Manufacturing method for array sensor elements

Abstract

This invention provides a technology that can improve the removal performance of deposits and residues during etching of dielectric films containing crystalline composite metal compounds. [Solution] The method for manufacturing an array sensor element comprises: a first step of forming a dielectric film containing a crystalline composite metal compound on a first electrode formed on a substrate; a second step of dry etching the dielectric film using a fluorine-based gas or a chlorine-based gas; and a third step of wet etching the dielectric film using a phosphoric acid-based etching solution while heating the dielectric film at a first temperature after the second step.

Description

Technical Field

[0004] , , , , , , , , , , ,

[0001] The present disclosure relates to a method for manufacturing an array sensor element.

Background Art

[0002] As a detection device in which elements having a structure in which a plurality of thin films including electrodes are laminated are arranged in an array, for example, an imaging device of Patent Document 1, an ultrasonic device of Patent Document 2, etc. are known. The elements used in these detection devices utilize flat panel display technology. Patent Document 3 discloses a method for manufacturing a flat panel display.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the dry etching of a dielectric film containing a crystalline metal compound constituting the above-described element, a compound of the dielectric film and an etching gas may adhere to the dielectric film, or a part of the dielectric film may remain as a residue without being removed. In Patent Document 3, it has been studied to eliminate etching residues and surface roughness generated in the dry etching of a silicon nitride film, which is an insulating film, by wet etching. However, in the case where the etching target is a dielectric film containing a crystalline metal compound, the removal of the above-described deposits and residues has not been studied. Therefore, in the etching of a dielectric film containing a crystalline composite metal compound, a technique capable of improving the removal performance of deposits and residues is desired.

Means for Solving the Problems

[0005] A first embodiment of the present disclosure provides a method for manufacturing an array sensor element. This method for manufacturing an array sensor element comprises: a first step of forming a dielectric film containing a crystalline composite metal compound on a first electrode formed on a substrate; a second step of dry etching the dielectric film using a fluorine-based gas or a chlorine-based gas; and a third step, after the second step, of wet etching the dielectric film using a phosphoric acid-based etching solution while heating the dielectric film at a first temperature. [Brief explanation of the drawing]

[0006] [Figure 1] A top view showing the schematic configuration of the array sensor element. [Figure 2] An explanatory diagram showing a magnified view of a portion of the AR range in Figure 1. [Figure 3] A cross-sectional view showing the position III-III in Figure 2. [Figure 4] A cross-sectional view showing the IV-IV position in Figure 2. [Figure 5] A flowchart illustrating the manufacturing method of an array sensor element. [Figure 6] Flowchart of the dielectric film formation process. [Figure 7] A diagram showing the state after the dielectric film has been deposited. [Figure 8] A diagram showing the state after the dielectric film has been deposited. [Figure 9] This diagram shows the state after dry etching of the dielectric film. [Figure 10] This diagram shows the state after dry etching of the dielectric film. [Figure 11] A diagram illustrating the preheating and wet etching of a dielectric film. [Figure 12] Measurement results showing the change in the etching rate of the dielectric film with respect to the temperature of the etching solution. [Figure 13] A diagram illustrating the preheating and wet etching of the dielectric film in the second embodiment. [Figure 14]A diagram illustrating the preheating and wet etching of the dielectric film in the third embodiment. [Modes for carrying out the invention]

[0007] A. First Embodiment: Figure 1 is a top view showing the schematic configuration of the array sensor element 100. Figure 1 shows arrows representing the mutually orthogonal X, Y, and Z directions. The X and Y directions are parallel to the horizontal plane. The Z direction is parallel to the vertical direction. The X, Y, and Z directions in Figure 1 and the X, Y, and Z directions in other figures point to the same directions. When specifying the direction, the positive direction indicated by the arrow is denoted as "+", and the negative direction opposite to the direction indicated by the arrow is denoted as "-", using both positive and negative signs in the direction notation. The +Z direction is also referred to as "up", and the -Z direction as "down".

[0008] The array sensor element 100 consists of a substrate 10 and a plurality of elements 20 arranged in an array on the substrate 10. Figure 1 shows an example of an array sensor element 100 having 16 elements 20. In the example shown in Figure 1, each element 20 is arranged in a 4x4 array along the X and Y directions. Alternatively, each element 20 may be arranged in a staggered pattern, alternating in the X or Y direction. Furthermore, the number of elements 20 in the array sensor element 100 is not limited to 16. The array sensor element 100 is used in flat panel displays, imaging devices for vein authentication, ultrasound devices, and the like.

[0009] The substrate 10 is made of a heat-resistant material such as glass or silicon. The substrate 10 is a rectangular plate. However, the shape of the substrate 10 may be other than a rectangular plate, such as a circle, ellipse, or polygon.

