The present disclosure relates to a semiconductor integrated circuit device having stacked semiconductor chips.
As a method for forming a semiconductor integrated circuit on a semiconductor substrate, a standard cell method is known. The standard cell method is a method in which basic units (e.g., inverters, latches, flipflops, and full adders) having specific logical functions are prepared in advance as standard cells, and a plurality of such standard cells are placed on a semiconductor substrate and connected through interconnects, thereby designing an LSI chip.
For higher integration of a semiconductor integrated circuit, it is proposed to use, for standard cells, interconnects laid in a buried interconnect layer, not interconnects laid in a metal interconnect layer formed above transistors as conventionally done.
U.S. Pat. No. 10,170,413 (
In the cited patent documents, however, no disclosure has been made on how to connect signal lines formed in a main chip to the chip back face.
An objective of the present disclosure is providing, in a semiconductor integrated circuit device having stacked semiconductor chips, an easily-manufacturable and reliable configuration of connecting signal lines formed in a main chip to the chip back face.
According to the first mode of the present disclosure, a semiconductor integrated circuit device includes: a first semiconductor chip; and a second semiconductor chip stacked on the first semiconductor chip, wherein a back face of the first semiconductor chip and a principal face of the second semiconductor chip are opposed to each other, the first semiconductor chip includes a plurality of standard cells, a first power line laid in a buried interconnect layer, extending in a first direction and supplying a first power supply voltage to the plurality of standard cells, a second power line laid in the buried interconnect layer, extending in the first direction, placed adjacently to the first power line in a second direction perpendicular to the first direction, and supplying a second power supply voltage to the plurality of standard cells, a third power line laid in the buried interconnect layer, extending in the first direction, placed adjacently to the second power line in the second direction on a side opposite to the first power line, and supplying the first power supply voltage to the plurality of standard cells, a first contact provided between the first power line and the back face of the first semiconductor chip, a second contact provided between the second power line and the back face of the first semiconductor chip, and a third contact provided between a first signal line connected to any of the plurality of standard cells and the back face of the first semiconductor chip, and the third contact has an overlap with the second power line in the second direction and is at a position different from positions of the first and second contacts in the first direction, in planar view.
According to the above mode, the first and second semiconductor chips are stacked one upon the other with the back face of the first semiconductor chip opposed to the principal face of the second semiconductor chip. The first semiconductor chip includes the first, second, and third power lines formed in the buried interconnect layer, extending in the first direction, and adjoining one another in the second direction. The first semiconductor chip also includes the first and second contacts provided between the first and second power lines and the chip back face, and the third contact provided between the signal line and the chip back face. The third contact has an overlap with the second power line in the second direction and is at a position different from the positions of the first and second contacts in the first direction, in planar view. Therefore, the spacing between the third contact and the first and second contacts can be sufficiently secured, and thus, even when the size of the third contact in planar view is made large, the manufacture can be easy and the reliability can be secured.
According to the second mode of the present disclosure, a semiconductor integrated circuit device includes: a first semiconductor chip; and a second semiconductor chip stacked on the first semiconductor chip, wherein a back face of the first semiconductor chip and a principal face of the second semiconductor chip are opposed to each other, the first semiconductor chip includes a plurality of standard cells, a first power line laid in a buried interconnect layer, extending in a first direction and supplying a first power supply voltage to the plurality of standard cells, a second power line laid in the buried interconnect layer, extending in the first direction, placed adjacently to the first power line in a second direction perpendicular to the first direction, and supplying a second power supply voltage to the plurality of standard cells, a third power line laid in the buried interconnect layer, extending in the first direction, placed adjacently to the second power line in the second direction on a side opposite to the first power line, and supplying the first power supply voltage to the plurality of standard cells, a first contact provided between the first power line and the back face of the first semiconductor chip, a second contact provided between the second power line and the back face of the first semiconductor chip, and a third contact provided between a first signal line connected to any of the plurality of standard cells and the back face of the first semiconductor chip, and the third contact has an overlap with the second contact in the second direction and is at a position different from positions of the first and second contacts in the first direction, in planar view.
According to the above mode, the first and second semiconductor chips are stacked one upon the other with the back face of the first semiconductor chip opposed to the principal face of the second semiconductor chip. The first semiconductor chip includes the first, second, and third power lines formed in the buried interconnect layer, extending in the first direction, and adjoining one another in the second direction. The first semiconductor chip also includes the first and second contacts provided between the first and second power lines and the chip back face, and the third contact provided between the signal line and the chip back face. The third contact has an overlap with the second contact in the second direction and is at a position different from the positions of the first and second contacts in the first direction, in planar view. Therefore, the spacing between the third contact and the first and second contacts can be sufficiently secured, and thus even when the size of the third contact in planar view is made large, the manufacture can be easy and the reliability can be secured.
