The present disclosure relates to a solid-state imaging element, a manufacturing method, and an electronic apparatus, and more particularly, to a solid-state imaging element, a manufacturing method, and an electronic apparatus capable of manufacturing more conforming products.
Conventionally, a solid-state imaging element having a layered structure in which a plurality of semiconductor substrates is layered, is provided with a pad formed of aluminum or the like for electrical connection with the outside.
For example, Patent Document 1 discloses a solid-state imaging element having a three-layer structure, and shows a structure in which pads are arranged in the first and the third layers, or a structure in which pads are arranged in the second and the third layers.
Meanwhile, conventionally, a manufacturing method has been adopted in which an inspection for guaranteeing a known good die (KGD) is performed for each semiconductor substrate before being layered, and only conforming products are bonded. However, for example, inspection pads are not provided for some semiconductor substrates. Therefore, it is not possible to perform the inspection for KGD on such semiconductor substrates, and it has been required to manufacture more conforming products.
The present disclosure has been made in view of such a situation, and an object of the present disclosure is to make it possible to manufacture more conforming products.
A solid-state imaging element according to an aspect of the present disclosure includes: a first semiconductor substrate provided with a first pad used for connection with the outside, separately from a dedicated pad used for inspection in a manufacturing process; and a second semiconductor substrate provided with a second pad used for inspection in a manufacturing process, in which the first pad and the second pad are electrically connected to each other via a first electrode provided in the first semiconductor substrate and a second electrode provided in the second semiconductor substrate.
A manufacturing method according to an aspect of the present disclosure is a manufacturing method of a solid-state imaging element including a first semiconductor substrate provided with a first pad used for connection with the outside, separately from a dedicated pad used for inspection in a manufacturing process, and a second semiconductor substrate provided with a second pad used for inspection in a manufacturing process, the method including electrically connecting the first pad and the second pad to each other via a first electrode provided in the first semiconductor substrate and a second electrode provided in the second semiconductor substrate.
An electronic apparatus according to an aspect of the present disclosure includes a solid-state imaging element including: a first semiconductor substrate provided with a first pad used for connection with the outside, separately from a dedicated pad used for inspection in a manufacturing process; and a second semiconductor substrate provided with a second pad used for inspection in a manufacturing process, in which the first pad and the second pad are electrically connected to each other via a first electrode provided in the first semiconductor substrate and a second electrode provided in the second semiconductor substrate.
According to an aspect of the present disclosure, a first semiconductor substrate is provided with a first pad used for connection with the outside, separately from a dedicated pad used for inspection in a manufacturing process, and a second semiconductor substrate is provided with a second pad used for inspection in a manufacturing process. Then, the first pad and the second pad are electrically connected to each other via a first electrode provided in the first semiconductor substrate and a second electrode provided in the second semiconductor substrate.
Hereinafter, specific embodiments to which the present technology is applied will be described in detail with reference to the drawings.
<First Configuration Example of Solid-State Imaging Element>
A solid-state imaging element 11 illustrated in
In the sensor chip 12, for example, a plurality of pixels (not illustrated) for the solid-state imaging element 11 to perform imaging is provided, and an aluminum pad 21 and contact electrodes 22 are provided.
The aluminum pad 21 is used for wire bonding to electrically connect the solid-state imaging element 11 to the outside, and an opening 23 is formed in the sensor chip 12 so that the aluminum pad 21 is exposed. Furthermore, when the sensor chip 12 is dug to form the opening 23, a recess 24 corresponding to the shape of the opening 23 is formed in the aluminum pad 21. Note that the recess 24 has such a depth that the barrier metal of the aluminum pad 21 is scraped, for example.
The contact electrodes 22 are electrodes for electrically connecting the aluminum pad 21 to the logic chip 13, and are provided at a plurality of respective locations (12 locations in the example illustrated in
In the logic chip 13, for example, a logic circuit (not illustrated) for executing signal processing necessary for the solid-state imaging element 11 to perform imaging is provided, and an aluminum pad 31, contact electrodes 32, dummy patterns 33, and an I/O circuit 34 are provided.
The aluminum pad 31 is used for inspection for guaranteeing KGD for the logic chip 13. For example, in the inspection, an opening is provided for electrical connection to the aluminum pad 31, and a backfill portion 35 is provided by backfilling the opening after the inspection. Furthermore, when the logic chip 13 is dug to form the opening (not illustrated), a recess 36 corresponding to the shape of the opening is formed in the aluminum pad 31.