[0010] The element 20 has a structure in which a plurality of thin films including electrodes are stacked. The element 20 includes a first electrode 21, a dielectric film 22, and a second electrode 23, which will be described later. The first electrode 21, the dielectric film 22, and the second electrode 23 are stacked in this order from the -Z direction to the +Z direction. Hereinafter, the +Z direction is also referred to as the stacking direction.

[0011] FIG. 2 is an explanatory diagram showing an enlarged view of a partial range AR of FIG. 1. FIG. 3 is a cross-sectional view showing the position III-III of FIG. 2. FIG. 4 is a cross-sectional view showing the position IV-IV of FIG. 2. Hereinafter, the detailed configuration of the array sensor element 100 will be described with reference to FIGS. 2 to 4. In FIG. 2, the second insulating film 40 shown in FIGS. 3 and 4 is omitted.

[0012] A first insulating film 30 is formed on the +Z direction side of the substrate 10. The first insulating film 30 is formed of a material having insulating properties such as silicon oxide (SiO2) or silicon nitride (SiN).

[0013] A first electrode 21 is formed on the +Z direction side of the first insulating film 30. The first electrode 21 includes an element forming portion 26 for forming the element 20, a connection portion 27, and a wiring portion 28. The element forming portion 26 is formed at a position where the element 20 is disposed. The shape of the element forming portion 26 as viewed in the -Z direction is circular. The connection portion 27 connects the element forming portions 26 arranged adjacent to each other in the X direction. The wiring portion 28 is formed on the +X direction side of the element forming portion 26 at the end on the +X direction side and is connected to the element forming portion 26 at the end on the +X direction side. Electricity is supplied to the wiring portion 28 from the outside. That is, electricity is supplied to each element forming portion 26 via the wiring portion 28 and the connection portion 27. The first electrode 21 is formed of a material capable of controlling the crystal orientation of the dielectric film 22 stacked on the first electrode 21. In the present embodiment, the first electrode 21 is formed of titanium or molybdenum. Note that the first electrode 21 may include both titanium and molybdenum.

[0014] On the +Z direction side of the first insulating film 30 and the first electrode 21, a dielectric film 22 is formed. The dielectric film 22 is formed on the +Z direction side of the element formation part 26. The dielectric film 22 is further formed on the +Z direction side of the connection part 27 and on the part of the +Z direction side of the first insulating film 30 where the first electrode 21 is not laminated. The dielectric film 22 laminated on the +Z direction side of the element formation part 26 forms the element 20. The shape of the dielectric film 22 forming the element 20 is a circular shape with a diameter smaller than that of the element formation part 26 when viewed in the -Z direction. The dielectric film 22 contains a crystalline composite metal compound. In the present embodiment, the composite metal compound includes a compound semiconductor composed of copper, selenium, and at least one of indium and gallium. The above compound semiconductor is called copper indium gallium selenide (CIGS).

[0015] On the +Z direction side of the dielectric film 22 laminated on the element formation part 26, a second electrode 23 is formed. The shape of the second electrode 23 when viewed in the -Z direction is a circular shape with a diameter smaller than that of the dielectric film 22 constituting the element 20. The second electrode 23 is formed of a metal material such as titanium or molybdenum.

[0016] On the +Z direction side of the first insulating film 30, the first electrode 21, the dielectric film 22, and the second electrode 23, a second insulating film 40 is formed. The second insulating film 40 is formed so as to cover the part of the above-described members excluding the central part and the wiring part 28 of the second electrode 23. The second insulating film 40 is formed of a material having insulation properties such as SiO2 or SiN.

[0017] A second electrode wiring 51 is formed on the +Z direction side of the second electrode 23 and the second insulating film 40. The second electrode wiring 51 connects the second electrode 23 of each element 20, which is arranged along the Y direction, to the second electrode drive wiring 52 provided at the +Y direction end of each row. Here, the second electrode drive wiring 52 is a wiring formed in the same layer as the first electrode 21 using the same material as the first electrode 21, on the +Y direction side of the element 20 located at the +Y direction end. Electricity is supplied to the second electrode drive wiring 52 from the outside. That is, electricity is supplied to the second electrode 23 of each element 20 via the second electrode drive wiring 52 and the second electrode wiring 51. The second electrode wiring 51 is laminated on the second electrode 23 so as to cover its outer circumference. The shape of the second electrode wiring 51 laminated on the second electrode 23 is annular when viewed from the Z direction. The second electrode wiring 51 is formed from a metallic material such as titanium or molybdenum.

[0018] Figure 5 is a flowchart showing the manufacturing method of the array sensor element 100. First, in step S10, a first insulating film 30 is formed on the +Z direction side of the substrate 10 by sputtering. Note that the first insulating film 30 is not limited to sputtering and may be formed by any known film deposition technique.

