JP5685060B2 - Semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor device having a plurality of element regions.

  In order to protect the circuit formation region of the semiconductor device from the influence of moisture and ions from the ambient atmosphere, a protective structure called a seal ring is provided inside the dicing line, that is, near the edge portion of the chip (die). The seal ring is formed by a wiring layer (Cu) and a contact similar to the circuit formation region, and is formed so as to surround the circuit formation region of the semiconductor device.

  Further, the seal ring also has an action of suppressing the occurrence of cracks in the circuit forming region when dicing the dicing region. During dicing, cracks may occur in the dicing area. However, since a seal ring exists between the dicing area and the circuit formation area, the crack is suppressed from reaching the circuit formation area.

  Further, a protective film called a passivation film is provided on the surface as means for protecting the surface of the semiconductor device and avoiding the influence of the external atmosphere.

  As a conventional semiconductor device having a seal ring, there is a technique described in Patent Document 1. Patent Document 1 describes a semiconductor device having a seal ring and a passivation film covering an upper surface thereof.

JP 2004-79596 A JP 2002-270608 A

  However, as a result of examination by the present inventor, when a seal ring is provided in a device in which a logic circuit formation region (logic portion) and an analog circuit formation region (analog portion) are mixed, the seal portion is provided in the analog portion. It became clear that the device might malfunction. Therefore, this cause was examined using the apparatus having the configuration shown in FIGS. FIG. 11 is a plan view showing a configuration of a semiconductor device having a seal ring. 12 is an enlarged cross-sectional view (II ′ cross-sectional view) of a region (seal ring region 206) where the seal ring is formed in FIG.

  As shown in FIGS. 11 and 12, in the semiconductor chip 200, the seal ring region 206 is formed inside the dicing line 203 of the silicon substrate 201, and a circuit formation region (internal circuit) is formed on the left side in FIG. A dicing area exists on the right side of the area 207). The seal ring region 206 is provided closer to the dicing region than the internal circuit region 207.

  Also, as shown in FIG. 12, the semiconductor chip 200 is formed on the silicon substrate 201 with an interlayer insulating film 223, an interlayer insulating film 227, an interlayer insulating film 231, an interlayer insulating film 235, an interlayer insulating film 239, and an interlayer insulating film 243. , And a passivation film 247 are stacked in this order. The silicon substrate 201 has an n well 211 and a p well 209 adjacent to each other in the vicinity of the surface. The p well 209 is formed from the internal circuit region 207 to the seal ring region 206.

In the internal circuit region 207, a gate oxide film 217 and a gate electrode 219 are stacked in this order on the surface of the silicon substrate 201 provided with the n-well 211. A p ⁺ diffusion layer 213 functioning as a source / drain region and an n ⁺ diffusion layer 215 are provided in a region above the n well 211 of the silicon substrate 201. A gate oxide film 217 and a gate electrode 219 are also stacked in this order on the p well 209. An n ⁺ diffusion layer 215 functioning as a source / drain region and a p ⁺ diffusion layer 213 are provided in a region above the p well 209 of the silicon substrate 201. The p ⁺ diffusion layer 213, the n ⁺ diffusion layer 215, and the gate electrode 219 are connected to the connection plug 224. The outer periphery of the side surfaces of the p ⁺ diffusion layer 213 and the n ⁺ diffusion layer 215 is insulated by the element isolation film 221. The connection plug 224 is a conductive plug embedded in the interlayer insulating film 223 and penetrating through the interlayer insulating film 223, and its upper surface is connected to a wiring 226 embedded in the interlayer insulating film 227.

In the seal ring region 206, a p ⁺ diffusion layer 213 is formed in the vicinity of the surface of the silicon substrate 201 in contact with the upper surface of the p well 209 of the silicon substrate 201. The surface of the p ⁺ diffusion layer 213 is connected to the lower surface of the conductive ring 225 embedded in the interlayer insulating film 223 and penetrating therethrough. From the conductive ring 225 toward the upper layer, the conductive ring 229, the conductive ring 233, the conductive ring 237, the conductive ring 241 and the conductive ring 245 are connected in this order. Conductive ring 229, conductive ring 233, conductive ring 237, conductive ring 241 and conductive ring 245 are embedded in interlayer insulating film 227, interlayer insulating film 231, interlayer insulating film 235, interlayer insulating film 239 and interlayer insulating film 243, respectively. Through the insulating film. The seal ring 205 includes conductive rings 225 to 245. In FIG. 12, a triple seal ring 205 is provided.

  As a result of a detailed examination of the operation of the semiconductor chip 200 by the present inventor, it became clear that noise generated in the digital unit 251 propagates to the analog unit 253 through the seal ring 205 as shown in FIG. . FIG. 13 is a plan view showing a noise propagation path. According to the study by the present inventor, in the same figure, it is clear that the propagation of noise to the analog unit 253 via the seal ring 205 causes the malfunction of the element provided in the analog unit 253. became.

The present invention has been made on the basis of the above-described new knowledge by the present inventor, and suppresses noise propagation by providing a non-conducting portion in the guard ring formation region.
That is, according to the present invention,
A semiconductor device having first and second element regions,
A semiconductor substrate;
An interlayer insulating film provided on the semiconductor substrate;
An annular guard ring that is formed of a conductive film embedded in the interlayer insulating film and surrounds the outer periphery of the first element region;
Have
A semiconductor device characterized in that a non-conductive portion for blocking conduction of a path from the first element region to the second element region via the guard ring is provided in the guard ring formation region. Provided.

  In this specification, the “guard ring” refers to an annular conductive member that surrounds at least one element region. The guard ring can be a member provided along the periphery (dicing line) of the semiconductor substrate such as a seal ring, but may not necessarily be provided along the dicing line. A member surrounding the first element region provided in the center of the semiconductor substrate, and the second element region may be provided closer to the dicing line than the guard ring. The planar shape of the guard ring is not limited to a completely closed ring, but a shape in which a part of the ring is missing or a structure in which a part of the ring is separated by an interlayer insulating film Is also included.

  In the present specification, the “guard ring forming region” refers to an annular region including the guard ring in a plan view, regardless of whether the guard ring is completely annular. In addition to the guard ring, this region includes, for example, a semiconductor substrate and an interlayer insulating film provided on the semiconductor substrate.

  Further, in this specification, the “non-conducting portion” is provided in the guard ring forming region, and is configured to block the conduction of the path from the first element region to the second element region via the guard ring. This is a portion that makes the one region and the second region non-conductive. Specific examples of the non-conductive portion include (i) an insulating region provided in the path, and (ii) a pn junction surface provided in the path.

