode pattern and a negative electrode pattern respectively composed of comb-shaped patterns, the The comb teeth of the positive electrode pattern and the negative electrode pattern are arranged alternately, and a strip-shaped area bent back and forth is formed between them. For example, using the graphics process method, first draw the electrode film pattern 3 as shown in Figure 2, at this time, the electrode film at the insulating beam 2 is reserved; then, remove the electrode film pattern 3 by photolithography, corrosion, etc. position and electrode film other than the position at insulation beam 2. At this time, the electrode film pattern 3 includes a positive electrode pattern and a negative electrode pattern respectively composed of comb-shaped patterns, and the comb teeth of the positive electrode pattern and the negative electrode pattern are arranged alternately, forming strip-shaped areas bent back and forth between them.

In step e, a heat-sensitive thin film is deposited on the end surface of the sacrificial layer on which the pattern of the electrode thin film is formed.

In step f, determine the corresponding positions of the thermal insulation beams of the infrared detector structure, the bridge deck of the main body, and the through holes, and remove the electrode film and the heat-sensitive film outside the corresponding positions to form the thermal insulation beams . The bridge deck of the main body and the through-hole area, wherein the heat-insulating beam is used to support the bridge deck of the main body to hang above the substrate, and is connected to the substrate through the connecting column, the The bridge surface of the main body includes the electrode film pattern and the heat-sensitive film pattern formed by the heat-sensitive film, and the through-hole area is located at the bend of the strip-shaped area, dividing the heat-sensitive film area into a plurality of independent rectangular area. For example, using a graphics process method, first draw the corresponding positions of the heat insulating beam, the main body bridge deck and the through hole as shown in Figure 2; then, remove the electrode film, The heat-sensitive film is used to form the heat-insulating beam 2, the main body bridge deck and the through-hole area 6 as shown in Figure 2, wherein the heat-insulating beam 2 is used to support the main body bridge deck to hang above the substrate 5, and connect The pillar 1 is connected to the substrate 5, the main body bridge includes the electrode film pattern and the heat-sensitive film pattern 4 formed by the heat-sensitive film, the through-hole area 6 is located at the bend of the strip-shaped area, and the The heat-sensitive film area is divided into multiple independent rectangular areas.

In step g, removing the sacrificial layer material to obtain the infrared detector structure, wherein there is a gap between the main bridge surface and the substrate, such as removing the sacrificial layer by oxygen plasma etching material, releasing the infrared detector structure to obtain the infrared detector structure as shown in FIG. 2 , wherein there is a gap between the bridge surface of the main body and the substrate 5 .

Preferably, in this method, before depositing the electrode film on the sacrificial layer, a first dielectric film can be deposited on the sacrificial layer; then, in step d, an electrode film is deposited on the first dielectric film; After depositing a heat-sensitive film on the end face of the layer formed with the electrode film pattern, deposit a second dielectric film on the heat-sensitive film; then, in step f, determine the thermal insulation beam and main body of the infrared detector structure The corresponding position of the bridge surface and the through hole, remove the first dielectric film, the electrode film, the heat sensitive film and the second dielectric film outside the corresponding position, so as to form the heat insulating beam, the The main body bridge deck and the through hole, wherein the heat insulating beam is used to support the main body bridge deck to hang above the substrate, and is connected to the substrate through the connecting column, and the main body bridge deck includes The electrode film pattern and the heat-sensitive film pattern formed by the heat-sensitive film, the through-hole area is located at the bend of the strip-shaped area, and divides the heat-sensitive film area into a plurality of independent rectangular areas. The main bridge surface of the infrared detector structure formed at this time also includes the first dielectric film and the second dielectric film, which is beneficial to film stress balance.

Preferably, the first dielectric film and the second dielectric film can be formed of materials such as silicon oxide and silicon nitride.

Here, the infrared detector structure shown in FIG. 2 is formed by first depositing the electrode film and then depositing the heat-sensitive film.