[0019] In step S20, the first electrode 21 is formed on the +Z side of the first insulating film 30. Specifically, after depositing the first electrode 21 by sputtering, a resist mask is formed on the first electrode 21, and the first electrode 21 is patterned by dry etching. The second electrode drive wiring 52 is also formed at the same time as the first electrode 21. Note that the first electrode 21 and the second electrode drive wiring 52 may be formed by any known film deposition technique, not limited to the method described above. Also, the second electrode drive wiring 52 may be formed separately from the first electrode 21.

[0020] In step S30, a dielectric film formation process is performed. Details of the dielectric film formation process will be described later.

[0021] In step S40, the second electrode 23 is formed on the +Z side of the dielectric film 22 stacked on the element formation portion 26 of the first electrode 21. Specifically, after depositing the second electrode 23 by sputtering, a resist mask is formed on the second electrode 23, and the second electrode 23 is patterned by dry etching. Note that the second electrode 23 is not limited to the method described above, but may be formed by any known film deposition technique.

[0022] In step S50, the second insulating film 40 is deposited on the +Z direction side of the first insulating film 30, the first electrode 21, the dielectric film 22, and the second electrode 23. Specifically, after depositing the second insulating film 40 by sputtering, a resist mask is formed on the second insulating film 40, and the second insulating film 40 is patterned by dry etching. Note that the second insulating film 40 is not limited to the method described above, but may be formed by any known film deposition technique.

[0023] In step S60, the second electrode wiring 51 is formed on the +Z side of the second electrode 23, the second insulating film 40, and the second electrode drive wiring 52. Specifically, after depositing the second electrode wiring 51 by sputtering, a resist mask is formed on the second electrode wiring 51, and the second electrode wiring 51 is patterned by dry etching. Note that the second electrode wiring 51 is not limited to the method described above, but may be formed by any known film deposition technique. The array sensor element 100 is manufactured as described above.

[0024] Figure 6 is a flowchart of the dielectric film formation process. First, in step S110, a dielectric film 22 is deposited by sputtering on the +Z direction side of the first insulating film 30 and the first electrode 21. Figures 7 and 8 show the state after the dielectric film 22 has been deposited. Figure 7 is a cross-sectional view corresponding to position III-III in Figure 2, and Figure 8 is a cross-sectional view corresponding to position IV-IV in Figure 2. Note that the dielectric film 22 may be deposited by any known film deposition technique, not limited to sputtering. Step S110 is also called the first step.

[0025] In step S120, dry etching is performed on the dielectric film 22 deposited in step S110. Specifically, a resist mask is formed on the dielectric film 22 by photolithography, and the dielectric film 22 is patterned by dry etching using a fluorine-based gas or a chlorine-based gas. Here, a fluorine-based gas is a gas containing fluorine, and a chlorine-based gas is a gas containing chlorine. Step S120 is also called the second step. Figures 9 and 10 show the state after dry etching of the dielectric film 22. Figure 9 is a cross-sectional view corresponding to position III-III in Figure 2, and Figure 10 is a cross-sectional view corresponding to position IV-IV in Figure 2. In this embodiment, as shown in Figures 9 and 10, the compound 201 of the dielectric film 22 and etching gas generated during dry etching adheres to the side surface of the dielectric film 22 constituting the element 20. In addition, a portion of the dielectric film 22 that could not be completely removed by dry etching remains as residue 202 on the wiring portion 28 and the second electrode drive wiring 52.

[0026] Figure 11 illustrates the preheating and wet etching of the dielectric film 22. In Figure 11, the etching solution and water are each given different hatching patterns. Steps S130 and S140 in Figure 6 will be described below with reference to Figure 11.

[0027] In step S130, the dielectric film 22 is preheated to a second temperature. Here, the second temperature is a temperature lower than or equal to the first temperature, which will be described later. In step S130, the array sensor element 100 is introduced into the pre-chamber 310 and preheated in an etching atmosphere within the pre-chamber 310. Here, the etching atmosphere refers to the atmosphere in which the gas of the etching solution used in step S140, which will be described later, is present. The gas of the etching solution at the second temperature is introduced into the pre-chamber 310. As a result, the dielectric film 22 is heated to the second temperature. Step S130 is also called the preheating step.