In general, the impedance Z in a certain region is represented by the following formula (1).
Z = R + j (ωL−1 / ωC) (1)
(In the above formula (1), ω is frequency, R is electrical resistance, L is self-inductance, and C is capacitance.)
The non-conductive portion in the present invention is that the impedance represented by the above formula (1) is sufficiently high, and noise generated in one of the first element region and the second element region propagates to the other. It has a function of suppressing it to such a level that there is no practical problem. Specific examples of such a non-conductive portion include (i) the insulating region provided in the path, (ii) the pn junction surface provided in the path, and the like. (I) increases Z by increasing R in equation (1), and (ii) increases Z by decreasing C in equation (1). It should be noted that the interruption of conduction by the non-conduction part is sufficient as long as noise propagation can be reduced to a desired level or less, and even if a minute current flows as long as noise propagation is not caused. Good.

  As an example of the above (i), in the region where the non-conductive portion is provided, the semiconductor substrate and the guard ring are separated by an insulating film, and the insulating film constitutes the non-conductive portion, and the non-conductive portion is A configuration in which the guard ring is connected to the semiconductor substrate in a region other than the provided region can be given. In this configuration, the non-conducting portion constituted by the insulating film has a large R in the above formula (1) and can block conduction.

  On the other hand, as an example of the above (ii), a diffusion layer having a conductivity type opposite to the conductivity type of the semiconductor substrate is provided in the vicinity of the surface of the semiconductor substrate, and the surface of the semiconductor substrate in the region where the diffusion layer having the opposite conductivity type is provided. A mode in which the guard ring is connected and the joint surface of the diffusion layer forms a non-conducting portion can be mentioned. At this time, Z can be suitably increased by reducing the size of C from the above formula (1). For this reason, it is possible to effectively suppress the propagation of noise between the first element region and the second element region. In addition, there is no restriction | limiting in particular about the impurity concentration profile of the diffusion layer of opposite conductivity type, The thing of a various aspect is employable.

  The mode (ii) is particularly effective when an analog circuit element and a digital circuit element are formed in one of the first element region and the second element region. In such a configuration, when noise generated in the digital circuit element propagates through the path, the impedance Z can be suitably increased by effectively reducing the total of the capacitances C in the path. This effect is remarkably exhibited when ω is small in the above formula (1), and propagation of low frequency noise can be effectively suppressed.

  As described above, the present inventor has found that noise generated in a predetermined element region propagates to another element region via a guard ring such as a seal ring, thereby causing an element provided in the other element region to malfunction. It has been found that this may occur. In the present invention, a non-conducting portion is provided in the guard ring formation region. The non-conducting part cuts off the conduction of the path from the first element region to the second element region via the guard ring, thereby reliably suppressing noise propagation between the first and second element regions. be able to.

  According to the present invention, it is possible to effectively suppress noise propagation through a guard ring interposed between two element regions.

It is a top view which shows the structure of the semiconductor device which concerns on a reference example . It is II 'sectional drawing of FIG. It is II-II 'sectional drawing of FIG. It is sectional drawing which shows the structure of the semiconductor device which concerns on a reference example . It is sectional drawing which shows the structure of the semiconductor device which concerns on this embodiment. It is a top view which shows the structure of the semiconductor device which concerns on a reference example . It is II 'sectional drawing of FIG. It is sectional drawing which shows the structure of the semiconductor device which concerns on a reference example . It is a top view which shows the structure of the semiconductor device which concerns on a reference example . It is a top view which shows the structure of the semiconductor device which concerns on a reference example . It is a top view which shows the structure of a semiconductor device. It is II 'sectional drawing of FIG. It is a top view which shows the structure of a semiconductor device.

Hereinafter, reference examples and embodiments of the present invention will be described with reference to the drawings. In all the drawings, common constituent elements are denoted by the same reference numerals, and description thereof is omitted as appropriate. In the following reference examples and embodiments, the case where the guard ring is a seal ring provided along the periphery of the semiconductor substrate will be mainly described as an example, but the present invention is not limited to this, and the guard ring is not limited thereto. The ring can be provided in any region on the element formation surface of the substrate. This point will be described later with reference to FIG.

(First reference example )
FIG. 1 is a plan view showing the configuration of the semiconductor chip of this reference example . The semiconductor chip 100 shown in FIG. 1 has two element regions of a logic part 151 (region A) and an analog unit 153 (region B) on a silicon substrate 101. In addition, the semiconductor chip 100 is provided with an annular seal ring region 106 surrounding these element regions along the dicing surface 103. Hereinafter, the case where the seal ring 105 (FIGS. 2 and 3) provided in the seal ring region 106 is formed of a triple annular conductive plug will be described as an example.

  2 is a cross-sectional view taken along the line II ′ of FIG. 1, and FIG. 3 is a cross-sectional view taken along the line II-II ′ of FIG. 2 and 3 are diagrams showing the configuration of the seal ring region 106 and the internal circuit adjacent thereto, respectively.

1-3 is a semiconductor device having first and second element regions (logic unit 151 and analog unit 153), and includes a semiconductor substrate (silicon substrate 101) and a semiconductor substrate. Provided interlayer insulating films (first insulating film 123, second insulating film 127, third insulating film 131, fourth insulating film 135, fifth insulating film 139, and sixth insulating film 143), and in the interlayer insulating film (First conductive ring 125, second conductive ring 129, third conductive ring 133, fourth conductive ring 137, fifth conductive ring 141, and sixth conductive ring 145).
The semiconductor chip 100 has an annular guard ring (seal ring 105) that surrounds the outer periphery of the logic unit 151 or the analog unit 153, and interrupts conduction of a path from the logic unit 151 to the analog unit 153 via the seal ring 105. The non-conductive portion 104 is provided in the guard ring formation region (seal ring region 106). In this reference example , the seal ring 105 surrounds the outer periphery of both the logic unit 151 and the analog unit 153.
The seal ring 105 is provided along the periphery of the silicon substrate 101 and surrounds the outer periphery of the logic unit 151 and the analog unit 153. In addition, the seal ring 105 includes multiple ring-shaped conductive films that are adjacent to each other along the periphery of the silicon substrate 101 with an interlayer insulating film interposed therebetween.
The non-conduction part 104 is provided close to the logic part 151 or the analog part 153. In this reference example , the seal ring 105 is close to both the logic unit 151 and the analog unit 153. The non-conductive portion 104 has a planar shape that extends over the entire region immediately below the first conductive ring 125.
In the semiconductor chip 100, the sealing ring region 106, in the vicinity of the surface of the silicon substrate 101, a first diffusion layer of the same conductivity type as the conductivity type of the silicon substrate 101 (p ⁺ diffusion layer 113) is provided, p ⁺ diffusion layer 113 A second diffusion layer (n-well 111) having a conductivity type opposite to that of the silicon substrate 101 is provided in contact with the lower surface of the silicon substrate 101. The seal ring 105 is provided in contact with the surface of the p ⁺ diffusion layer 113. The lower surface of p ⁺ diffusion layer 113 and the lower surface of n well 111 constitute non-conductive portion 104. Further, the outer periphery of the side surface of the p ⁺ diffusion layer 113 is covered and insulated by the element isolation film 121.
In this configuration, the seal ring 105 has a plurality of ring-shaped conductive films adjacent to each other through an interlayer insulating film, and the seal ring 105 is formed on the surface of the p ⁺ diffusion layer 113 in the formation region of the non-conductive portion 104. A plurality of connected columnar conductive plugs may be provided, and the conductive plugs may be arranged in a flat lattice pattern in a region where the non-conductive portion 104 is formed.