The present invention also includes another method flow for preparing the infrared detector structure shown in FIG. 2 . Specifically, firstly, deposit an infrared reflective film on the substrate; then, determine the position of the infrared reflective film and remove the infrared reflective film outside the position; in step A, after the deposition of the substrate, Coating a sacrificial layer material on the end face of the infrared reflective film to form a sacrificial layer; in step B, forming a groove for the connecting column of the infrared detector structure on the sacrificial layer; in step C, Depositing a conductive metal film on the sacrificial layer and in the groove, and removing the conductive metal film other than the position of the groove, so that the conductive metal film forms the connecting column; in step D, Deposit a heat-sensitive film on the sacrificial layer; in step E, deposit an electrode film on the heat-sensitive film; then, determine the position of the electrode film pattern formed by the electrode film and remove the Electrode film, and form a heat-sensitive film area, wherein, the electrode film pattern includes a positive electrode pattern and a negative electrode pattern respectively composed of comb-shaped patterns, and the comb teeth of the positive electrode pattern and the negative electrode pattern are arranged alternately, forming a back and forth bend folded strip-shaped area; in step F, determine the corresponding positions of the thermal insulation beam of the infrared detector structure, the main body bridge deck and the through hole, remove the electrode film and the heat-sensitive film outside the corresponding position, to form the heat-insulating beam, the main body bridge deck, the through hole and the heat-sensitive film pattern, wherein the heat-insulating beam is used to support the main body bridge deck suspended above the substrate, and pass through the connection The pillars are connected to the substrate, the main body bridge includes the electrode film pattern and the heat-sensitive film pattern, and the through-hole area is located at the bend of the strip-shaped area, dividing the heat-sensitive film area into A plurality of independent rectangular regions; in step G, removing the material of the sacrificial layer to obtain the infrared detector structure, wherein there is a gap between the bridge surface of the main body and the substrate.

Here, it should be noted that the above process of depositing the heat-sensitive film first and then depositing the electrode film is similar to the above-mentioned process of depositing the electrode film first and then depositing the heat-sensitive film. method is included here.

It will be apparent to those skilled in the art that the invention is not limited to the details of the above-described exemplary embodiments, but that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Accordingly, the embodiments should be regarded in all points of view as exemplary and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description, and it is therefore intended that the scope of the invention be defined by the appended claims rather than by the foregoing description. All changes within the meaning and range of equivalents of the elements are embraced in the present invention. Any reference sign in a claim should not be construed as limiting the claim concerned. In addition, it is obvious that the word "comprising" does not exclude other elements or steps, and the singular does not exclude the plural. A plurality of units or means stated in the device claims may also be realized by one unit or device through software or hardware. The words first, second, etc. are used to denote names and do not imply any particular order.

Claims (11)