[0028] In step S140, the dielectric film 22 is wet-etched while being heated at a first temperature. Step S140 is also called the third step. In step S140, the array sensor element 100 is moved from the preparatory chamber 310 to the first etching tank 320 by a belt conveyor 350. The array sensor element 100 may be moved by a transfer means other than the belt conveyor 350. A first nozzle 321 is provided at the inlet of the first etching tank 320. The first nozzle 321 drips a phosphoric acid-based etching solution at a first temperature downwards. In this embodiment, the first temperature is 50°C or higher and 60°C or lower. A phosphoric acid-based etching solution means an etching solution containing phosphoric acid. The first nozzle 321 has an opening that extends in a first direction which is perpendicular to the vertical direction and intersects the direction of movement of the array sensor element 100. Preferably, the length of the opening of the first nozzle 321 in the first direction, i.e., the width of the first nozzle 321, is greater than or equal to the length of the array sensor element 100 in the first direction. Note that the first nozzle 321 does not necessarily extend along the first direction, but may be provided in multiple locations along the first direction. When the array sensor element 100 moves from the spare chamber 310 to the first etching tank 320, it passes below the first nozzle 321. As a result, etching solution is dripped onto the upper surface of the dielectric film 22, wetting the dielectric film 22 with the etching solution. It is preferable that the first nozzle 321 drips the etching solution so that the entire upper surface of the dielectric film 22 is wetted with the etching solution. The on / off switching of the etching solution discharge from the first nozzle 321 and the movement of the belt conveyor 350 are controlled by the control unit 360. The control unit 360 is, for example, a computer equipped with a processor and a memory device.

[0029] Figure 12 shows the measurement results of the change in the etching rate of the dielectric film 22 with respect to the temperature of the etching solution. As shown in Figure 12, in the range where the etching solution is between 50°C and 60°C, i.e., in the first temperature range, the etching rate of the dielectric film 22 is higher than when the etching solution is at 40°C.

[0030] The first etching tank 320 shown in Figure 11 is equipped with a second nozzle 322 and a first storage unit 323. The second nozzle 322 is located above the first storage unit 323 and showers the etching solution downwards. The first storage unit 323 is a box-shaped container with an open top where the etching solution is stored. The first storage unit 323 is provided to be movable in the vertical direction. The on / off switching of the etching solution discharge from the second nozzle 322 and the vertical movement of the first storage unit 323 are controlled by the control unit 360.

[0031] Outside the first etching tank 320, there is a second storage section 324 where etching solution is stored. The second storage section 324 is, for example, a tank. Inside the second storage section 324, there is a heater 325. The heater 325 heats the etching solution stored in the second storage section 324 to a first temperature. The first etching tank 320 and the second storage section 324 are connected by piping. The etching solution stored in the second storage section 324 is supplied to the second nozzle 322 through the piping and showered from the second nozzle 322. The etching solution stored in the first storage section 323 is discharged to the second storage section 324 through the piping.

[0032] The second nozzle 322 heats the first etching tank 320 by showering it with etching solution before the array sensor element 100 enters the first etching tank 320. The second nozzle 322 does not discharge etching solution while the array sensor element 100 is moving from the pre-chamber 310 to the first etching tank 320. After the array sensor element 100 enters the first etching tank 320, the second nozzle 322 showers etching solution at a first temperature onto the upper surface of the dielectric film 22. This heats the dielectric film 22 to a first temperature.

[0033] With the array sensor element 100 inside the first etching tank 320 and having moved above the first storage section 323, the control unit 360 moves the first storage section 323 upward to immerse the array sensor element 100 in the etching solution. The control unit 360 moves the first storage section 323 upward until the liquid level of the etching solution in the first storage section 323 is above the upper surface of the dielectric film 22. In other words, the control unit 360 raises the liquid level of the etching solution inside the first etching tank 320.

[0034] The array sensor element 100 is oscillated horizontally in the first etching tank 320 with the upper surface of the dielectric film 22 wet with the etching solution. The array sensor element 100 is oscillated horizontally, for example, by the horizontal oscillation of the belt conveyor 350 on which the array sensor element 100 is placed, under the control of the control unit 360. In other words, the substrate 10 is oscillated horizontally with the upper surface of the dielectric film 22 wet with the etching solution. The array sensor element 100 may be oscillated horizontally while immersed in the etching solution, or it may be oscillated horizontally while not immersed in the etching solution. The above-described process in the first etching tank 320 removes the compound 201 and residue 202 from the array sensor element 100.

[0035] After processing in the first etching tank 320 is completed, the array sensor element 100 is moved from the first etching tank 320 to the second etching tank 330 by a belt conveyor 350. In the second etching tank 330, wet etching is performed while heating the dielectric film 22 at a first temperature, similar to the first etching tank 320. The configuration of the second etching tank 330 is the same as that of the first etching tank 320, except that it does not have a first nozzle 321. The processing in the second etching tank 330 is the same as the processing in the first etching tank 320, except that the first nozzle 321 does not drip etching solution onto the upper surface of the dielectric film 22. Therefore, the explanation of the processing in the second etching tank 330 is omitted.

[0036] After processing in the second etching tank 330 is completed, the array sensor element 100 is moved from the second etching tank 330 to the washing tank 340 by a belt conveyor 350. Inside the washing tank 340 are a third nozzle 341 and a third storage section 342. The third nozzle 341 is located above the third storage section 342 and showers water downwards. The third storage section 342 is a box-shaped container with an open top where water is stored. The on / off switching of water discharge from the third nozzle 341 is controlled by the control unit 360. In the washing tank 340, water is showered onto the upper surface of the dielectric film 22 from the third nozzle 341. This cleans the array sensor element 100. Alternatively, the array sensor element 100 may be moved directly from the first etching tank 320 to the washing tank after processing in the first etching tank 320 is completed. In other words, processing in the second etching tank 330 is not required. As described above, the dielectric film formation process is carried out.