Hereinafter, the semiconductor chip 100 shown in FIGS. 1 to 3 will be described in more detail.
2 and 3, in the semiconductor chip 100, the first insulating film 123, the second insulating film 127, the third insulating film 131, the fourth insulating film 135, and the like are formed on the silicon substrate 101 (p substrate). A fifth insulating film 139, a sixth insulating film 143, and a passivation film 147 are stacked in this order.

  The logic unit 151 and the analog unit 153 have an n well 111 and a p well 109 adjacent to each other in the vicinity of the surface of the silicon substrate 101. The p-well 109 is terminated in the logic unit 151 or the analog unit 153.

On the surface of the silicon substrate 101 provided with the n-well 111, a gate oxide film 117 and a gate electrode 119 are laminated in this order. A p ⁺ diffusion layer 113 and an n ⁺ diffusion layer 115 functioning as a source / drain region are provided in a region above the n well 111 of the silicon substrate 101. A gate oxide film 117 and a gate electrode 119 are also stacked in this order on the p-well 109. An n ⁺ diffusion layer 115 functioning as a source / drain region and a p ⁺ diffusion layer 113 are provided in a region above the p well 109 of the silicon substrate 101. The p ⁺ diffusion layer 113 and the n ⁺ diffusion layer 115 are separated by the element isolation film 121.

The p ⁺ diffusion layer 113, the n ⁺ diffusion layer 115, and the gate electrode 119 are connected to the connection plug 124. The connection plug 124 is a conductive plug embedded in the first insulating film 123 and penetrating through the first insulating film 123. The upper surface of the connection plug 124 is connected to the first wiring 126 embedded in the second insulating film 127.

In the region where the seal ring 105 is provided (seal ring region 106), an n-well 111 is provided near the surface of the silicon substrate 101 (p-substrate), and a p ⁺ diffusion layer 113 is formed in contact with the surface of the p-well 109. Has been. The outer periphery of the side surface of each p ⁺ diffusion layer 113 is insulated by the element isolation film 121. The first conductive ring 125 provided in the first insulating film 123 is connected to the p ⁺ diffusion layer 113 at the bottom surface and connected to the bottom surface of the second conductive ring 129 at the top surface. From the first conductive ring 125 toward the upper layer, the second conductive ring 129, the third conductive ring 133, the fourth conductive ring 137, the fifth conductive ring 141, and the sixth conductive ring 145 are connected in this order. The n-well 111 in the seal ring region 106 and the p-well 109 in the analog portion 153 are separated by the silicon substrate 101 (p substrate).

  The second conductive ring 129, the third conductive ring 133, the fourth conductive ring 137, the fifth conductive ring 141, and the sixth conductive ring 145 are respectively a second insulating film 127, a third insulating film 131, and a fourth insulating film 135. It is made of a conductive material embedded in a groove-like recess formed in the fifth insulating film 139 and the sixth insulating film 143, and penetrates through the insulating film. These conductive rings are formed of a metal such as copper (Cu) and can be formed by a single damascene method, a dual damascene method, or the like.

  The connection plug 124 and the first conductive ring 125 are provided at the same level of the layer structure provided on the silicon substrate 101 (first layer), and these can be formed in the same process using the same material. is there. Similarly, the first wiring 126 and the second conductive ring 129 are provided at the same level in the above layer structure, and these can be formed from the same material in the same process.

Between the seal ring 105 constituted by the first conductive ring 125 to the sixth conductive ring 145 and the silicon substrate 101,
(I) a junction between the p ⁺ diffusion layer 113 and the n-well 111, and
(Ii) There are two pn junctions at the junction between the n-well 111 and the silicon substrate 101. In the vicinity of the junction interface of these pn junctions, a carrier depletion layer is formed and a capacitance is generated. In this reference example , such a capacitor is arranged in series in a path from the logic unit 151 to the analog unit 153 via the seal ring 105. For this reason, while a junction part functions as the non-conduction part 104, the sum total of the capacity | capacitance C in Formula (1) mentioned above can be made small, and the impedance Z in a path | route can be increased effectively.

Next, a method for manufacturing the semiconductor chip 100 shown in FIGS. 1 to 3 will be described.
The semiconductor chip 100 is manufactured as follows using, for example, an existing method. First, an element isolation film 121 (STI: shallow trench isolation) is formed on the silicon substrate 101. Next, for example, a SiO ₂ film is formed on the silicon substrate 101 as the gate oxide film 117, a polycrystalline silicon film is formed as the gate electrode 119 on the SiO ₂ film, and a gate is formed at a predetermined position on the silicon substrate 101. Form. Then, a p-well 109 and an n-well 111 are formed at predetermined positions near the surface of the silicon substrate 101. A p ⁺ diffusion layer 113 and an n ⁺ diffusion layer 115 are formed at predetermined positions near the surface of the silicon substrate 101 above the p well 109 and the n well 111.

  Subsequently, a first insulating film 123 is provided on the entire upper surface of the silicon substrate 101, and the upper part of the connection plug 124 and the first conductive ring 125 in the first insulating film 123 is formed as an opening by using a photolithography technique. A mask pattern to be formed is formed, and the formation regions of the connection plug 124 and the first conductive ring 125 are selectively removed. Then, a metal film of the material of the connection plug 124 and the first conductive ring 125 is provided on the entire upper surface of the silicon substrate 101. The metal film is, for example, a barrier metal film made of a laminated film in which a titanium (Ti) film and a titanium nitride (TiN) film are laminated in this order from the bottom, and tungsten formed so as to be in contact with the barrier metal film and bury a recess. (W) A film is used. Then, the metal film formed on the first insulating film 123 is removed by, for example, a CMP (Chemical Mechanical Polishing) method. Thereby, the connection plug 124 and the first conductive ring 125 are obtained.

  Next, a second insulating film 127 is provided on the entire upper surface of the first insulating film 123, and in the same manner, the formation regions of the first wiring 126 and the second conductive ring 129 of the second insulating film 127 are selectively removed. A recess is formed. A barrier metal film composed of a laminated film in which a tantalum (Ta) film and a tantalum nitride (TaN) film are laminated in this order from below on the entire upper surface of the second insulating film 127, and a recess in contact with the barrier metal film. Cu films provided so as to be embedded are sequentially formed. Further, the metal film formed on the second insulating film 127 is removed by, for example, a CMP method. Thereby, the first wiring 126 and the second conductive ring 129 are obtained.