1. An infrared detector structure, comprising: a substrate, a main body bridge deck, and: thermal insulation beams, used to support the bridge deck of the main body suspended above the substrate, so that the bridge deck of the main body is separated from the substrate; connecting posts for connecting the substrate and the insulating beams; Wherein, the substrate has an infrared reflective film on the end face of the main body bridge, and the main body bridge includes electrode film patterns and heat-sensitive film patterns, and the electrode film patterns include positive electrodes composed of comb-shaped patterns. pattern and negative electrode pattern, the comb teeth of the positive electrode pattern and the negative electrode pattern are arranged alternately, and a strip-shaped area bent back and forth is formed between them, and the strip-shaped area includes a heat-sensitive film area and a through-hole area, wherein the through-hole The area is located at the bend of the strip-shaped area, and divides the heat-sensitive film area into a plurality of independent rectangular areas. 2. The infrared detector structure according to claim 1, wherein the electrode film pattern and the heat-sensitive film pattern are stacked up and down and kept in electrical contact, and the electrode film forming the electrode film pattern can be positioned at the position where the heat-sensitive film pattern is formed. The lower part of the heat-sensitive film of the sensitive film pattern can also be located above the heat-sensitive film. 3. The infrared detector structure according to claim 1 or 2, wherein the comb-tooth pattern is a comb-tooth pattern of single-sided comb teeth and/or a comb-tooth pattern of double-sided comb teeth. 4. The infrared detector structure according to any one of claims 1 to 3, wherein the heat-sensitive thin films in the plurality of independent rectangular regions are connected in parallel to form a thermistor of the infrared detector structure. 5. The infrared detector structure according to any one of claims 1 to 4, wherein the bridge deck of the main body further comprises a dielectric thin film. 6. An uncooled infrared detector, wherein the uncooled infrared detector comprises the infrared detector structure according to any one of claims 1-5. 7. An infrared imager, wherein the infrared imager comprises the infrared detector structure according to any one of claims 1 to 5. 8. A focal plane array, wherein the focal plane array comprises an array formed by any one or more of the infrared detector structures according to any one of claims 1 to 5. 9. A method for preparing the infrared detector structure as claimed in claim 1, wherein the method comprises the steps of: - deposit infrared reflective film on the substrate; - determine the position of the infrared reflective film and remove the infrared reflective film outside the position; a coating a sacrificial layer material on the end surface of the substrate on which the infrared reflective film is deposited to form a sacrificial layer; b forming grooves for connection posts of the infrared detector structure on the sacrificial layer; c depositing a conductive metal film on the sacrificial layer and in the groove, and removing the conductive metal film outside the groove, so that the conductive metal film forms the connecting column; d depositing an electrode film on the sacrificial layer; - Determine the position of the electrode film pattern formed by the electrode film and remove the electrode film outside the position, wherein the electrode film pattern includes a positive electrode pattern and a negative electrode pattern respectively composed of comb-shaped patterns, the positive electrode The comb teeth of the pattern and the negative pattern are arranged in a staggered manner, forming a strip-shaped area bent back and forth between them; e depositing a heat-sensitive film on the end face of the sacrificial layer on which the electrode film pattern is formed; f Determine the corresponding positions of the thermal insulation beam, the bridge deck of the main body and the through hole of the infrared detector structure, and remove the electrode film and the heat sensitive film outside the corresponding position to form the thermal insulation beam and the main body The bridge deck and the through-hole area, wherein the heat-insulating beam is used to support the main body bridge deck to hang above the substrate, and is connected to the substrate through the connecting column, and the main body bridge deck includes The electrode film pattern and the heat-sensitive film pattern formed by the heat-sensitive film, the through-hole area is located at the bend of the strip-shaped area, and divides the heat-sensitive film area into a plurality of independent rectangular areas; g removing the material of the sacrificial layer to obtain the infrared detector structure, wherein there is a gap between the bridge surface of the main body and the substrate. 10. The method according to claim 9, wherein the method further comprises: - depositing a first dielectric thin film on said sacrificial layer; Wherein, the step d includes: - depositing an electrode film on said first dielectric film; Wherein, the method also includes: - depositing a second dielectric film on the heat-sensitive film; Wherein, the step f includes: Determine the corresponding positions of the thermal insulation beams of the infrared detector structure, the bridge deck of the main body, and the through holes, and remove the first dielectric film, the electrode film, the heat-sensitive film and the second film outside the corresponding positions. a dielectric film to form the heat-insulating beam, the main body bridge deck, and the through hole, wherein the heat-insulating beam is used to support the main body bridge deck to hang above the substrate, and through the connecting column and The substrates are connected, the main body bridge includes the electrode film pattern and the heat-sensitive film pattern formed by the heat-sensitive film, the through-hole area is located at the bend of the strip-shaped area, and the heat-sensitive The film area is divided into multiple independent rectangular areas. 11. A method for preparing the infrared detector structure as claimed in claim 1, wherein the method comprises the steps of: - deposit infrared reflective film on the substrate; - determine the position of the infrared reflective film and remove the infrared reflective film outside the position; A coating a sacrificial layer material on the end surface of the substrate deposited with the infrared reflective film to form a sacrificial layer; B forming grooves for connecting columns of the infrared detector structure on the sacrificial layer; C depositing a conductive metal film on the sacrificial layer and in the groove, and removing the conductive metal film outside the groove position, so as to form the connecting column by the conductive metal film; D depositing a heat-sensitive thin film on the sacrificial layer; E depositing an electrode film on the heat-sensitive film; - Determining the position of the electrode film pattern formed by the electrode film and removing the electrode film other than the position, and forming a heat-sensitive film area, wherein the electrode film pattern includes a positive electrode pattern composed of comb-shaped patterns respectively and the negative electrode pattern, the comb teeth of the positive electrode pattern and the negative electrode pattern are arranged alternately, and a strip-shaped area bent back and forth is formed between them; F Determine the corresponding positions of the thermal insulation beam, the bridge deck of the main body and the through hole of the infrared detector structure, and remove the electrode film and the heat sensitive film outside the corresponding position to form the thermal insulation beam and the main body The bridge deck, the through-hole area and the heat-sensitive film pattern, wherein the heat-insulating beam is used to support the bridge deck of the main body to hang above the substrate, and is connected to the substrate through the connecting column. The bridge surface of the main body includes the electrode film pattern and the heat-sensitive film pattern, and the through-hole area is located at the bend of the strip-shaped area, and divides the heat-sensitive film area into a plurality of independent rectangular areas; G removing the sacrificial layer material to obtain the infrared detector structure, wherein there is a gap between the bridge surface of the main body and the substrate.