[0037] According to the first embodiment described above, the method for manufacturing the array sensor element 100 includes a first step of forming a dielectric film 22 containing a crystalline composite metal compound on a first electrode 21, a second step of dry etching the dielectric film 22 using a fluorine-based gas or a chlorine-based gas, and a third step of wet etching the dielectric film 22 using a phosphoric acid-based etching solution while heating the dielectric film 22 at a first temperature after the second step. Therefore, by performing wet etching after dry etching in the etching of the dielectric film 22 containing a crystalline composite metal compound, the removal performance of compounds 201 between the dielectric film 22 and the etching gas that adhere to the dielectric film 22, and residues 202 which are a part of the dielectric film 22 that could not be completely removed by dry etching, can be improved. Since the dielectric film 22 contains a crystalline composite metal compound, the crystallinity of the composite metal compound differs depending on the position within the dielectric film 22, resulting in differences in the etching rate of dry etching. As a result, a part of the dielectric film 22 remains as residues 202. In this embodiment, the removal performance of such residues 202 can be improved.

[0038] If compound 201 adheres to the surface of the dielectric film 22 constituting the element 20, there is a high probability that the first electrode 21 and the second electrode 23 will short-circuit via compound 201. When current flows between the first electrode 21 and the second electrode 23 via compound 201 adhered to the surface of the dielectric film 22, it becomes noise, reducing the sensitivity of the array sensor element 100. In this embodiment, since the removal performance of compound 201 can be improved, the reduction in the sensitivity of the array sensor element 100 can be suppressed.

[0039] If residue 202 remains on the wiring section 28, and another wiring to supply electricity to the wiring section 28 is stacked on top of the wiring section 28, the resistance value of the connection between the wiring section 28 and the other wiring will increase. The same is true if residue 202 remains on the second electrode drive wiring 52. In this embodiment, the performance of removing residue 202 can be improved, so the increase in the resistance value of the connection described above can be suppressed.

[0040] Furthermore, in this embodiment, the first temperature is 50°C or higher and 60°C or lower. As shown in Figure 12, when the etching solution is 50°C or higher and 60°C or lower, the etching rate of the dielectric film 22 is higher than when the etching solution is 40°C. When the etching rate is low, the time required for wet etching increases, corrosion of the resist mask by the etching solution progresses, and the accuracy of the patterning of the dielectric film 22 decreases. Therefore, by heating the dielectric film 22 at the first temperature, the time required for wet etching can be shortened. In addition, the decrease in the accuracy of the patterning of the dielectric film 22 can be suppressed.

[0041] Furthermore, in this embodiment, the manufacturing method of the array sensor element 100 includes a preheating step in which the dielectric film 22 is preheated to a second temperature after the second step and before the third step. When the dielectric film 22 is preheated, the surface tension of the etching solution in contact with the dielectric film 22 is lower compared to when the dielectric film 22 is not preheated, thus reducing the likelihood of the dielectric film 22 repelling the etching solution. When the dielectric film 22 repels the etching solution, air bubbles tend to remain on the surface of the dielectric film 22, reducing the accuracy of wet etching. In this embodiment, since the dielectric film 22 is preheated, the reduction in the accuracy of wet etching can be suppressed.

[0042] Furthermore, in this embodiment, the second temperature is lower than or equal to the first temperature. Therefore, it is possible to suppress excessive preheating of the dielectric film 22.

[0043] Furthermore, in this embodiment, in the third step, an etching solution at the first temperature is showered onto the upper surface of the dielectric film 22. This allows the upper surface of the dielectric film 22 to be efficiently wetted with the etching solution.

[0044] Furthermore, in this embodiment, in the third step, the liquid level of the etching solution is raised in the tank in which the dielectric film 22 is immersed in the etching solution so that the liquid level of the etching solution is above the upper surface of the dielectric film 22. As a result, the dielectric film 22 is immersed in the etching solution, and the time required for wet etching can be shortened.

[0045] Furthermore, in this embodiment, the substrate 10 is oscillated horizontally in the third step. This makes it possible to remove air bubbles adhering to the surface of the dielectric film 22.

[0046] B. Second Embodiment: In the second embodiment, steps S130 and S140 of the dielectric film formation process differ from those in the first embodiment. The manufacturing method of the array sensor element 100, other than steps S130 and S140, and the configuration of each part of the array sensor element 100 are the same as in the first embodiment.