The aluminum pad 31 is also used for electrical connection with the sensor chip 12. For example, an opening region is formed in the aluminum pad 31 so as to correspond to the opening 23 formed in the sensor chip 12 in plan view, and the contact electrodes 32 are connected to a plurality of respective locations (12 locations in the example illustrated in
The contact electrodes 32 are electrodes for electrically connecting the aluminum pad 31 to the sensor chip 12, and are provided at a plurality of respective locations corresponding to the contact electrodes 22 of the sensor chip 12. For example, the contact electrodes 32 are formed of the same material as that of the contact electrodes 22, and the contact electrodes 32 are electrically and mechanically connected to the respective contact electrodes 22 using bonding (Cu—Cu direct bonding) of the same material on each exposed surface.
The dummy patterns 33 are formed of the same aluminum material as that of the aluminum pad 31 so as to partially fill the opening region (that is, a region corresponding to the opening 23 of the sensor chip 12) formed in the aluminum pad 31. For example, the dummy patterns 33 are not electrically connected and do not have a function as wiring.
The I/O circuit 34 is a semiconductor circuit including a transistor, wiring, and the like configured to control input and output of a signal to and from the solid-state imaging element 11. For example, the I/O circuit 34 is arranged at a position other than the region corresponding to the opening 23 of the sensor chip 12, and is arranged so as to overlap the region where the recess 36 is formed in the aluminum pad 31 in plan view in the example illustrated in
Note that the solid-state imaging element 11 has a structure in which the aluminum pad 21 of the sensor chip 12 and the aluminum pad 31 of the logic chip 13 are connected by Cu—Cu direct bonding between the contact electrodes 22 and the contact electrodes 32, but otherwise, bump bonding via solder may be used.
As illustrated in
Furthermore, a pixel region 41 in which a plurality of pixels is arranged in an array is provided at the center of the sensor chip 12, and a plurality of KGD-dedicated pads 42 is provided in the vicinity of the pixel region 41. Note that an opening of each KGD-dedicated pad 42 is backfilled after an inspection for guaranteeing KGD for the sensor chip 12 is performed.
The solid-state imaging element 11 is configured as described above, and the sensor chip 12 is inspected for KGD using the KGD-dedicated pads 42, and the logic chip 13 is inspected for KGD using the aluminum pads 31. Then, the sensor chip 12 and the logic chip 13 given the inspection results representing conforming products are selected, and bonding using the contact electrodes 22 and the contact electrodes 32 is performed in units of chips. As described above, by inspecting both the sensor chip 12 and the logic chip 13 for KGD, more conforming products of the solid-state imaging element 11 can be manufactured as compared with the conventional manufacturing method.
With the configuration of the solid-state imaging element 11 in which the aluminum pads 21 for connection to the outside are provided in the sensor chip 12, the depth of the openings 23 can be made shallower as compared with the configuration in which an aluminum pad for connection to the outside is provided in the second layer or the third layer, for example. As a result, the solid-state imaging element 11 can have a structure that allows easy wire bonding on the aluminum pads 21.
In the solid-state imaging element 11, each of the openings 23 that opens the corresponding aluminum pad 21 of the sensor chip 12 and the corresponding backfill portion 35 (that is, the opening for inspecting the logic chip 13 for the KGD) of the logic chip 13 are arranged so as not to overlap each other in plan view. For example, the solid-state imaging element 11 has a layout in which the opening 23 and the backfill portion 35 are adjacent to each other in plan view. As a result, the solid-state imaging element 11 can reduce parasitic resistance and parasitic capacitance, for example.
The solid-state imaging element 11 has a layout in which each I/O circuit 34 is arranged at a position not overlapping the corresponding opening 23 in plan view, that is, the I/O circuit 34 overlaps the backfill portion 35 adjacent to the opening 23, for example. As a result, for example, the influence of wire bonding on the aluminum pad 21 does not reach the I/O circuit 34, and damage to the I/O circuit 34 can be avoided.
The solid-state imaging element 11 has a layout in which the dummy patterns 33 are arranged in the opening region which is formed in each aluminum pad 31 such that an area overlapping the opening 23 in plan view is opened. As described above, providing the dummy patterns 33 immediately below the opening 23 enables improvement in wire bond resistance of the solid-state imaging element 11 as compared with a structure in which the dummy patterns 33 are not provided, so that a more conforming product can be manufactured.
<Manufacturing Method of Solid-State Imaging Element>
A manufacturing method of the solid-state imaging element 11 will be described with reference to
In the first step, as illustrated in the first stage of
In the second step, as illustrated in the second stage of
For example, in a case where the logic chip 13 is determined to be a conforming product as a result of the KGD inspection, in the third step, as illustrated in the third stage of
In the fourth step, as illustrated in the fourth stage of
Thereafter, for example, a step of partially opening the aluminum pad 21 by digging the wiring layer of the sensor chip 12 to form the opening 23 for wire bonding is performed, and the solid-state imaging element 11 is manufactured.
