JP2006019589A - Semiconductor apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small and low cost semiconductor apparatus with a capacitance element and an electrical-signal-processing circuit integrated on an identical semiconductor substrate which can be manufactured over a wide range of capacitance value of the capacitance element. <P>SOLUTION: The semiconductor apparatus 100, 101 comprise a capacitance element (a humidity sensor element) 10 and the electrical-signal-processing circuit (a sensor-signal-processing circuit) using the capacitance element 10 formed on one surface side of the semiconductor substrate 1. The capacitance element 10 is formed on the semiconductor substrate 1 by a screen printing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor device in which a capacitive element and an electric signal processing circuit using the capacitive element are formed on one surface side of the same semiconductor substrate.

  A semiconductor device in which a capacitive element and an electric signal processing circuit using the capacitive element are formed on one surface side of the same semiconductor substrate is disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-243690 (Patent Document 1). ing.

  The semiconductor device disclosed in Patent Document 1 is a capacitive humidity sensor integrated on a single chip. The capacitive element is a humidity sensor element whose capacitance changes depending on humidity, and the electrical signal processing circuit includes the humidity sensor. It is a sensor signal processing circuit that performs electric signal processing on the capacitance change of the sensor element.

  FIG. 11 is a schematic cross-sectional view of a capacitive humidity sensor 90 disclosed in Patent Document 1. As shown in FIG.

  In the capacitive humidity sensor 90 of FIG. 11, a humidity sensor element and a sensor signal processing circuit are formed on one surface side of the semiconductor substrate 1.

  In the humidity sensor element forming portion, two electrodes 9a and 9b are formed on the silicon oxide film 2 formed on the semiconductor substrate 1 so as to be opposed to each other. The two electrodes 9a and 9b are made of the same aluminum (Al) metal layer as the wiring 9h of the sensor signal processing circuit protected by the silicon nitride film 3, and are separated so that the respective comb teeth mesh with each other and face each other. Thus, the electrodes are comb-like electrodes. The silicon nitride film 3 and the moisture sensitive film 4 are formed so as to cover the two electrodes 9a and 9b. The moisture sensitive film 4 is a dielectric film such as polyimide whose dielectric constant changes according to a change in humidity of the surrounding atmosphere. The moisture sensitive film 4 is formed on the entire surface of the semiconductor substrate 1 using spin coating and then formed by a patterning process including photolithography and etching.

The sensor signal processing circuit forming unit includes a reference capacitor (reference capacitor) forming unit and a CMOS transistor forming unit. The change in capacitance between the electrodes 9a and 9b in the humidity sensor element is compared with the reference capacitance, and is subjected to electrical signal processing in the CMOS transistor forming portion. As described above, the capacitive humidity sensor 90 of FIG. 11 measures the capacitance change between the electrodes 9a and 9b accompanying the humidity change, and measures the humidity of the atmosphere.
JP 2002-243690 A

  In the capacitive humidity sensor 90 shown in FIG. 11, a capacitive element as a humidity sensor element and an electric signal processing circuit as a sensor signal processing circuit are integrated on the same semiconductor substrate 1, and a miniaturized semiconductor device is obtained. It has become.

  However, the capacitive humidity sensor 90 shown in FIG. 11 has the following problems. First, the patterning process including photolithography and etching used for forming the capacitor element of the semiconductor device 90 is a process that requires a large manufacturing cost, and this hinders the cost reduction of the semiconductor device 90. Secondly, the comb-teeth capacitive element 90 can obtain only a small capacitance value compared to a laminated capacitive element in which a dielectric film is sandwiched between two electrodes. Third, since the semiconductor device 90 uses the silicon nitride film 3 which is a protective film for wiring as a constituent element of the capacitive element, this also reduces the capacitance value, and when a large capacitance value is required, the capacitive element is occupied. The area increases.

  SUMMARY OF THE INVENTION An object of the present invention is a semiconductor device in which a capacitive element and an electric signal processing circuit are integrated on the same semiconductor substrate, and can be manufactured in a small size and at low cost over a wide range of capacitance values in the capacitive element. To provide an apparatus. In particular, an object of the present invention is to provide the semiconductor device suitable for a capacitive humidity sensor.