[0047] Figure 13 illustrates the preheating and wet etching of the dielectric film 22 in the second embodiment. In the second embodiment, in step S130, the dielectric film 22 is preheated at the entrance to the first etching bath 320, rather than in the pre-chamber 310. In the second embodiment, the first nozzle 321 drips etching solution at the second temperature downwards. The array sensor element 100 passes below the first nozzle 321 as it moves from the pre-chamber 310 to the first etching bath 320. This causes the etching solution at the second temperature to drip onto the upper surface of the dielectric film 22, wetting the dielectric film 22 with the etching solution. In this way, the dielectric film 22 is preheated to the second temperature. It is preferable that the first nozzle 321 drips the etching solution so that the entire upper surface of the dielectric film 22 is wet with the etching solution.

[0048] In step S140, the second nozzle 322 showers the upper surface of the dielectric film 22 with etching solution at a first temperature after the array sensor element 100 has entered the first etching tank 320. This heats the dielectric film 22 to the first temperature. With the array sensor element 100 inside the first etching tank 320 and above the first storage unit 323, the control unit 360 moves the first storage unit 323 upward to immerse the array sensor element 100 in the etching solution. The array sensor element 100 is also oscillated horizontally inside the first etching tank 320 with the upper surface of the dielectric film 22 wet with the etching solution.

[0049] After processing in the first etching tank 320 is completed, the array sensor element 100 is moved from the first etching tank 320 to the second etching tank 330 by a belt conveyor 350. In the second etching tank 330, the same processing as in the first etching tank 320 is performed. After processing in the second etching tank 330 is completed, the array sensor element 100 is moved from the second etching tank 330 to the washing tank 340 by a belt conveyor 350, where it is washed. Alternatively, the array sensor element 100 may be moved directly from the first etching tank 320 to the washing tank after processing in the first etching tank 320 is completed.

[0050] According to the second embodiment described above, in the preheating step, an etching solution at a second temperature is dripped onto the upper surface of the dielectric film 22, wetting the dielectric film 22 with the etching solution. Therefore, as described in the first embodiment, the surface tension of the etching solution in contact with the dielectric film 22 is reduced, which can suppress a decrease in the accuracy of wet etching.

[0051] C. Third Embodiment: In the third embodiment, steps S130 and S140 of the dielectric film formation process differ from those in the first embodiment. The manufacturing method of the array sensor element 100, other than steps S130 and S140, and the configuration of each part of the array sensor element 100 are the same as in the first embodiment.

[0052] Figure 14 illustrates the preheating and wet etching of the dielectric film 22 in the third embodiment. In the third embodiment, in step S130, the dielectric film 22 is preheated in the first etching tank 320. In the third embodiment, the pre-chamber 310 is not used. The second nozzle 322 showers the upper surface of the dielectric film 22 with etching solution at a second temperature after the array sensor element 100 has entered the first etching tank 320. This preheats the dielectric film 22 to the second temperature. Here, the flow rate of etching solution discharged from the second nozzle 322 is smaller than the flow rate of etching solution discharged from the second nozzle 322 in the second etching tank 330 in the third step, which will be described later. After the preheating of the dielectric film 22 in the first etching tank 320 is completed, the array sensor element 100 is moved from the first etching tank 320 to the second etching tank 330 by the belt conveyor 350.

[0053] In step S140, the dielectric film 22 is wet-etched in the second etching tank 330. In the second etching tank 330, wet etching is performed while heating the dielectric film 22 at a first temperature, similar to the first embodiment. Specifically, the second nozzle 322 of the second etching tank 330 showers the upper surface of the dielectric film 22 with etching solution at the first temperature after the array sensor element 100 has entered the second etching tank 330. This heats the dielectric film 22 to the first temperature. Furthermore, once the array sensor element 100 has entered the second etching tank 330 and moved above the first storage section 323 of the second etching tank 330, the control unit 360 moves the first storage section 323 upward to immerse the array sensor element 100 in the etching solution. The array sensor element 100 is also oscillated horizontally within the second etching tank 330, with the upper surface of the dielectric film 22 wet with etching solution. After processing in the second etching tank 330 is completed, the array sensor element 100 is moved from the second etching tank 330 to the washing tank 340 by the belt conveyor 350, where it is washed.

[0054] According to the third embodiment described above, in the preheating step, the etching solution at the second temperature is showered onto the upper surface of the dielectric film 22. Therefore, as described in the first embodiment, the surface tension of the etching solution in contact with the dielectric film 22 is reduced, which can suppress a decrease in the accuracy of wet etching.

[0055] D. Other embodiments: (D-1) In the above embodiment, the composite metal compound contained in the dielectric film 22 includes a compound semiconductor composed of copper, selenium, and at least one of indium and gallium. In contrast, the composite metal compound may be a piezoelectric material. Furthermore, the piezoelectric composite metal compound may contain one or more transition metal elements. The transition metal elements may include at least one of molybdenum and niobium. Note that the transition metal elements may not include either molybdenum or niobium. Also, the piezoelectric composite metal compound may not contain any transition metal elements.

