TWI428030B - Film structure and sound sensing device - Google Patents

Description

Film structure and sound sensing device

The present invention relates to a film structure and a sound sensing device having the film structure, and more particularly to a diaphragm having process residual stress immunological characteristics and a sound sensing device having the same.

Nowadays, vision and hearing are the two most direct sensory responses of human beings. Therefore, scientists have been developing various regenerative visual and auditory related systems for a long time. However, with the increasing demand for sensory quality in recent years, and 3C products (Computer, Communication, Consumer Electronics) in the pursuit of short, light and thin, a power-saving, lightweight, ergonomically designed sound sense Measuring devices (also known as microphones), whether applied to personal mobile phones, car systems, personal computers or multimedia environments, there will be a large number of needs and applications in this area.

Many current sound sensing devices are fabricated through microelectromechanical processes or complementary gold oxide semiconductor (CMOS) processes. However, the process stress encountered during the process can cause many yield problems, and the residual stresses at different locations on the same wafer are not the same. As such, the film properties at different locations on the same wafer will be different.

The invention provides a film structure and a sound sensing device having the film structure, so as to solve the problem that the film characteristics of different wafer positions are significantly different due to process residual stress in the process.

The invention provides a film structure comprising a film body, a plurality of sets of first slots, a plurality of sets of second slots and a plurality of connecting portions. The film body has a central region and a plurality of side regions located around the central region and a plurality of gradient stress suppression regions, wherein each gradient stress suppression region is located between adjacent side edge regions. Each set of first slots is located in one of the side regions, and each set of first slots includes a plurality of first slot patterns that are staggered. Each set of second slots is located in one of the gradient stress suppression zones, and each set of second slots includes a plurality of second slotted patterns. Each of the connecting portions is located between each of the second slotted second slot patterns to connect the film body located in the gradient stress suppression region with the film body located in the central region.

The invention provides a sound sensing device structure comprising a substrate, a film and a metal back plate. The film is located on the substrate, and a first air chamber is formed between one surface of the film and the substrate, wherein the film comprises a film body, a plurality of sets of first slots, a plurality of sets of second slots, and a plurality of connecting portions. The film body has a central region and a plurality of side regions located around the central region and a plurality of gradient stress suppression regions, wherein each gradient stress suppression region is located between adjacent side edge regions. Each set of first slots is located in one of the side regions, and each set of first slots includes a plurality of first slot patterns that are staggered. Each set of second slots is located in one of the gradient stress suppression zones, and each set of second slots includes a plurality of second slotted patterns. Each of the connecting portions is located between each of the second slotted second slot patterns to connect the film body located in the gradient stress suppression region with the film body located in the central region. The metal backing plate is positioned over the film with a second air chamber between the metal backing plate and the other surface of the film.

Based on the above, the first groove pattern provided in the side region of the film body of the present invention can release stress, and the second groove pattern and the joint portion provided in the gradient stress suppression region of the film body can suppress the gradient stress effect. . Therefore, the film structure of the present invention can not only release stress, but also the film properties are not susceptible to gradient stress. Thus, after a plurality of processes, the uniformity of film structure characteristics at different positions on the wafer is better.

The above described features and advantages of the present invention will be more apparent from the following description.

1 is a top plan view of a film structure in accordance with an embodiment of the present invention. Referring to FIG. 1 , the film structure of the embodiment includes a film body 100 , a plurality of sets of first slots 103 , a plurality of sets of second slots 105 , and a plurality of connecting portions 108 .

The film body 100 has a central region 102, a plurality of side regions 104, and a plurality of gradient stress suppression regions 106. The side regions 104 and the gradient stress suppression regions 106 are located around the central region 102, and each gradient stress suppression region 106 is located between adjacent side edge regions 104. The outline of the film body 100 can be square, circular, rectangular or polygonal. In the present embodiment (the embodiment shown in Fig. 1), the outline of the film body 100 is exemplified by a square, but the invention is not limited thereto. The material of the film body 100 may be any material or a material suitable for the diaphragm, such as carbon-based polymers, silicon, silicon nitride, and polycrystalline silicon. ), amorphous silicon, silicon dioxide, silicon carbide, and germanium, gallium, arsenide, carbon, titanium ), gold, iron, copper, chromium, tungsten, aluminum, platinum, nickel, tantalum, etc. Its alloy.