  According to the first aspect of the present invention, a capacitive element including the first electrode, the second electrode, and a dielectric film, and an electric signal processing circuit using the capacitive element are formed on one surface side of the same semiconductor substrate. In the semiconductor device, at least one component of the first electrode, the second electrode, or the dielectric film, which is a component of the capacitive element, is formed on the semiconductor substrate by screen printing. It is characterized by.

  In the semiconductor device described above, at least one of the first electrode, the second electrode, and the dielectric film, which is a component of the capacitive element, uses a patterning process including photolithography and etching, which requires a large manufacturing cost. Without being formed by screen printing. For this reason, the semiconductor device can be manufactured at a lower cost than the conventional one, and a small and inexpensive semiconductor device in which the capacitor and the electric signal processing circuit are integrated on the same semiconductor substrate can be obtained. .

  According to a second aspect of the present invention, the capacitive element may be a stacked capacitive element in which the dielectric film is sandwiched between the lower first electrode and the upper second electrode.

  The laminated capacitive element can be a capacitive element having a large capacitance value despite a small occupation area. Therefore, by forming this multilayer capacitive element by screen printing as described above, the capacitive element having a large capacitance value and the electric signal processing circuit are integrated on the same semiconductor substrate, and can be manufactured in a small size and at low cost. The semiconductor device can be made.

  According to a third aspect of the present invention, in the stacked capacitive element, the lower first electrode is made of the same metal layer as the wiring of the electric signal processing circuit protected by a silicon nitride film, and the dielectric The body film and the second electrode can be a semiconductor device formed by screen printing.

  According to this, a special process for forming the first electrode of the capacitive element is not required, and the process can be shared with the wiring formation process of the electric signal processing circuit, so that the manufacturing cost of the semiconductor device is further reduced. can do.

  According to a fourth aspect of the present invention, in the laminated capacitive element, all of the first electrode, the dielectric film, and the second electrode can be formed by screen printing.

  In this case, as described in claim 5, the capacitive element can be disposed immediately above the electric signal processing circuit via an insulating film. Thereby, compared with the case where a capacitive element is arrange | positioned in the position different from the electric signal processing circuit formation part in a semiconductor substrate, the occupation area of the said semiconductor device whole can be made still smaller. In addition, since the capacitor element does not include a silicon nitride film, which is a protective film for the wiring, the capacitance of the first electrode is larger than that of a capacitor element made of the same metal layer as the wiring of the electric signal processing circuit. A capacitive element having a value can be obtained.

  According to another aspect of the present invention, in the semiconductor device, the capacitance element is a humidity sensor element whose capacitance changes depending on humidity, and the electric signal processing circuit detects the capacitance change of the humidity sensor element as an electric signal. It is suitable for a capacitive humidity sensor which is a sensor signal processing circuit to be processed.

  The capacitive humidity sensor measures a change in capacitance of a humidity sensor element accompanying a change in humidity using a sensor signal processing circuit. In order to improve the sensitivity of the humidity sensor element, it is preferable to have a large capacitance value. Further, a capacitive humidity sensor used in large numbers in vehicles and the like is required to be small and inexpensive. Therefore, the above-described semiconductor device in which the capacitive element has a large capacitance value and can be manufactured in a small size and at low cost is suitable for the capacitive humidity sensor.

  In using a semiconductor device in which a stacked capacitive element is formed as a capacitive humidity sensor, it is necessary that the second electrode in the upper layer has moisture permeability. For this purpose, for example, as described in claims 7 to 9, a second electrode having a plurality of through holes, a second electrode having a comb-tooth shape, or a second electrode made of a porous film having moisture permeability is used. It is preferable to use it.

  According to a tenth aspect of the present invention, the capacitive element includes a comb-teeth shape in which the capacitive element is disposed so as to be opposed to the dielectric film so that the respective comb teeth are engaged with each other on the same plane. A comb electrode type capacitive element including the first electrode and the second electrode can also be provided.