[0056] (D-2) In the above embodiment, the first temperature is 50°C or higher and 60°C or lower. In contrast, the first temperature may be less than 50°C or more than 60°C.

[0057] (D-3) In the above embodiment, the method for manufacturing the array sensor element 100 includes a preheating step. However, the method for manufacturing the array sensor element 100 does not have to include a preheating step.

[0058] (D-4) In the above embodiment, the second temperature is a temperature lower than or equal to the first temperature. In contrast, the second temperature may be a temperature higher than the first temperature.

[0059] (D-5) In the above embodiment, in the third step, an etching solution at the first temperature is showered toward the upper surface of the dielectric film 22. In contrast, in the third step, it is not necessary to shower the etching solution toward the upper surface of the dielectric film 22.

[0060] (D-6) In the above embodiment, in the third step, the liquid level of the etching solution in the tank in which the dielectric film 22 is immersed is raised so that the liquid level of the etching solution is above the upper surface of the dielectric film 22. In contrast, in the third step, it is not necessary to raise the liquid level of the etching solution in the tank in which the dielectric film 22 is immersed so that the liquid level of the etching solution is above the upper surface of the dielectric film 22.

[0061] (D-7) In the above embodiment, the substrate 10 is oscillated horizontally in the third step. However, in the third step, the substrate 10 does not need to be oscillated horizontally.

[0062] (D-8) In the above embodiment, the first electrode 21 contains at least one of titanium and molybdenum. In contrast, the first electrode 21 does not have to contain either titanium or molybdenum.

[0063] (D-9) In the above embodiment, a first insulating film 30 is formed on the +Z side of the substrate 10. In contrast, instead of the first insulating film 30, a TFT layer, a planarization layer, and a passivation layer may be formed on the +Z side of the substrate 10 in this order from the -Z direction to the +Z direction. The TFT layer is a layer that forms a thin film transistor. The planarization layer is formed from, for example, a photosensitive resin. The passivation layer is formed from, for example, SiN.

[0064] (D-10) In the above embodiment, the shape of the element formation portion 26 of the first electrode 21, the dielectric film 22 constituting the element 20, and the second electrode 23 when viewed in the -Z direction is circular. In contrast, the shape of the element formation portion 26 of the first electrode 21, the dielectric film 22 constituting the element 20, and the second electrode 23 when viewed in the -Z direction is not limited to a circular shape, but may be elliptical, rounded rectangular, or the like.

[0065] E. Other forms: This disclosure is not limited to the embodiments described above, and can be implemented in various forms without departing from its spirit. For example, this disclosure can also be implemented in the following forms. The technical features in the embodiments described below that correspond to the technical features in each of the forms described below can be replaced or combined as appropriate in order to solve some or all of the problems of this disclosure, or to achieve some or all of the effects of this disclosure. Furthermore, if such technical features are not described as essential in this specification, they can be deleted as appropriate.

[0066] (1) According to a first embodiment of the present disclosure, a method for manufacturing an array sensor element is provided. This method for manufacturing an array sensor element comprises: a first step of forming a dielectric film containing a crystalline composite metal compound on a first electrode formed on a substrate; a second step of dry etching the dielectric film using a fluorine-based gas or a chlorine-based gas; and a third step, after the second step, of wet etching the dielectric film using a phosphoric acid-based etching solution while heating the dielectric film at a first temperature. With this configuration, in etching a dielectric film containing a crystalline composite metal compound, performing wet etching after dry etching can improve the removal performance of compounds between the dielectric film and the etching gas that adhere to the dielectric film, as well as residues that are parts of the dielectric film that could not be completely removed by dry etching.

[0067] (2) In the above embodiment, the first temperature may be 50°C or higher and 60°C or lower. This configuration allows for a reduction in the time required for wet etching of the dielectric film. Furthermore, it helps to suppress a decrease in the accuracy of the dielectric film patterning.

[0068] (3) In the above embodiment, a preheating step may be included after the second step and before the third step, in which the dielectric film is preheated to a second temperature. When the dielectric film is preheated, the surface tension of the etching solution in contact with the dielectric film is lower compared to when the dielectric film is not preheated, thus reducing the likelihood of the dielectric film repelling the etching solution. When the dielectric film repels the etching solution, air bubbles are more likely to remain on the surface of the dielectric film, reducing the accuracy of wet etching. This configuration can suppress the reduction in the accuracy of wet etching.

[0069] (4) In the above embodiment, the second temperature may be a temperature lower than or equal to the first temperature. This configuration can suppress excessive preheating of the dielectric film.

[0070] (5) In the above embodiment, in the preheating step, the etching solution at the second temperature may be dropped onto the upper surface of the dielectric film to wet the dielectric film with the etching solution. With this configuration, the decrease in the accuracy of wet etching can be suppressed, similar to configuration (3).