Further, similarly, the third insulating film 131, the third conductive ring 133, the fourth insulating film 135, the fourth conductive ring 137, the fifth insulating film 139, the fifth conductive ring 141, and the sixth insulating film 143 are formed by the damascene method. , And the sixth conductive ring 145 are sequentially formed. Then, on the entire upper surface of the sixth conductive ring 145, as the passivation film 147, for example, a stacked film in which a SiN film, a SiO ₂ film, a SiO ₂ film, and a SiN film are stacked in this order from the bottom is formed. An annular groove that penetrates the passivation film 147 and surrounds the outer periphery of the seal ring 105 may be provided closer to the dicing surface 103 than the seal ring 105 of the passivation film 147. By so doing, it is possible to further reliably suppress the propagation of cracks toward the inside of the substrate during dicing when the semiconductor chip 100 is manufactured. As described above, the semiconductor chip 100 is obtained.

The first insulating film 123 to the sixth insulating film 143 are, for example, SiO ₂ films. Further, these interlayer insulating films may be low dielectric constant films. In this specification, the low dielectric constant film refers to a film having a relative dielectric constant k of 3.5 or less, for example. Examples of such a film include a SiOC film, a hydrogenated polysiloxane film, a methylpolysiloxane film, a hydrogenated methylpolysiloxane film, or a porous version of these films. An organic polymer may be used as the low dielectric constant film.

  Further, an insulating film functioning as an etching stopper film or a diffusion prevention film such as a SiN film can be provided between the insulating films of the first insulating film 123 to the sixth insulating film 143.

Next, the effect of the semiconductor chip 100 will be described.
In the semiconductor chip 100, the non-conducting portion 104 is provided in the seal ring region 106 where the seal ring 105 is formed. In the non-conductive portion 104, the first conductive ring 125 at the bottom layer of the seal ring 105 is connected to the n-type well 111 of the opposite conductivity type to the silicon substrate 101 through the p ⁺ diffusion layer 113. Between the first conductive ring 125 and the silicon substrate 101, a pn junction that functions as the non-conductive portion 104 is provided. Since the seal ring 105 and the silicon substrate 101 are separated by the capacitive junction at the non-conductive portion 104, the impedance expressed by the above-described equation (1) is increased due to the spread of the depletion layer at the junction, and noise propagation Can be suppressed. Further, the outer periphery of the side surface of the p ⁺ diffusion layer 113 connected to the first conductive ring 125 is separated from the silicon substrate 101 by the element isolation film 121 and insulated. For this reason, it is possible to sufficiently block the noise propagation path from the side surface of the p ⁺ diffusion layer 113 via the silicon substrate 101.

  Therefore, it is possible to suppress the noise generated in the logic unit 151 from propagating to the analog unit 153 through a path that passes through the silicon substrate 101, the seal ring 105, and the silicon substrate 101 in this order. Thereby, it is possible to suppress malfunction of an element provided in the analog unit 153.

In the present reference example , the junction that functions as the non-conductive portion 104 and inverts the conductivity type in each of the region close to the logic portion 151 and the region close to the analog portion 153 is the p ⁺ diffusion layer 113-n. There are two between the wells 111 and between the n well 111 and the silicon substrate 101 (p substrate). Therefore, as in a second reference example and embodiments (FIGS. 4 and 5) to be described later, propagation of low-frequency noise to the analog unit 153 is achieved as compared with a configuration in which the conductive type inversion portion is one place. Further, the configuration can be surely suppressed.

Further, in the present reference example and the second reference example and embodiment described later, since the non-conducting portion 104 is provided in each of the region close to the logic unit 151 and the region close to the analog unit 153, Compared to the configuration in which the non-conducting portion 104 is provided only in the region close to the analog portion 153 as in the third to fifth reference examples described later, the path from the logic portion 151 to the analog portion 153 is more Many non-conductive portions 104 can be arranged in series.

Furthermore, in this reference example , the non-conductive portion 104 formed below the diffusion layer of the conductivity type opposite to the surface of the silicon substrate 101 is an n-well 111-silicon substrate 101 (p substrate) bonding surface. Therefore, as in the configuration described below in implementation embodiment, as compared with a configuration in which the non-conducting portion 104 is in the n ⁺ diffusion layer 115- silicon substrate 101 bonding surface, and configured junction capacitance in the non-conducting portion 104 is small It has become.

  As described above, in the semiconductor chip 100, many non-conductive portions 104 are arranged in series in the conductive path from the logic unit 151 to the analog unit 153 via the seal ring 105. Further, the capacitance in the pn junction constituting one non-conducting portion 104 can be suitably reduced, and C in the above formula (1) can be suitably reduced. For this reason, the impedance Z can be suitably increased by effectively reducing the total of the capacitance C in the path. This effect is prominently exhibited when ω is small in the above formula (1), and the semiconductor chip 100 can further effectively suppress the propagation of low-frequency noise.

Further, in the semiconductor chip 100, the p ⁺ diffusion layer 113 constituting the non-conducting portion 104 can be formed in the same process as the p ⁺ diffusion layer 113 provided in the logic portion 151 and the analog portion 153. Further, the n-well 111 constituting the non-conducting portion 104 can be formed in the same process as the n-well 111 provided in the logic portion 151 and the analog portion 153. For this reason, it is not necessary to provide a new manufacturing process in order to form the non-conduction part 104, and it is a structure with easy manufacture.

Further, in the semiconductor chip 100, since the non-conducting portion 104 is provided over the entire region where the seal ring 105 is formed, the device configuration can be further simplified as compared with third to fifth reference examples described later. It becomes possible. For this reason, it becomes the structure which can be manufactured still more easily.

Further, the seal ring 105 is in contact with the surface of the silicon substrate 101 over the entire circumference of the seal ring 105. For this reason, the function as a seal ring is suitably ensured in the perimeter of the dicing surface 103 of the semiconductor chip 100 compared with the 6th reference example mentioned later. A passivation film 147 covers the entire upper surface of the seal ring 105. As a result, it is possible to prevent cracks generated during dicing from reaching the logic unit 151 or the analog unit 153 provided inside the seal ring 105. In addition, the semiconductor chip 100 is configured to be inhibited from being affected by moisture and ions from the ambient atmosphere.

Further, since the seal ring 105 is in contact with the surface of the silicon substrate 101, as will be described later in the sixth reference example , even when plasma is used at the time of manufacturing the seal ring 105, the charge is transferred to the silicon substrate. It can escape to the side of 101. Therefore, charge accumulation in the seal ring 105 due to such a manufacturing process is suppressed. Therefore, while ensuring the function as the seal ring 105 sufficiently, the noise propagation between the logic unit 151 and the analog unit 153 is suppressed, and the manufacturing stability is excellent.