  A comb electrode type capacitive element is a capacitive element having a small capacitance value. However, since the first electrode and the second electrode can be formed at the same time, the capacitive element can be manufactured at a lower cost than a laminated capacitive element. Therefore, by forming the comb electrode type capacitive element by screen printing as described above, it can be manufactured at a lower cost, and the capacitive element having a small capacitance value and the electric signal processing circuit are the same semiconductor substrate. Thus, a small and very inexpensive semiconductor device can be obtained.

  In the comb electrode type capacitive element, for example, the first electrode and the second electrode are formed on the semiconductor substrate so as to cover the first electrode and the second electrode. Thus, a capacitive element in which the dielectric film is formed can be obtained.

  In this case, as described in claim 12, a protective film is formed on the first electrode and the second electrode, and the dielectric film is a capacitive element formed on the protective film. Can do. The protective film formed on the first electrode and the second electrode can suppress corrosion of the electrode even when the first electrode and the second electrode are exposed to a high humidity atmosphere, for example. A high semiconductor device can be obtained. The first electrode and the second electrode are made of the same metal layer as the wiring of the electric signal processing circuit protected by a silicon nitride film, and the dielectric film is formed by screen printing. In this way, a special process for forming the first electrode and the second electrode is not necessary. Thereby, the manufacturing cost of the semiconductor device can be further reduced.

  In the comb electrode type capacitive element, the dielectric film is formed on the semiconductor substrate, and the first electrode and the second electrode are formed on the dielectric film. A capacitor element formed can also be used. According to a fourteenth aspect of the present invention, the first electrode and the second electrode may be a capacitive element formed in the dielectric film formed on the semiconductor substrate. In this case, since both sides of the formation surface of the first electrode and the second electrode can be formed as a predetermined dielectric film, the capacitance value can be increased even in a comb electrode type capacitive element. it can.

  The first electrode, the second electrode, except for the case where the first electrode and the second electrode are made of the same metal layer as the wiring of the electric signal processing circuit protected by a silicon nitride film. The electrodes and the dielectric film are all preferably formed by screen printing.

  In this case, as described in claim 17, the capacitive element can be disposed immediately above the electric signal processing circuit via an insulating film. Thereby, compared with the case where a capacitive element is arrange | positioned in the position different from the electric signal processing circuit formation part in a semiconductor substrate, the occupation area of the said semiconductor device whole can be made small. In addition, since the capacitor element does not include a silicon nitride film that is a protective film for the wiring, as compared with a capacitor element in which the first electrode and the second electrode are made of the same metal layer as the wiring of the electric signal processing circuit. Thus, a capacitive element having a larger capacitance value can be obtained.

  The semiconductor device in which the comb electrode type capacitive element is formed by screen printing is manufactured in the same manner as the semiconductor device in which the stacked type capacitive element is formed. This is suitable for a capacitive humidity sensor.

  20. The semiconductor device according to claim 19, wherein the capacitive element is formed by screen printing, and the first electrode or the second electrode is provided through an opening of a protective film formed on the semiconductor substrate. It is preferable that the electric signal processing circuit is integrally connected to the wiring pad made of aluminum (Al) by screen printing. Thereby, it is possible to obtain a highly reliable electrical connection as compared with wire bonding or the like, and to reduce the manufacturing cost.

  As described above, when the first electrode or the second electrode is integrally connected to the wiring pad made of Al of the electric signal processing circuit by screen printing, it is exposed to the opening as described in claim 20. It is preferable to fill a conductive paste, which is a material of the first electrode or the second electrode, on the wiring pad to be formed. In addition, as described in claim 21, the protective film and the wiring pad may be planarized. As a result, the step difference between the wiring pads exposed on the top surface of the opening and the bottom surface of the opening can be reduced, so that more reliable connection can be obtained.

  In addition, in order to improve the adhesion of the wiring pad with Al and reduce the connection resistance, a gold (Au) layer is formed on the wiring pad exposed in the opening as described in claim 22. The first electrode or the second electrode may be connected to the wiring pad made of Al via the Au layer.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1A is an example of a semiconductor device of the present invention in which a capacitive element and an electric signal processing circuit are formed on one surface side of the same semiconductor substrate. is there. In the capacitive humidity sensor 100 of FIG. 1A, the same reference numerals are given to the same parts as those of the conventional capacitive humidity sensor 90 shown in FIG.