By the manufacturing method as described above, it is possible to manufacture the solid-state imaging element 11 that is a conforming product.
<Second Configuration Example of Solid-State Imaging Element>
As illustrated in
As illustrated in
In the memory chip 14, for example, a memory (not illustrated) configured to temporarily store pixel data acquired by the sensor chip 12 is provided, and an aluminum pad 51, contact electrodes 52, and an I/O circuit 53 are provided.
The aluminum pad 51 is used for inspection for guaranteeing KGD for the memory chip 14. For example, in the inspection, an opening is provided for electrical connection to the aluminum pad 51, and a backfill portion 54 is provided by backfilling the opening after the inspection. Furthermore, when the memory chip 14 is dug to form the opening (not illustrated), a recess 55 corresponding to the shape of the opening is formed in the aluminum pad 51.
The aluminum pad 51 is also used for electrical connection with the logic chip 13A. For example, the contact electrodes 52 are connected to the aluminum pad 51 at a plurality of locations so as to correspond to the respective contact electrodes 39 of the logic chip 13A in plan view.
The contact electrodes 52 are electrodes for electrically connecting the memory chip 14 to the logic chip 13A, and are electrically and mechanically bonded using bonding (Cu—Cu direct bonding) of the same material on each exposed surface.
The I/O circuit 53 is a circuit including a transistor, wiring, and the like configured to control input and output of a signal to and from the solid-state imaging element 11A, and is preferably disposed so as not to be immediately below wire bonding applied to the aluminum pad 21.
The solid-state imaging element 11A is configured as described above, and a more conforming product can be manufactured similarly to the solid-state imaging element 11.
<Configuration Example of Electronic Apparatus>
The solid-state imaging element 11 as described above can be applied to various electronic apparatuses such as an imaging system such as a digital still camera or a digital video camera, a mobile phone having an imaging function, or another apparatus having an imaging function, for example.
As illustrated in
The optical system 102 includes one or a plurality of lenses, guides image light (incident light) from a subject to the imaging element 103, and forms an image on a light receiving surface (sensor unit) of the imaging element 103.
As the imaging element 103, the above-described solid-state imaging element 11 is applied. Electrons are accumulated in the imaging element 103 for a certain period according to an image formed on the light receiving surface via the optical system 102. Then, a signal corresponding to the electrons accumulated in the imaging element 103 is supplied to the signal processing circuit 104.
The signal processing circuit 104 performs various types of signal processing on the pixel signal output from the imaging element 103. An image (image data) obtained by performing signal processing by the signal processing circuit 104 is supplied to and displayed on the monitor 105, or supplied to and stored (recorded) in the memory 106.
In the imaging device 101 configured as described above, by applying the above-described solid-state imaging element 11, for example, a solid-state imaging element 11 that is a more conforming product can be used, and an image can be reliably captured.
<Usage Example of Image Sensor>
The above-described image sensor can be used in various cases of sensing light such as visible light, infrared light, ultraviolet light, and X-rays as described below, for example.
<Combination Examples of Configurations>
Note that the present technology can also have the following configurations.
(1)
A solid-state imaging element including:
(2)
The solid-state imaging element according to (1) described above, in which the first semiconductor substrate and the second semiconductor substrate are layered in units of chips after inspection for guaranteeing known good die (KGD) is performed on each of the first semiconductor substrate and the second semiconductor substrate.
(3)
The solid-state imaging element according to (1) or (2) described above, in which
(4)
The solid-state imaging element according to (3) described above, in which
(5)
The solid-state imaging element according to (3) or (4) described above, in which
(6)
The solid-state imaging element according to (5) described above, in which the semiconductor circuit is disposed at a position overlapping the backfill portion in plan view.
(7)
The solid-state imaging element according to any one of (1) to (6) described above, in which the first electrode and the second electrode are electrically and mechanically connected to each other by using bonding of the same material.
(8)
The solid-state imaging element according to any one of (1) to (7) described above, further including:
(9)
A manufacturing method of a solid-state imaging element including a first semiconductor substrate provided with a first pad used for connection with the outside, separately from a dedicated pad used for inspection in a manufacturing process, and a second semiconductor substrate provided with a second pad used for inspection in a manufacturing process, the manufacturing method including:
(10)
An electronic apparatus including a solid-state imaging element, the solid-state imaging element including:
Note that the present embodiments are not limited to the above-described embodiments, and various modifications can be made in a range without departing from the gist of the present disclosure. Furthermore, the effects described in the present specification are merely examples and are not limited, and other effects may be provided.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-193097 | Nov 2020 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2021/040800 | 11/5/2021 | WO |