  As described above, the semiconductor chip 100 has a configuration in which the distribution of digital noise in the chip by the seal ring 105 is reduced, and thus can be suitably used for, for example, a semiconductor device integrated circuit in which a digital area and an analog area are mixedly mounted. .

  2 and 3, the configuration in which the n-well 111 in the seal ring region 106 and the p-well 109 in the logic unit 151 or the analog unit 153 are separated from each other is described as an example. Good. As shown in FIGS. 2 and 3, the n well 111 and the p well 109 are separated from each other by the silicon substrate 101 (p substrate), whereby the pn junction on the side surface of the n well 111 becomes the n well 111. -Since the silicon substrate 101 (p substrate) is formed, the junction capacitance can be reduced as compared with the case where the n well 111 and the p well 109 are in contact with each other to form a pn junction. For this reason, the impedance between the logic unit 151 and the analog unit 153 can be increased more effectively, and the noise propagation via the side surface of the n-well 111 can be more effectively suppressed.

Further, in FIG. 2 and FIG. 3, p ⁺ diffusion layer 113 has been illustrated a structure in which are provided separately for each of the first conductive ring 125, a p ⁺ diffusion layer 113 each of the first conductive A configuration in which the ring 125 is provided in common may be employed. By separately providing the p ⁺ diffusion layer 113 corresponding to each of the first conductive rings 125, the effect of increasing the impedance can be exhibited more remarkably.

2 and FIG. 3, the configuration in which one n-well 111 is formed over the entire bottom of the seal ring 105 made of a plurality of annular (three in this reference example ) conductive members has been described as an example. The well 111 may be divided and formed in the lower part of the p ⁺ diffusion layer 113 on the upper part. By so doing, it is possible to more effectively suppress noise propagation between the logic unit 151 and the analog unit 153.

2 and 3, the first insulating film 123 is formed with an annular recess, and the first conductive ring 125 is embedded in the recess. However, this reference example and the present specification are also described. In other reference examples and embodiments, the first insulating film 123 has a configuration in which a plurality of cylindrical recesses are provided at predetermined intervals in the circumferential direction, similar to the recesses for forming the connection plugs 124. A configuration may be employed in which a plurality of columnar conductive plugs embedded in the recess and connected to the second conductive ring 129 and having the same cross-sectional shape as the first conductive ring 125 (FIGS. 2 and 3) are provided. By adopting a structure having a columnar conductive plug instead of the first conductive ring 125, the resistance of the seal ring 105 in the layer of the first insulating film 123 can be increased, so that low frequency noise to the analog portion 153 is reduced. Propagation can be suppressed even more reliably.

  In the case where a columnar conductive plug is provided in the first insulating film 123 instead of the first conductive ring 125, the plurality of conductive plugs can be arranged in a plane pattern in an oblique lattice shape such as a staggered lattice shape. In this way, the function as the seal ring 105 can be more effectively exhibited also in the layer of the first insulating film 123.

In the following reference examples and embodiments, differences from the first reference example will be mainly described.

(Second reference example )
In the semiconductor chip described in the first reference example , the cross-sectional configuration of the seal ring region 106 may be as follows. Also in this reference example , the planar configuration of the semiconductor chip is the configuration described above with reference to FIG. FIG. 4 is a cross-sectional view showing the configuration of the semiconductor device of this reference example . 4 shows the II-II ′ cross section of FIG. 1 corresponding to FIG. 3 in the first reference example , but the analog section 153 in FIG. The configuration can be applied.

As shown in FIG. 4, in the semiconductor device of this reference example , a diffusion layer (n ⁺ diffusion layer 115 and n well 111) having a conductivity type opposite to the conductivity type of the silicon substrate 101 is provided in the vicinity of the surface of the silicon substrate 101. And a seal ring 105 is connected to the surface of the n ⁺ diffusion layer 115. The junction surface of the n-well 111 constitutes a non-conducting portion 104.
In this configuration, the seal ring 105 includes a plurality of first conductive rings 125 to sixth conductive rings 145 that are adjacent to each other through the first insulating film 123 to the sixth insulating film 143. The seal ring 105 may have a plurality of columnar conductive plugs connected to the surface of the n-well 111, and the conductive plugs may be arranged in a plane in a diagonal lattice pattern in the formation region of the non-conductive portion 104.

More specifically, the cross-sectional structures of the logic unit 151 and the analog unit 153 have the same configuration as that of the first reference example , for example. Further, as shown in FIG. 4, the basic structure of the sealing ring region 106 is the same as that in FIG. 2 and FIG. 3, n ⁺ diffusion layer changes to a p ⁺ diffusion layer 113 on top of the n-well 111 in the silicon substrate 101 115, provided that the bottom surface of the first conductive ring 125 is connected to the surface of the silicon substrate 101 on which the n ⁺ diffusion layer 115 is provided. The outer periphery of the side surface of each n ⁺ diffusion layer 115 is covered with the element isolation film 121 and separated from each other.

4 and FIG. 5 to be described later in the embodiment and the fifth reference example exemplify a configuration in which the n ⁺ diffusion layer 115 is provided separately for each first conductive ring 125. The n ⁺ diffusion layer 115 may be provided in common for each first conductive ring 125. By separately providing the n ⁺ diffusion layer 115 corresponding to each of the first conductive rings 125, the effect of increasing the impedance can be exhibited more remarkably.

4 illustrates a configuration in which one n-well 111 extends over the entire lower portion of a plurality (three in FIG. 4) of n ⁺ diffusion layers 115. As described above in the first reference example , FIG. The n-well 111 may be divided into the lower portions of the upper n ⁺ diffusion layer 115. By so doing, it is possible to more effectively suppress noise propagation between the logic unit 151 and the analog unit 153.

Also in this reference example , the bottom surface of the seal ring 105, that is, the bottom surface of the first conductive ring 125 is formed on the surface of the silicon substrate 101 provided with the n ⁺ diffusion layer 115 of the opposite conductivity type to the silicon substrate 101 (p substrate). It touches. As the non-conducting portion 104, a junction portion between the n well 111 provided below the n ⁺ diffusion layer 115 and the silicon substrate 101 (p substrate) is provided. In the path from the logic unit 151 to the analog unit 153 via the seal ring 105, two non-conducting units 104 constituted by pn junctions are arranged in series, and the seal ring 105 and the silicon substrate 101 are connected to each other. Since the non-conducting portion 104 is separated by the capacitive junction, the impedance becomes high, and noise propagation can be suppressed as in the first reference example .