  In the semiconductor device 100 that is the capacitive humidity sensor of FIG. 1A, a humidity sensor element 10 whose capacity changes with humidity is formed on one surface side of the semiconductor substrate 1 as a capacitive element. Further, on the same side of the semiconductor substrate 1 as the humidity sensor element 10, a sensor signal processing circuit composed of a reference capacitor, a CMOS transistor, or the like is formed as an electric signal processing circuit. ing.

  In the capacitive humidity sensor 100 of FIG. 1A, the capacitive element 10 which is a humidity sensor element is composed of the silicon oxide film 2 and the silicon nitride film 3 on the semiconductor substrate 1 at a position different from the sensor signal processing circuit forming portion. It arrange | positions on a laminated film. The silicon oxide film 2 is an interlayer insulating film of the wiring 10h made of an aluminum (Al) metal layer in the sensor signal processing circuit forming portion, and the silicon nitride film 3 is a protective film of the wiring 10h.

  A capacitive element 10 shown in FIG. 1A is a stacked capacitive element in which a dielectric film 4 is sandwiched between a lower first electrode 10a and an upper second electrode 10b. The laminated capacitive element 10 can be a capacitive element having a large capacitance value despite its small occupation area. The dielectric film 4 of the capacitive element 10 that is a humidity sensor element is a moisture-sensitive film made of polyimide whose dielectric constant changes according to the humidity change of the surrounding atmosphere.

  In the laminated capacitive element 10 of FIG. 1A, all of the first electrode 10a, the dielectric film 4 and the second electrode 10b are formed by screen printing. Therefore, unlike the conventional capacitive humidity sensor 90 shown in FIG. 11, a patterning process consisting of photolithography and etching, which requires a large manufacturing cost, is not used. Therefore, the capacitive humidity sensor 100 of FIG. 1A can be manufactured at a lower cost than the conventional one, and the laminated humidity sensor element 10 having a large capacitance value and the sensor signal processing circuit are the same semiconductor. A small and inexpensive capacitive humidity sensor integrated on the substrate 1 can be obtained.

  FIG. 1B is a schematic cross-sectional view of a capacitive humidity sensor 101 as an example of another semiconductor device having a stacked capacitive element 10.

  In the capacitive humidity sensor 101 of FIG. 1B, the capacitive element 10 which is a humidity sensor element is arranged directly above the sensor signal processing circuit through an insulating film made of the silicon nitride film 3. For this reason, the capacitive humidity sensor 101 in FIG. 1B occupies the entire area as compared with the capacitive humidity sensor 100 in FIG. 1A in which the capacitive element 10 is arranged at a position different from the sensor signal processing circuit forming unit. The area can be reduced.

  FIG. 2 is a schematic cross-sectional view of a capacitive humidity sensor 110 as an example of a semiconductor device having another laminated capacitive element 11.

  2 is the same as the wiring 10h of the sensor signal processing circuit in which the lower first electrode 11a is protected by the silicon nitride film 3, and is made of an aluminum (Al) metal layer. Become. The dielectric film 4 and the second electrode 10b are formed by screen printing in the same manner as the capacitive element 10 shown in FIGS.

  The capacitive humidity sensor 110 of FIG. 2 does not require a special process for forming the first electrode 11a of the capacitive element 11, and can be shared with the process of forming the wiring 10h of the sensor signal processing circuit. Compared to the capacitive humidity sensors 100 and 101 of (a) and (b), the manufacturing cost can be reduced. In addition, since the formation of the first electrode 11a is shared with the process of forming the wiring 10h of the sensor signal processing circuit, in the capacitive humidity sensor 110 of FIG. 2, the silicon nitride film 3 that is a protective film of the wiring 10h is inevitably As a dielectric film, it becomes a constituent element of the capacitive element 11. On the other hand, in the capacitive humidity sensors 100 and 101 of FIGS. 1A and 1B, since the capacitive element 10 does not include the silicon nitride film 3 which is a protective film of the wiring 10h, the thickness of the dielectric film 4 is increased. Are the same as the capacitive element 11 in the capacitive humidity sensor 110 of FIG. 2, the capacitive element can have a larger capacitance value.