Since the outline of the film body 100 of the present embodiment is square, the film body 100 has four side regions 104 and four gradient stress suppression regions 106. Further, the gradient stress suppression regions 106 are located at the four corners of the film body 100. Similarly, according to other embodiments, if the outline of the film body 100 is rectangular, the film body 100 also has four side regions 104 and four gradient stress suppression regions 106, and the gradient stress suppression region 106 is located on the film body 100. Four corners.

A plurality of sets of first slots 103 are located in the side regions 104. In other words, each set of first slots 103 is correspondingly disposed in one of the side regions 104. In addition, each set of first slots 103 includes a plurality of first slot patterns 103a, 103b, 103c arranged in a staggered manner. In the present embodiment, the first groove patterns 103a, 103b, 103c are grooves that penetrate the film body 100. Further, in the present embodiment, each set of first slots 103 has at least three first slot patterns 103a, 103b, 103c, and the at least three first slot patterns 103a, 103b, 103c are staggered. However, the present invention does not limit the number and length of the first groove patterns in each of the first grooves, as long as the first groove patterns in each of the first grooves are staggered with each other.

A plurality of sets of second slots 105 are located in the gradient stress suppression zone 106. In other words, each set of second slots 105 is located in one of the gradient stress suppression regions 106, and each set of second slots 105 includes a plurality of second slot patterns 105a, 105b. In the present embodiment, the second groove pattern 105a, 105b is a groove that penetrates the film body 100. Further, in the present embodiment, the extending direction D1 of the first groove patterns 103a, 103b, 103c and the extending direction D2 of the second groove patterns 105a, 105b have an acute angle θ. The acute angle θ may be any angle less than 90 degrees, preferably 45 degrees. Further, according to the present embodiment, portions of the first groove patterns 103b, 103c are in contact with the adjacent second groove patterns 105a, 105b. Taking the embodiment of FIG. 1 as an example, the first groove pattern 103b is in contact with the second groove pattern 105b, and the first groove pattern 103c is in contact with the second groove pattern 105a of the other group of second grooves 105.

The plurality of connecting portions 108 are located between the second groove patterns 105a, 105b. In other words, each of the connecting portions 108 is located between the second slot patterns 105a, 105b of each of the second slots 105. The connecting portion 108 connects the film body 100 located in the gradient stress suppression region 106 with the film body 100 located in the central region 102 such that the film body 100 located in the gradient stress suppression region 106 and the film body 100 located in the central region 102 The structure becomes a continuous structure or an uninterrupted structure.

According to the film structure of FIG. 1 above, the first groove 103a, 103b, 103c is disposed in the side region 104, and the design corresponds to the structure in which the parallel spring 103' is formed in the side region 104 (as shown in FIG. 2). . Further, the second slits 105a, 105 and the connecting portion 108 are provided in the gradient stress suppressing region 106, and this design corresponds to the structure in which the spring body 105' is formed in the gradient stress suppressing region 106 (as shown in Fig. 2). Therefore, when the film body 100 is subjected to tensile stress, the parallel spring 103' and the spring body 105' can exert a function of dispersing tensile stress, thereby releasing tensile stress. Similarly, when the film body 100 is subjected to compressive stress, the parallel spring 103' and the spring body 105' can exert a function of dispersing compressive stress, thereby releasing compressive stress.

In particular, since the second slits 105a, 105b and the connecting portion 108 are provided in the gradient stress suppressing region 106, and the connecting portion 108 connects the film body 100 located in the gradient stress suppressing region 106 with the film located in the central region 102. The body 100 is configured to have a continuous structure or an uninterrupted structure between the film body 100 located in the gradient stress suppression region 106 and the film body 100 located in the central region 102. This design can suppress the gradient stress effect, so that the amount of rigid variation of the film body structure affected by the gradient stress is reduced. 3 is a gradient stress test curve of the film structure of the embodiment of FIG. 1, in which the X axis represents the gradient stress and the Y axis represents the resonance frequency. It can be seen from Fig. 3 that the film structure of Fig. 1 has a relatively small variation in the resonance frequency when subjected to different gradient stresses. In other words, when the film structure of Fig. 1 is subjected to different gradient stresses, the variation in structural rigidity is rather small.