Furthermore, when comparing the configuration of the implementation forms you later the structure of the present embodiment, in the implementation mode (Fig. 5), immediately below the first conductive ring 125, near the surface of the silicon substrate 101 (p substrate) In contrast to the n ⁺ diffusion layer 115, the reference example (FIG. 4) has an n well 111 in addition to the n ⁺ diffusion layer 115. The capacity between the n well 111 and the silicon substrate 101 is smaller than the capacity between the n ⁺ diffusion layer 115 and the silicon substrate 101. Therefore, according to the configuration shown in FIG. 4, as compared to the implementation form, to reduce the junction capacitance. For this reason, it is the structure excellent in the increase effect of the impedance by providing the non-conduction part 104 further. Therefore, it is the structure which can suppress propagation of noise still more reliably.

  Also in FIG. 4, similarly to FIGS. 2 and 3, the n-well 111 in the seal ring region 106 and the p-well 109 in the logic portion 151 or the analog portion 153 are separated from each other. Compared with the case where a pn junction is formed in contact with the well 109, the junction capacitance can be reduced. For this reason, the impedance between the logic unit 151 and the analog unit 153 can be increased more effectively.

(Implementation form)
In the semiconductor chip described in the first reference example , the cross-sectional configuration of the seal ring region 106 may be as follows. Also in this embodiment, the planar configuration of the semiconductor chip is the same as that described above with reference to FIG. FIG. 5 is a cross-sectional view showing the configuration of the semiconductor device of this embodiment. FIG. 5 shows the II-II ′ section of FIG. 1 corresponding to FIG. 3 in the first reference example , but the analog section 153 in FIG. The configuration can be applied.

As shown in FIG. 5, the basic configuration of the semiconductor device seal ring region 106 of this embodiment is the same as that of the semiconductor chip described in the second reference example , but the n-well 111 is not provided in the silicon substrate 101. The point is different.

Also in this embodiment, the bottom surface of the seal ring 105, that is, the bottom surface of the first conductive ring 125 is formed on the surface of the silicon substrate 101 provided with the n ⁺ diffusion layer 115 having the conductivity type opposite to that of the silicon substrate 101 (p substrate). It touches. As the non-conducting portion 104, a junction between the n ⁺ diffusion layer 115 and the silicon substrate 101 (p substrate) is provided. For this reason, also in the present embodiment, as in the second reference example , the non-conducting portion 104 constituted by the pn junction portion is included in the path from the logic portion 151 to the analog portion 153 via the seal ring 105. Two are arranged in series, and the seal ring 105 and the silicon substrate 101 are separated by capacitive bonding at the non-conducting portion 104, so that the impedance becomes high and noise propagation can be suppressed.

In FIG. 5, n ⁺ diffusion layers 115 are separately provided corresponding to the plurality of first conductive rings 125. For this reason, the effect of increasing the impedance can be exhibited more significantly as compared with the configuration in which one n ⁺ diffusion layer 115 is provided below the plurality of first conductive rings 125.

Also in this embodiment, the p well 109 is not formed so as to extend over the seal ring region 106 but is terminated at the logic unit 151 or the analog unit 153. The pn junction surface that functions as the non-conducting portion 104 is the junction surface between the n ⁺ diffusion layer 115 and the silicon substrate 101 (p substrate). When the p well 109 is provided over the seal ring region 106, the pn junction surface becomes the junction surface between the n ⁺ diffusion layer 115 and the p well 109. However, in this embodiment, the n ⁺ diffusion layer 115 is not provided without providing the p well 109. By providing a bonding surface between the silicon substrate 101 and the silicon substrate 101 (p substrate), the bonding capacity can be further reduced. For this reason, it is possible to more effectively suppress the noise propagation by increasing the impedance more effectively.

( Third reference example )
In the first to second reference examples and the embodiment, the non-conductive portion 104 is formed in the entire seal ring region 106, but the non-conductive portion 104 shown in FIGS. 3 to 5 is at least the logic portion 151 or the analog portion. A configuration may be employed in which the portion 153 is provided in the vicinity. In this reference example and the following reference examples , a case where the non-conducting portion 104 is provided close to the analog portion 153 will be described as an example. Moreover, in this reference example , the case where the structure of the non-conduction part 104 is a structure of a 1st reference example is demonstrated to an example. Configuration of the non-conducting portion 104 for a semiconductor chip is the configuration of the second reference example Oyo BiMinoru facilities embodiment, respectively, will be described later in the fourth and fifth reference example.

FIG. 6 is a plan view showing the configuration of the semiconductor chip of this reference example . The basic configuration of the semiconductor chip shown in FIG. 6 is the same as that of the semiconductor chip 100 (FIG. 1) in the first reference example , but the seal ring region 106 is a first region having a cross-sectional structure shown in FIG. 106a and the second region 106b having the cross-sectional structure shown in FIG. The first region 106 a is a region that does not have the non-conductive portion 104, and the second region 106 b is a region that has the non-conductive portion 104.

7 is a cross-sectional view taken along the line II ′ of FIG. In FIG. 7, it is a figure which shows the cross-sectional structure of the 1st area | region 106a. In FIG. 7, a p-well 109 is provided in the vicinity of the upper surface of the silicon substrate 101 from the logic unit 151 to the seal ring region 106. A p ⁺ diffusion layer 113 is formed in contact with the surface of the p well 109. The outer periphery of the side surface of the p ⁺ diffusion layer 113 is separated from each other by the element isolation film 121. The bottom surface of the first conductive ring 125 is in contact with the surface of the silicon substrate 101 provided with the p ⁺ diffusion layer 113.

In the semiconductor chip shown in FIG. 7, the configuration described above with reference to FIG. 3 in the first reference example is applied to the II-II ′ section. The seal ring region 106 in FIG. 3 corresponds to the second region 106b in this reference example .

  Returning to FIG. 6, the second region 106 b can be provided, for example, in a region adjacent to the analog unit 153. In addition to a region adjacent to the analog unit 153, it is preferable to provide a predetermined distance, for example, a region where a margin of a minimum distance in the substrate surface between the logic unit 151 and the analog unit 153 is added.

  More specifically, when L is the minimum distance between the end portions of the logic unit 151 and the analog unit 153 in the substrate surface, the length is about L from the region adjacent to the analog unit 153 and the end of the analog unit 153. The second area 106b is set up to the distant position. By so doing, it is possible to more reliably suppress noise generated in the logic unit 151 from propagating to the logic unit 151 via the seal ring 105.

In the configuration of this reference example , the seal ring region 106 is the second region 106 b having the non-conductive portion 104 in the region adjacent to the analog unit 153 and in the vicinity thereof. For this reason, the effect which suppresses the propagation of the noise which passes along the seal ring 105 is acquired similarly to the 1st reference example .