  Since the laminated capacitive elements 10 and 11 shown in FIGS. 1A and 1B and FIG. 2 are humidity sensor elements in the capacitive humidity sensors 100, 101, and 110, the upper second electrode 10b is moisture permeable. It is necessary to have 3A to 3C show examples of the second electrode having moisture permeability. FIG. 3A is a top view of the second electrode 10bh having a plurality of through holes h. FIG. 3B is a top view of the second electrode 10bk having a comb shape. FIG. 3C is a top view of the second electrode 10 bp made of a porous film having moisture permeability. The second electrode 10bp in FIG. 3C can be formed, for example, by mixing a large amount of resin component that volatilizes during baking into the conductive paste. If the second electrodes shown in FIGS. 3A to 3C are used, water molecules as humidity components are passed through the dielectric film 4 through the through holes h, the gaps between the comb teeth, or the holes formed in the film. Can be adsorbed or desorbed quickly.

  The semiconductor devices 100, 101, and 110 shown in FIGS. 1A, 1B, and 2 are semiconductor devices in which the stacked capacitive elements 10 and 11 are formed by screen printing. Next, an example of a semiconductor device in which another type of capacitor element is formed by screen printing will be described.

  4A is a schematic cross-sectional view of the semiconductor device 120 that is a capacitive humidity sensor, and FIG. 4B is a schematic view of the capacitive element 12 that is a humidity sensor element formed in the semiconductor device 120. FIG. In the semiconductor device 120 shown in FIG. 4A, the same reference numerals are given to the same parts as those of the semiconductor device 100 shown in FIG.

  As shown in FIGS. 4A and 4B, the capacitive element 12 in the semiconductor device 120 is opposed to the dielectric film 4 that is a moisture-sensitive film made of polyimide, with the comb teeth meshing with each other on the same plane. This is a comb-shaped electrode type capacitive element including a comb-shaped first electrode 12a and a second electrode 12b that are spaced apart from each other. In the comb electrode type capacitive element 12 in the semiconductor device 120 of FIGS. 4A and 4B, the first electrode 12 a and the second electrode 12 b are composed of the silicon oxide film 2 and the silicon nitride film 3 on the semiconductor substrate 1. A dielectric film 4 is formed on the laminated film so as to cover the first electrode 12a and the second electrode 12b. The first electrode 12a, the second electrode 12b, and the dielectric film 4 are all formed by screen printing.

  Although the comb electrode type capacitive element 12 is a capacitive element having a smaller capacitance value than the multilayer capacitive element, the first electrode 12a and the second electrode 12b can be formed at the same time. Compared to, it can be manufactured at a low cost. Therefore, by forming the comb-teeth electrode type capacitive element 12 by screen printing as described above, it can be manufactured at a lower cost, and the capacitive element 12 having a small capacitance value and the electric signal processing circuit are the same. A small and very inexpensive semiconductor device integrated on the semiconductor substrate 1 can be obtained.

  FIG. 5 is a schematic cross-sectional view of a capacitive humidity sensor 121 as an example of another semiconductor device having a comb-teeth-type capacitive element 12.

  In the capacitive humidity sensor 121 of FIG. 5, as in the capacitive humidity sensor 101 of FIG. 1B, the capacitive element 12 that is a humidity sensor element is subjected to sensor signal processing via an insulating film made of the silicon nitride film 3. It is placed directly above the circuit. Therefore, the capacitive humidity sensor 121 of FIG. 5 has a smaller occupied area than the capacitive humidity sensor 120 of FIG. 4A in which the capacitive element 12 is arranged at a position different from the sensor signal processing circuit forming unit. can do. In the capacitive humidity sensor 121 of FIG. 5, the silicon nitride film 3 on the sensor signal processing circuit is flattened to stabilize the capacitance value of the capacitive element 12.

  FIGS. 6 to 8 are examples of semiconductor devices having other comb-teeth-type capacitive elements, and are schematic diagrams of capacitive humidity sensors 130, 140, and 150 in which comb-teeth-type capacitive elements 13 to 15 are formed, respectively. FIG.