In general, the design of conventional diaphragms has the problem of increasing the structural rigidity as the gradient stress increases. When the design of the diaphragm has an increase in structural rigidity as the gradient stress increases, the sensitivity of the film is lowered. However, since the film structure of the present invention suffers from different gradient stresses, the variation in structural rigidity is rather small. Therefore, the sensitivity of the film structure of the present invention is not easily reduced by the influence of the gradient stress.

The film structure of the embodiment of the above FIG. 1 is exemplified by a square film body, but the invention is not limited thereto. According to other embodiments, the film body can also have other shapes, such as circular or other polygonal shapes. 4 is a top view of a film structure in accordance with another embodiment. Referring to FIG. 4 , the film includes a film body 200 , a plurality of sets of first slots 203 , a plurality of sets of second slots 205 , and a plurality of connecting portions 208 .

The film body 200 has a central region 202, a plurality of side regions 204, and a plurality of gradient stress suppression regions 206. The side region 204 and the gradient stress suppression region 206 are located around the central region 202, and each gradient stress suppression region 206 is located between adjacent side edge regions 204.

A plurality of sets of first slots 203 are located in the side regions 204. In other words, each set of first slots 203 is correspondingly disposed in one of the side regions 204. In addition, each set of first slots 203 includes a plurality of staggered first slot patterns 203a, 203b, 203c, 203d, 203e. In the present embodiment, the first groove pattern 203a, 203b, 203c, 203d, 203e is a groove that penetrates the film body 200. Similarly, the present invention does not limit the number and length of the first slot patterns in each of the first slots, as long as the first slot patterns in each of the first slots are staggered with each other.

A plurality of sets of second slots 205 are located in the gradient stress suppression zone 206. In other words, each set of second slots 205 is located in one of the gradient stress suppression regions 206, and each set of second slots 205 includes a plurality of second slot patterns 205a, 205b. In the present embodiment, the second groove pattern 205a, 205b is a groove that penetrates the film body 200. Further, according to the present embodiment, a portion of the first groove pattern 203d, 203e is in contact with the adjacent second groove patterns 205a, 205b.

The plurality of connecting portions 208 are located between the second slot patterns 205a, 205b. In other words, each of the connecting portions 208 is located between the second slot patterns 205a, 205b of each of the second slots 205. The connecting portion 208 connects the film body 200 located in the gradient stress suppression region 206 with the film body 200 located in the central region 202 such that the film body 200 located in the gradient stress suppression region 206 and the film body 200 located in the central region 202 The structure becomes a continuous structure or an uninterrupted structure.

According to the film structure of FIG. 4 described above, the first slits 203a, 203b, 203c, 203d, 203e are provided in the side regions 204 to constitute a parallel spring structure. Further, the second slits 205a, 205b and the connecting portion 208 may be provided in the gradient stress suppression region 206 to constitute a spring body. Therefore, when the film body 200 is subjected to tensile stress or compressive stress, the parallel spring and the spring body can exert a tensile stress or a compressive stress, thereby releasing tensile stress or compressive stress. In addition, since the second slot 205a, 205b and the connecting portion 208 are disposed in the gradient stress suppression region 206, and the connecting portion 208 connects the film body 200 located in the gradient stress suppression region 206 with the film body located in the central region 202. 200, such that the film body 200 located in the gradient stress suppression region 206 and the film body 200 located in the central region 202 have a continuous structure or an uninterrupted structure. This design can suppress the gradient stress effect, so that the amount of rigid variation of the film body structure affected by the gradient stress is reduced.

The film structure design of the above FIG. 1 or FIG. 4 can be applied to a sound sensing device. 5A-5D are schematic diagrams showing a manufacturing process of a sound sensing device according to an embodiment of the invention. Referring first to FIG. 5A, a substrate 500 is first provided. The substrate 500 can be a tantalum substrate, such as a tantalum wafer. According to an embodiment of the present invention, the substrate 500 may be further formed with an isolation layer 502. The isolation layer 502 is, for example, a field oxide isolation layer or a shallow trench isolation layer.