[0071] (6) In the above embodiment, the etching solution at the second temperature may be showered onto the upper surface of the dielectric film during the preheating step. With this configuration, the decrease in the accuracy of wet etching can be suppressed, similar to configuration (3).

[0072] (7) In the above embodiment, in the third step, the etching solution at the first temperature may be showered toward the upper surface of the dielectric film. This configuration allows for efficient wetting of the upper surface of the dielectric film with the etching solution.

[0073] (8) In the above embodiment, in the third step, the liquid level of the etching solution may be raised in the tank in which the dielectric film is immersed in the etching solution so that the liquid level of the etching solution is above the upper surface of the dielectric film. In this configuration, the dielectric film is immersed in the etching solution, thus reducing the time required for wet etching.

[0074] (9) In the above embodiment, the substrate may be swung horizontally in the third step. This configuration makes it possible to remove air bubbles adhering to the surface of the dielectric film.

[0075] (10) In the above embodiment, the composite metal compound may be a piezoelectric material.

[0076] (11) In the above embodiment, the composite metal compound may contain one or more transition metal elements.

[0077] (12) In the above embodiment, the transition metal element may include at least one of molybdenum and niobium.

[0078] (13) In the above embodiment, the composite metal compound may include a compound semiconductor composed of copper, selenium, and at least one of indium and gallium.

[0079] (14) In the above embodiment, the first electrode may contain at least one of titanium and molybdenum. [Explanation of Symbols]

[0080] 10...Substrate, 20...Element, 21...First electrode, 22...Dielectric film, 23...Second electrode, 26...Element formation section, 27...Connection section, 28...Wiring section, 30...First insulating film, 40...Second insulating film, 51...Second electrode wiring, 52...Second electrode drive wiring, 100...Array sensor element, 201...Compound, 202...Residue, 310...Preparation chamber, 320...First etching tank, 321...First nozzle, 322...Second nozzle, 323...First storage section, 324...Second storage section, 325...Heater, 330...Second etching tank, 340...Water washing tank, 341...Third nozzle, 342...Third storage section, 350...Belt conveyor, 360...Control section

Claims

1. A method for manufacturing an array sensor element, A first step involves forming a dielectric film containing a crystalline composite metal compound on a first electrode formed on a substrate, A second step involves dry etching the dielectric film using a fluorine-based gas or a chlorine-based gas, The process includes a third step, in which the dielectric film is wet-etched using a phosphoric acid-based etching solution while the dielectric film is heated at a first temperature, after the second step, A method for manufacturing array sensor elements.

2. A method for manufacturing an array sensor element according to claim 1, The first temperature is 50°C or higher and 60°C or lower. A method for manufacturing array sensor elements.

3. A method for manufacturing an array sensor element according to claim 1, The method includes a preheating step, after the second step and before the third step, in which the dielectric film is preheated to a second temperature. A method for manufacturing array sensor elements.

4. A method for manufacturing an array sensor element according to claim 3, The second temperature is a temperature lower than or equal to the first temperature. A method for manufacturing array sensor elements.

5. A method for manufacturing an array sensor element according to claim 3, In the preheating step, the etching solution at the second temperature is dropped onto the upper surface of the dielectric film, and the dielectric film is wetted with the etching solution. A method for manufacturing array sensor elements.

6. A method for manufacturing an array sensor element according to claim 3, In the preheating step, the etching solution at the second temperature is showered toward the upper surface of the dielectric film. A method for manufacturing array sensor elements.

7. A method for manufacturing an array sensor element according to claim 2, In the third step, the etching solution at the first temperature is showered toward the upper surface of the dielectric film. A method for manufacturing array sensor elements.

8. A method for manufacturing an array sensor element according to claim 1, In the third step, in the tank in which the dielectric film is immersed in the etching solution, the liquid level of the etching solution is raised so that the liquid level of the etching solution is above the upper surface of the dielectric film. A method for manufacturing array sensor elements.

9. A method for manufacturing an array sensor element according to claim 1, In the third step, the substrate is swung horizontally. A method for manufacturing array sensor elements.

10. A method for manufacturing an array sensor element according to claim 1, The aforementioned composite metal compound is a piezoelectric material. A method for manufacturing array sensor elements.

11. A method for manufacturing an array sensor element according to claim 10, The composite metal compound comprises one or more transition metal elements. A method for manufacturing array sensor elements.

12. A method for manufacturing an array sensor element according to claim 11, The transition metal element includes at least one of molybdenum and niobium. A method for manufacturing array sensor elements.

13. A method for manufacturing an array sensor element according to claim 1, The aforementioned composite metal compound includes a compound semiconductor composed of copper, selenium, and at least one of indium and gallium. A method for manufacturing array sensor elements.

14. A method for manufacturing an array sensor element according to claim 1, The first electrode comprises at least one of titanium and molybdenum. A method for manufacturing array sensor elements.

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