  In the capacitive element 13 of the capacitive humidity sensor 130 shown in FIG. 6, unlike the comb electrode capacitive element 12 shown in FIGS. 4 and 5, a protective film 4c is formed on the first electrode 12a and the second electrode 12b. A moisture sensitive dielectric film 4 made of polyimide is formed on the protective film 4c. The protective film 4c formed on the first electrode and the second electrode can suppress the corrosion of the electrode even when the first electrode 12a and the second electrode 12b are exposed to a high humidity atmosphere. A highly reliable semiconductor device can be obtained. On the other hand, in the comb electrode type capacitive element 12 shown in FIGS. 4 and 5, the protective film 4c shown in FIG. 6 is not provided, and the silicon nitride film 3 which is the protective film of the wiring 10h is not a constituent element of the capacitive element. As compared with the capacitive element of FIG. 6 or the capacitive element in which the first electrode and the second electrode are made of the same metal layer as the wiring of the electric signal processing circuit, the capacitive element can have a larger capacitance value.

  In the capacitive element 14 of the capacitive humidity sensor 140 shown in FIG. 7, unlike the comb-teeth-type capacitive elements 12 and 13 shown in FIGS. 4 to 6, the first electrode 14 a and the second electrode 14 b are formed on the semiconductor substrate 1 ( The film is formed on a dielectric film 4 formed on a silicon oxide film 2 and a silicon nitride film 3.

  Further, in the capacitive element 15 of the capacitive humidity sensor 150 shown in FIG. 8A, the first electrode 15a and the second electrode 15b are on the semiconductor substrate 1 (a laminated film composed of the silicon oxide film 2 and the silicon nitride film 3). It is formed in the dielectric film 4 formed in the above. In this case, as shown in FIG. 8 (b), since both sides of the formation surface of the first electrode 15a and the second electrode 15b can be the predetermined dielectric film 4, the comb shown in FIGS. Compared with the toothed electrode type capacitive element 12, a capacitive element having a capacitance value about twice as large can be obtained.

  Next, a connection structure of the first electrode and the second electrode to the electric signal processing circuit in the semiconductor device of the present invention will be described.

  FIGS. 9A and 9B are examples of the connection structure. FIG. 9A is a top view of the capacitor element 16 forming portion in the semiconductor device 160, and FIG. 9B is a cross-sectional view taken along line AA in FIG. 9A.

  In the semiconductor device 160 shown in FIGS. 9A and 9B, the first electrode 16a and the second electrode 16b in the capacitive element 16 are electrically connected to each other through the opening of the silicon nitride film 3 that is a wiring protective film. The signal processing circuit is integrally connected to the wiring pads 10ha and 10hb by screen printing. Thereby, it is possible to obtain a highly reliable electrical connection as compared with wire bonding or the like, and to reduce the manufacturing cost. The capacitive element 16 shown in FIGS. 9A and 9B is a laminated capacitive element, but the first electrode and the second electrode in the comb electrode capacitive element are connected to the electric signal processing circuit. Can be formed similarly.

  FIGS. 10A to 10C are examples of other connection structures, and are schematic cross-sectional views of the connection portion between the electrode wiring of the capacitive element and the wiring pad of the electric signal processing circuit, respectively.

  In the semiconductor device 170 shown in FIG. 10A, a conductive paste 17d as an electrode material is filled in advance on the wiring pad 10hc exposed in the opening of the silicon nitride film 3, and the filled conductive paste 17d The electrode wiring 17c of the capacitive element is integrally connected by screen printing. In the semiconductor device 170 of FIG. 10A, the step between the wiring pad 10hc exposed on the upper surface of the opening of the silicon nitride film 3 and the bottom surface of the opening can be reduced by the pre-filled conductive paste 17d. The disconnection failure is suppressed, and more reliable connection can be obtained as compared with the semiconductor device 160 shown in FIGS.

  In the semiconductor device 180 shown in FIG. 10B, the silicon nitride film 3 as a protective film and the wiring pad 10hc are polished and planarized in advance, and the planarized silicon nitride film 3 and the wiring pad 10hc are formed on the planarized silicon nitride film 3 and the wiring pad 10hc. The electrode wiring 18c of the capacitive element is integrally connected by screen printing. This also eliminates the step around the opening of the silicon nitride film 3, thereby preventing the step failure of the electrode wiring 18c and providing a reliable connection.