Thereafter, a film 504 is formed on the isolation layer 502. According to an embodiment of the present invention, the material of the film 504 may be, for example, carbon-based polymers, silicon, silicon nitride, polycrystalline silicon, amorphous germanium (amorphous). Silicon), silicon dioxide, silicon carbide, and germanium, gallium, arsenide, carbon, titanium, gold , other metals such as iron, copper, chromium, tungsten, aluminum, platinum, nickel, tantalum, or alloys thereof. The film 504 described above may be a film structure as described in FIG. 1 or a film structure as shown in FIG. In other words, while the film 504 is being formed, the first groove pattern as described above is formed in the side regions of the film 504 by the semiconductor process, and the second groove pattern and the connection as described above are formed in the gradient stress suppression region. unit. Next, an interconnect layer 506 and a metal back plate 508 are formed on the film 504. The interconnect layer 506 has a plurality of interlayer dielectric layers and insulating layers and a plurality of wiring layers.

Referring to FIG. 5B, a first air chamber 501 is formed on the back surface of the substrate 500. The manner in which the first air chamber 501 is formed may be in a conventional etching manner. If the spacer layer 502 is formed on the substrate 500, the first air chamber 501 is formed in the substrate 500 and the spacer layer 502 as shown in FIG. 5C such that the surface of the film 504 is exposed. In other words, the first air chamber 501 penetrates the substrate 500 and the isolation layer 502.

Referring to FIG. 5D, a portion of the interconnect layer 506 (ie, the sacrificial layer within the interconnect layer 506) is removed to form a second air chamber 509 between the metal backplate 508 and the film 504. In other words, the second air chamber 509 extends through the interconnect layer 506 (i.e., the sacrificial layer within the interconnect layer 506), causing the structure of the film 504 to vacate, i.e., form a sound sensing device.

It is worth mentioning that, since the film 504 formed in the above step of FIG. 5A has the film design as described in FIG. 1 or FIG. 4, the stress generated by the process or the subsequent process after the film is performed may be It is a gradient stress effect that does not affect film 504. In other words, since the film 504 can release stress and the film properties are not affected by the gradient stress. Therefore, even after a plurality of processes, the uniformity of film characteristics at different positions on the wafer can be maintained.

The above embodiment of Figs. 5A to 5D is to apply the film structure of the present invention (for example, the film structure of Fig. 1 or Fig. 4) to a sound sensing device. However, the invention is not limited thereto. According to other embodiments, the film structure of the present invention (for example, the film structure of FIG. 1 or FIG. 4) can also be applied to other devices, such as a pressure gauge or other device having a diaphragm.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

100, 200. . . Film body

102, 202. . . Central area

104, 204. . . Side area

103, 203. . . First slot

103a~103c, 203a~203e. . . First slotted pattern

103’. . . Parallel spring

105, 205. . . Second slot

105a~103b, 205a~205b. . . Second slotted pattern

105’. . . Spring body

106, 206. . . Gradient stress suppression zone

108, 208. . . Connection

D1, D2. . . Extension direction

500. . . Substrate

501. . . First air chamber

502. . . Isolation layer

504. . . film

506. . . Inner layer

508. . . Metal backplane

509. . . Second air chamber

1 is a top plan view of a film structure in accordance with an embodiment of the present invention.

2 is a spring equivalent view of the film structure of the embodiment of FIG. 1.

3 is a gradient stress test curve of the film structure of the embodiment of FIG. 1.

4 is a top plan view of a film structure in accordance with another embodiment of the present invention.

5A-5D are schematic diagrams showing a manufacturing process of a sound sensing device according to an embodiment of the invention.