In this reference example , in the second region 106b, the bonding surface that functions as the non-conductive portion 104 between the first conductive ring 125 and the silicon substrate 101 and whose conductivity type is reversed is the p ⁺ diffusion layer 113. There are two between the n-well 111 and between the n-well 111 and the silicon substrate 101 (p-substrate). Thus, by way of the seal ring 105 from the logic unit 151 in the path leading to the analog unit 153, the non-conducting portion 104 constituted by the pn junction are arranged in two series, the fourth will be described later, second As in the fifth reference example , compared to a configuration in which there is one conductivity-type inversion portion provided in the path, it is a configuration that can more reliably suppress the propagation of low-frequency noise to the analog unit 153. Yes.

( Fourth reference example )
In the third reference example , the configuration described in the second reference example (FIG. 4) may be applied to the region adjacent to the analog unit 153 and the second region 106b provided in the vicinity thereof.

Also in this configuration, the non-conductive portion 104 is provided in the seal ring region 106 in a region adjacent to the analog portion 153 and in the vicinity thereof. For this reason, one non-conducting part 104 composed of a pn junction is arranged in the path from the logic part 151 to the analog part 153 via the seal ring 105, and as in the third reference example. The effect of suppressing the propagation of noise via the seal ring 105 is obtained.

Furthermore, when comparing the configuration of the present embodiment and the configuration of the fifth reference example will be described later, in the fifth reference example, immediately below the first conductive ring 125, in the vicinity of the surface of the silicon substrate 101, n ⁺ diffusion In contrast to the layer 115, the reference example includes an n well 111 in addition to the n ⁺ diffusion layer 115. Therefore, in this reference example , the junction capacitance can be reduced as compared with the fifth reference example . For this reason, it is the structure excellent in the increase effect of the impedance by providing the non-conduction part 104 further. Therefore, it is the structure which can suppress propagation of noise still more reliably.

( Fifth reference example )
In a third reference example, the configuration of the second region 106b provided in the region and the vicinity thereof adjacent to the analog unit 153, may be applied to the above-described configuration in implementation form (Figure 5).

Also in this configuration, the non-conductive portion 104 is provided in the seal ring region 106 in a region adjacent to the analog portion 153 and in the vicinity thereof. For this reason, one non-conducting portion 104 composed of a pn junction is arranged in the path from the logic portion 151 to the analog portion 153 via the seal ring 105, and the third and fourth reference examples. Similarly to the above, the effect of suppressing the propagation of noise via the seal ring 105 can be obtained.

( Sixth reference example )
In the above reference examples and embodiments, the logic unit 151 and the analog unit 153 are connected by increasing the impedance by providing a pn junction that functions as the non-conduction unit 104 in the conduction path between the logic unit 151 and the analog unit 153. Although the non-conductive state is set, the non-conductive part 104 may be configured to block the conductive path from the logic part 151 to the analog part 153 via the seal ring 105, and a part of the seal ring 105 is lost. A configuration in which an insulating film is embedded in the defect portion may be employed.

The semiconductor chip of the present reference example, as in the third to fifth reference example has a planar shape shown in FIG. 6 is the same as that described above with reference to FIG. And the structure of II-II 'cross section is taken as the structure shown in FIG. FIG. 8 is a cross-sectional view showing the configuration of the semiconductor chip of this reference example .

As shown in FIG. 8, the second region 106b having the non-conducting portion 104 is provided close to the logic portion 151 or the analog portion 153 (analog portion 153 in this reference example ).
Further, in the seal ring region 106, in the second region 106b provided with the non-conductive portion 104, the silicon substrate 101 and the seal ring 105 are separated by the first insulating film 123, and the first insulating film 123 is non-conductive. The seal ring 105 is connected to the silicon substrate 101 in a region (first region 106a) other than the second region 106b in which the non-conductive portion 104 is provided. .

  More specifically, the basic configuration of the second region 106b is the same as that of the first region 106a shown in FIG. 7, except that the p-well 109 terminates in the analog portion 153, and reaches the second region 106b. The difference is that the first conductive ring 125 is not provided. In the second region 106 b, the lowermost layer of the seal ring 105 is a second conductive ring 129 provided in contact with the first insulating film 123, and the nonconductive portion 104 is between the seal ring 105 and the silicon substrate 101. The first insulating film 123 functioning as is interposed. The seal ring 105 and the silicon substrate 101 are insulated by the first insulating film 123.

Also in this reference example , as described in the third reference example , the second region 106b can be provided in a region adjacent to the analog unit 153, for example. In addition to a region adjacent to the analog unit 153, it is preferable to provide a predetermined distance, for example, a region where a margin of a minimum distance in the substrate surface between the logic unit 151 and the analog unit 153 is added.

Next, effects of the semiconductor chip (FIGS. 6 to 8) of this reference example will be described.
In the semiconductor chip of this reference example , the first conductive ring 125 is partially missing in the layer of the first insulating film 123. Specifically, as shown in FIG. 8, in the region adjacent to the analog portion 153 and in the vicinity thereof, the seal ring region 106 which is the formation region of the seal ring 105 is the second region 106 b having the non-conductive portion 104. It is comprised by. In the second region 106b, since the bottom surface of the seal ring 105 is in contact with the first insulating film 123, the seal ring 105 and the silicon substrate 101 are not connected by the first conductive ring 125, and these are the first insulating film. It is insulated by 123 and is in a non-conductive state. For this reason, since the non-conduction part 104 can be made into the area | region where R is large in Formula (1) mentioned above, the impedance Z can be increased. Therefore, it is possible to suppress the noise generated in the logic unit 151 from propagating to the analog unit 153 through a path that passes through the silicon substrate 101, the seal ring 105, and the silicon substrate 101 in this order, for example. Thereby, it is possible to suppress malfunction of an element provided in the analog unit 153.

Further, the seal ring 105 does not contact the silicon substrate 101 only in the second region 106b, and the first conductive ring 125 contacts the surface of the p ⁺ diffusion layer 113 of the silicon substrate 101 in the first region 106a. Yes. Further, the conductive ring missing in the second region 106b is only the first conductive ring 125, and the other conductive rings are formed in an annular shape over the entire circumference. For this reason, the function as a seal ring is suitably ensured around the entire circumference of the dicing surface 103 of the semiconductor chip 100.

  Although technical fields are different, Patent Document 2 describes a semiconductor integrated circuit device having a ring-shaped conductor fence constituting a moisture-resistant ring. This semiconductor integrated circuit device has an insulating film embedded in a silicon substrate. And the conductor fence is connected to this insulating film through conductor areas, such as a polycrystalline silicon, in the perimeter.

  However, as a result of studies by the present inventors, it has been found that in the above-described configuration, there is a concern that in the manufacturing process, components such as rupture of the Cu film constituting the conductor fence and destruction of the insulating film may occur. As a cause of this, in the case where the conductor fence is connected to the insulating film over the entire circumference, there is no escape route for electric charges from the conductor fence. Therefore, when the plasma is irradiated in the manufacturing process, the conductor fence It was presumed that charges are easily accumulated therein, and that the accumulation of the charges tends to cause deterioration of the constituent members.