  In the semiconductor device 190 shown in FIG. 10C, a gold (Au) layer 5h is formed on the wiring pad 10hc made of aluminum (Al) exposed in the opening of the silicon nitride film 3, and the Au layer 5h is interposed therebetween. The electrode wiring 19c of the capacitive element is integrally connected by screen printing. Thereby, the adhesiveness between the electrode wiring 19c and the wiring pad 10hc is improved, and the connection resistance between the electrode wiring 19c and the wiring pad 10hc can be reduced.

  The semiconductor device of the present invention has been described above by taking the capacitive humidity sensor as an example. The capacitive humidity sensor measures a change in capacitance of a humidity sensor element accompanying a change in humidity using a sensor signal processing circuit. In order to improve the sensitivity of the humidity sensor element, a laminated capacitive element having a large capacitance value is preferable. However, even in the case of a comb electrode type capacitive element, for example, a predetermined dielectric film can be arranged on both sides of the electrode as in the capacitive element 15 shown in FIG. Further, a capacitive humidity sensor used in large numbers in vehicles and the like is required to be small and inexpensive. Therefore, the semiconductor device of the present invention, which has a large capacitance value and can be manufactured in a small size and at a low cost, is suitable for a capacitive humidity sensor. However, the semiconductor device of the present invention in which the capacitive element is formed by screen printing is not limited to the capacitive humidity sensor, and an arbitrary one in which the capacitive element and the electric signal processing circuit are formed on one surface side of the same semiconductor substrate. It can be applied to the semiconductor device.

  As described above, the semiconductor device of the present invention is a semiconductor device in which the capacitor element and the electric signal processing circuit are integrated on the same semiconductor substrate, and is small and low over a wide range of capacitance values in the capacitor element. The semiconductor device can be manufactured at low cost, and is particularly suitable for a capacitive humidity sensor.

(A) is an example of the semiconductor device of this invention, and is typical sectional drawing of a capacitive humidity sensor. (B) is an example of another semiconductor device having a laminated capacitive element, and is a schematic cross-sectional view of a capacitive humidity sensor. FIG. 6 is a schematic cross-sectional view of a capacitive humidity sensor as an example of a semiconductor device having another stacked capacitive element. (A)-(c) is an example of the 2nd electrode which has moisture permeability, and is a top view of each 2nd electrode. In another example of the semiconductor device according to the present invention, (a) is a schematic cross-sectional view of a semiconductor device which is a capacitive humidity sensor, and (b) is a capacitive element which is a humidity sensor element formed in the semiconductor device. FIG. FIG. 6 is a schematic cross-sectional view of a capacitive humidity sensor as an example of another semiconductor device having a comb electrode type capacitive element. FIG. 6 is a schematic cross-sectional view of a capacitive humidity sensor as an example of a semiconductor device having another comb electrode capacitive element. FIG. 6 is a schematic cross-sectional view of a capacitive humidity sensor as an example of a semiconductor device having another comb electrode capacitive element. FIG. 5 is an example of a semiconductor device having another comb-teeth electrode type capacitive element, where (a) is a schematic cross-sectional view of a capacitive humidity sensor, and (b) is a capacitance value of the capacitive element formed in the semiconductor device. FIG. 2A and 2B are diagrams illustrating a connection structure of a first electrode and a second electrode to an electric signal processing circuit in a semiconductor device of the present invention, wherein FIG. It is AA sectional drawing in a). (A)-(c) is an example of another connection structure, and is respectively typical sectional drawing of the connection part of the electrode wiring of a capacitive element, and the wiring pad of an electric signal processing circuit. It is typical sectional drawing of the conventional capacitive humidity sensor.