100. . . Film body

102. . . Central area

104. . . Side area

103. . . First slot

103a~103c. . . First slotted pattern

105. . . Second slot

105a~105b. . . Second slotted pattern

106. . . Gradient stress suppression zone

108. . . Connection

Claims (19)

A film structure comprising: a film body having a central region and a plurality of side regions around the central region and a plurality of gradient stress suppression regions, wherein each gradient stress suppression region is located on adjacent sides Between the regions; a plurality of sets of first slots, each set of first slots is located in one of the side regions, and each set of first slots includes a plurality of staggered first slot patterns; Slotting, each set of second slots is located in one of the gradient stress suppression zones, and each set of second slots includes a plurality of second slot patterns; and a plurality of connections, each of which is located in each group Between the second slotted patterns of the two slots and between each set of second slots and the central region to connect the film body located in the gradient stress suppression region with the film body located in the central region. The film structure of claim 1, wherein the film body has a square, a circle, a rectangle or a polygon. The film structure of claim 1, wherein the film body has a square or rectangular outline, and the film body has four side regions and four gradient stress suppression regions. The film structure of claim 3, wherein the gradient stress suppression zone is located at four corners of the film body. The film structure of claim 3, wherein the extending direction of the first groove pattern and the extending direction of the second groove patterns Has an acute angle. The film structure of claim 1, wherein each set of first slots has at least three first slot patterns, and the at least three first slot patterns are staggered. The film structure of claim 1, wherein a portion of the first groove patterns are adjacent to the adjacent second groove patterns. The film structure of claim 1, wherein the film body has a central region; and the first groove pattern and the second groove pattern around the central portion, wherein some of the portions The first slot pattern and the adjacent second slot patterns form a plurality of outer ring slot patterns, and the other portions of the first slot patterns form a plurality of inner ring slot patterns, and the inner rings are opened The groove pattern is located between the central region and the outer ring groove pattern, wherein the outer ring groove patterns have the same gap between the inner ring groove patterns, and the inner ring groove patterns have different gaps between the grooves. The film structure of claim 1, wherein the film body has a central region; and the first groove pattern and the second groove pattern around the central portion, wherein some of the portions The first groove pattern and the adjacent second groove patterns form a plurality of inner ring groove patterns, and the other portions of the first groove patterns form a plurality of outer ring groove patterns, and the inner rings are opened The groove pattern is located between the central region and the outer ring groove pattern, wherein the inner ring groove patterns have the same gap between the outer ring groove patterns, and the outer ring groove patterns have different gaps between the grooves. A sound sensing device structure comprising: a substrate; a film on the substrate, a first air chamber between a surface of the film and the substrate, wherein the film comprises: a film body, The film body has a central region and a plurality of side regions around the central region and a plurality of gradient stress suppression regions, wherein each gradient stress suppression region is located between adjacent side edge regions; and the plurality of sets of first slots, Each set of first slots is located in one of the side regions, and each set of first slots includes a plurality of staggered first slot patterns; and a plurality of sets of second slots, each set of second slots Located in one of the gradient stress suppression regions, and each set of second slots includes a plurality of second slot patterns; a plurality of connecting portions, each of the connecting portions being located in each of the second slots of the second slotted pattern Between the film body in the gradient stress suppression zone and the film body in the central region; and a metal backing plate over the film, wherein the metal back plate and the other surface of the film Have a second empty Chamber. The sound sensing device structure of claim 10, wherein the material of the film body comprises carbon-based polymers, silicon, silicon nitride, polycrystalline (polycrystalline) Silicon), amorphous silicon, silicon dioxide, silicon carbide, and germanium, gallium, arsenide, carbon, titanium Titanium), gold, iron, copper, chromium, Tungsten, aluminum, platinum, nickel, tantalum or alloys thereof. The sound sensing device structure of claim 10, further comprising an isolation layer between the substrate and the film, and the first air chamber penetrates the substrate and the isolation layer. The sound sensing device structure of claim 10, further comprising an interconnect layer between the film and the metal back plate, and the second air chamber extends through the interconnect layer. The sound sensing device structure of claim 10, wherein the film body has a contour of a square, a circle, a rectangle or a polygon. The sound sensing device structure of claim 10, wherein the film body has a square or rectangular outline, and the film body has four side regions and four gradient stress suppression regions. The sound sensing device structure of claim 15, wherein the gradient stress suppression zone is located at four corners of the film body. The sound sensing device structure of claim 15, wherein the extending direction of the first groove pattern has an acute angle with the extending direction of the second groove patterns. The sound sensing device structure of claim 10, wherein each set of first slots has at least three first slot patterns, and the at least three first slot patterns are staggered. The sound sensing device structure of claim 10, wherein a portion of the first slot patterns are in contact with the adjacent second slot patterns.