On the other hand, in the semiconductor chip of this reference example (FIGS. 6 to 8), the seal ring region 106 is the first region 106a in the region adjacent to the analog unit 153 and the region other than the vicinity thereof. In the first region 106a, the first conductive ring 125 is connected to a region of the same conductivity type as that of the silicon substrate 101, specifically, the surface of the silicon substrate 101 provided with the p ⁺ diffusion layer 113. ing. For this reason, even when plasma is used in the process of forming the seal ring 105, it is possible to suppress the charge from being accumulated in the seal ring 105 and to effectively release the charge to the silicon substrate 101 side. Therefore, the noise propagation from the logic unit 151 to the analog unit 153 is suppressed, and the manufacturing stability is further improved. Therefore, the semiconductor chip 100 has a configuration that can reliably suppress the deterioration of the constituent members due to the manufacturing process.

( Seventh reference example )
In the reference example and the embodiment described above, an endless ring in which the seal ring 105 is closed is formed in a region adjacent to the analog unit 153 and in the vicinity thereof, so that the conduction between the seal ring 105 and the silicon substrate 101 is cut off. Although the semiconductor chip having the structure in which the region functioning as the portion 104 extends in the in-plane direction of the substrate has been described, the seal ring 105 may be a ring lacking a part of the circumference. A structure having an interlayer insulating film for cutting the seal ring 105 in the normal direction of the substrate 101 may also be employed.

  Specifically, in the second region 106b, the seal ring 105 has a plurality of columnar conductors embedded in the first insulating film 123 to the sixth insulating film 143 and spaced apart from each other, In this configuration, the conductor has a planar arrangement in an oblique lattice shape. The first insulating film 123 to the sixth insulating film 143 separating the plurality of columnar conductors are regions where R in Formula (1) is large, and function as the non-conductive portion 104.

Further, by combining the configuration of the present embodiment with the configurations of the first to sixth reference examples and the embodiments described above, it is possible to more reliably suppress noise propagation.

  FIG. 9 is a plan view showing the configuration of such a semiconductor chip. In the semiconductor chip shown in FIG. 9, the seal ring 105 is cut from the upper surface to the lower surface in the second region 106b. In the second region 106b, striped annular conductors having the cross-sectional shapes shown in FIGS. 3 to 6 are arranged in an oblique lattice shape, specifically, a staggered lattice shape.

As mentioned above, although the reference example and embodiment of this invention were described with reference to drawings, these are illustrations of this invention and can also employ | adopt various structures other than the above.

For example, in the above reference examples and embodiments, the case where the seal ring 105 has a configuration of triple annular conductors has been described as an example, but the number of annular conductors in the seal ring 105 is not particularly limited. And can be designed as appropriate. When the seal ring 105 includes a plurality of rings, particularly triple or more rings, the original function as the seal ring 105 can be more effectively exhibited even when the non-conductive portion 104 is provided. it can.

Further, in the above reference examples and embodiments, the configuration in which the seal ring 105 is provided along the dicing surface 103 inside the dicing surface 103 has been described as an example, but will be described later with reference to FIG. In addition, the seal ring 105 is not necessarily provided along the dicing surface 103.

In the above reference examples and embodiments, the case where the seal ring 105 is configured to surround the outside of the logic unit 151 and the analog unit 153 has been described as an example. However, at least one of the logic unit 151 and the analog unit 153 is surrounded. The configurations of the above reference examples and embodiments can also be applied to a semiconductor chip having a guard ring.

Specifically, as shown in FIG. 10, an annular guard ring that surrounds the outer periphery of the logic unit 151 is provided, and an analog unit 153 is provided outside the guard ring. You may apply the structure as described in a reference example and embodiment to the formation area of a guard ring. Also in this case, by providing at least the non-conducting portion 104 in a region adjacent to the analog portion 153 and in the vicinity thereof, it is possible to suppress noise from propagating from the logic portion 151 to the analog portion 153 via the seal ring 105.

  In the above description, the configuration in which the complementary field effect transistors are provided in the logic unit 151 and the analog unit 153 has been described as an example. However, the configuration of the logic unit 151 and the analog unit 153 is not limited to this configuration. Further, in the above description, the logic unit 151 and the analog unit 153 are formed as element regions on the silicon substrate 101 and have a guard ring surrounding at least the outer periphery of the logic unit 151. However, the element region is the logic unit 151. In addition, the analog unit 153 is not limited, and has at least one element region that may cause noise propagation, and at least one of the region and the other element region is provided inside the guard ring. It can be configured.

DESCRIPTION OF SYMBOLS 100 Semiconductor chip 101 Silicon substrate 103 Dicing surface 104 Non-conducting part 105 Seal ring 106 Seal ring area 106a First area 106b Second area 109 p well 111 n well 113 p ⁺ diffusion layer 115 n ⁺ diffusion layer 117 gate oxide film 119 Gate electrode 121 Element isolation film 123 First insulating film 124 Connection plug 125 First conductive ring 126 First wiring 127 Second insulating film 129 Second conductive ring 131 Third insulating film 133 Third conductive ring 135 Fourth insulating film 137 Fourth conductive ring 139 Fifth insulating film 141 Fifth conductive ring 143 Sixth conductive film 145 Sixth conductive ring 147 Passivation film 151 Logic part 153 Analog part

Claims (2)

A semiconductor device having first and second element regions,
A semiconductor substrate;
An interlayer insulating film provided on the semiconductor substrate;
An annular guard ring that is formed of a conductive film embedded in the interlayer insulating film and surrounds the outer periphery of the first element region;
A first diffusion layer that is provided in the vicinity of the surface of the semiconductor substrate and overlaps the guard ring in plan view, and has a conductivity type opposite to the conductivity type of the semiconductor substrate;
A well of the same conductivity type as that of the semiconductor substrate provided in the vicinity of the surface of the semiconductor substrate in each of the first and second element regions;
A non-conductive portion that blocks conduction of a path from the first element region to the second element region via the guard ring;
Have
The bottom surface of the guard ring are in contact with the surface of the first semiconductor substrate which diffusion layer is provided in,
The bonding surface between the first diffusion layer and the semiconductor substrate constitutes the non-conducting portion, and the non-conducting portion is provided in each of the regions adjacent to the first element region and the second element region. Is provided,
A portion of the semiconductor substrate is interposed between the well and the non-conductive portion, and the well and the non-conductive portion are separated by the portion of the semiconductor substrate,
The well terminates in the first or second device region;
The semiconductor device, wherein the guard ring is not electrically connected to a fixed potential. The semiconductor device according to claim 1,
The semiconductor device, wherein the non-conducting portion is provided in a region where the guard ring is formed.

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