Explanation of symbols

90, 100, 101, 110, 120, 121, 130, 140, 150, 160, 170, 180, 190 Semiconductor device (capacitive humidity sensor)
DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 2 Silicon oxide film 3 Silicon nitride film 4 Dielectric film (humidity sensitive film)
4c Protective film 10-16 Capacitance element (humidity sensor element)
10a, 11a, 12a to 16a First electrode 10b, 10bh, 10bk, 10bp, 12b to 16b Second electrode 10h Wiring 10ha, 10hb, 10hc Wiring pad 17c to 19c Electrode wiring 17d Conductive paste 5h Gold (Au) layer

Claims (22)

A capacitive device composed of a first electrode, a second electrode and a dielectric film, and an electric signal processing circuit using the capacitive element are formed on one surface side of the same semiconductor substrate,
A semiconductor device, wherein at least one of the first electrode, the second electrode, and the dielectric film, which are components of the capacitive element, is formed on the semiconductor substrate by screen printing.   2. The semiconductor device according to claim 1, wherein the capacitive element is a stacked capacitive element in which the dielectric film is sandwiched between the lower first electrode and the upper second electrode. . The first electrode is made of the same metal layer as the wiring of the electric signal processing circuit protected by a silicon nitride film,
The semiconductor device according to claim 2, wherein the dielectric film and the second electrode are formed by screen printing.   The semiconductor device according to claim 2, wherein the first electrode, the dielectric film, and the second electrode are formed by screen printing.   The semiconductor device according to claim 4, wherein the capacitive element is disposed immediately above the electric signal processing circuit via an insulating film. The capacitive element is a humidity sensor element whose capacitance changes with humidity,
6. The semiconductor device according to claim 2, wherein the electrical signal processing circuit is a sensor signal processing circuit that performs electrical signal processing on a capacitance change of the humidity sensor element.   The semiconductor device according to claim 6, wherein the second electrode has a plurality of through holes.   The semiconductor device according to claim 6, wherein the second electrode has a comb shape.   The semiconductor device according to claim 6, wherein the second electrode is made of a porous film having moisture permeability.   The capacitive element includes a comb-teeth electrode including the dielectric film and the comb-shaped first electrode and the second electrode arranged so as to face each other so that the comb teeth mesh with each other on the same plane. The semiconductor device according to claim 1, wherein the semiconductor device is a type capacitive element.   The said 1st electrode and 2nd electrode are formed on the said semiconductor substrate, The said dielectric film is formed so that the said 1st electrode and 2nd electrode may be covered, The 10th aspect is characterized by the above-mentioned. The semiconductor device described.   The semiconductor device according to claim 11, wherein a protective film is formed on the first electrode and the second electrode, and the dielectric film is formed on the protective film.   11. The semiconductor device according to claim 10, wherein the dielectric film is formed on the semiconductor substrate, and the first electrode and the second electrode are formed on the dielectric film.   The semiconductor device according to claim 10, wherein the first electrode and the second electrode are formed in the dielectric film formed on the semiconductor substrate. The first electrode and the second electrode are made of the same metal layer as the wiring of the electric signal processing circuit protected by a silicon nitride film,
The semiconductor device according to claim 12, wherein the dielectric film is formed by screen printing.   15. The semiconductor device according to claim 10, wherein the first electrode, the second electrode, and the dielectric film are formed by screen printing.   The semiconductor device according to claim 16, wherein the capacitive element is disposed immediately above the electric signal processing circuit with an insulating film interposed therebetween. The capacitive element is a humidity sensor element whose capacitance changes with humidity,
18. The semiconductor device according to claim 10, wherein the electrical signal processing circuit is a sensor signal processing circuit that performs electrical signal processing on a capacitance change of the humidity sensor element. The first electrode or the second electrode is
2. The wiring board made of aluminum (Al) of the electric signal processing circuit is integrally connected by screen printing through an opening of a protective film formed on the semiconductor substrate. The semiconductor device according to any one of 2 to 18.   The semiconductor device according to claim 19, wherein a conductive paste which is a material of the first electrode or the second electrode is filled on the wiring pad exposed in the opening.   The semiconductor device according to claim 19, wherein the protective film and the wiring pad are planarized. A gold (Au) layer is formed on the wiring pad exposed in the opening,
The semiconductor device according to claim 19, wherein the first electrode or the second electrode is connected to the wiring pad made of Al through the Au layer.

Images