According to the third mode of the present disclosure, a semiconductor integrated circuit device includes: a first semiconductor chip; and a second semiconductor chip stacked on the first semiconductor chip, wherein a back face of the first semiconductor chip and a principal face of the second semiconductor chip are opposed to each other, the first semiconductor chip includes a plurality of standard cells, a first power line laid in a buried interconnect layer, extending in a first direction and supplying a first power supply voltage to the plurality of standard cells, a first contact provided between the first power line and the back face of the first semiconductor chip, and a second contact provided between a first signal line connected to any of the plurality of standard cells and the back face of the first semiconductor chip, and the first power line has a first portion and a second portion apart from each other in the first direction, and the second contact is located between the first portion and the second portion in the first direction and has an overlap with the first power line in a second direction perpendicular to the first direction, in planar view.
According to the above mode, the first and second semiconductor chips are stacked one upon the other with the back face of the first semiconductor chip opposed to the principal face of the second semiconductor chip. The first semiconductor chip includes the first power line formed in the buried interconnect layer, extending in the first direction. The first semiconductor chip also includes the first contact provided between the first power line and the chip back face, and the second contact provided between the signal line and the chip back face. The first power line has the first and second portions apart from each other in the first direction. The second contact is located between the first portion and the second portion in the first direction and has an overlap with the first power line in the second direction perpendicular to the first direction, in planar view. Therefore, even when the plane size of the second contact is made large, shorting between the second contact and the first power line can be avoided, and thus, the manufacture can be easy and the reliability can be secured.
According to the present disclosure, in a semiconductor integrated circuit device having stacked semiconductor chips, it is possible to implement an easily-manufacturable and reliable configuration of connecting signal lines formed in a main chip to the chip back face.
An embodiment of the present disclosure will be described hereinafter with reference to the accompanying drawings. Note that, in the following description, in the plan views such as
In the first semiconductor chip 101, buried power lines 11 supplying VDD to the standard cells SC and buried power lines 12 supplying VSS to the standard cells SC extend in the X direction. The buried power lines 11 and the buried power lines 12 are arranged alternately in the Y direction, and the standard cells SC are each placed between the buried power line 11 and the buried power line 12, receiving VDD from the buried power line 11 and VSS from the buried power line 12.
In the second semiconductor chip 102, power lines 21 supplying VDD and power lines 22 supplying VSS extend in the Y direction in the first metal interconnect layer. The power lines 21 and 22 are each paired, arranged side by side with a predetermined spacing between them in the X direction. A power line 25 supplying VDD and a power line 26 supplying VSS extend in the X direction in the second metal interconnect layer. The power lines 21 are connected to the power line 25 through contacts, and the power lines 22 are connected to the power line 26 through contacts.
In the first semiconductor chip 101, power cells 31 are formed at positions overlapping the power lines 21 and 22 of the second semiconductor chip 102 in planar view. The power cells 31 are arranged in line in the Y direction, and each have a TSV 41 for VDD and a TSV 42 for VSS. The buried power lines 11 of the first semiconductor chip 101 and the power lines 21 of the second semiconductor chip 102 are connected through the TSVs 41. The buried power lines 12 of the first semiconductor chip 101 and the power lines 22 of the second semiconductor chip 102 are connected through the TSVs 42. The configuration of the power cells 31 will be described in detail later.
As is found from the cross-sectional view of
In the block layout of
Also, in the block layout of
Details of the configurations of the standard cells SCA and SCB will be described later.
Note that, in the block layout of
The TSVs 51 and 52 for signal are each placed at a position having an overlap with the buried power line 11 supplying VDD in the Y direction. Also, the TSVs 51 and 52 for signal are each at a position having an overlap with the TSVs 41 for power in the Y direction. Therefore, the buried power line 11 supplying VDD is disconnected at the position of the TSV 51 or 52 for signal. Note that the TSV for signal may otherwise be placed at a position having an overlap with the buried power line 12 supplying VSS in the Y direction and at a position having an overlap with the TSV 42 for power in the Y direction. In this case, the buried power line 12 supplying VSS may be made disconnected at the position of the TSV for signal.
If the size of TSVs can be made small, TSVs may be placed in normal standard cells to correspond to the buried power lines as appropriate. Since this eliminates the necessity of providing exclusive power cells, reduction in the area of the semiconductor integrated circuit device can be achieved. In this case, TSVs may just be arranged so that TSVs for VDD be lined in the Y direction and TSVs for VSS be lined in the Y direction, as in the block layout of
The cell SCA shown in
An M1 interconnect 151 extending in the X direction is formed in a metal interconnect layer (M1) located above the area in which the power line 11 is discontinued. The M1 interconnect 151 electrically connects the first portion 11a and the second portion 11b of the power line 11. With this, it is possible to prevent or reduce problems such as a power supply voltage drop caused by the discontinuity of the power line 11 due to the presence of the TSV 51. Note that, if there occurs no problem such as a power supply voltage drop, for example, the M1 interconnect 151 is not necessarily required.
Also, the cell SCA shown in
In the cell SCA shown in
While the power line 11 supplying VDD is placed in the center in the Y direction in the cell SCA shown in
The cell shown in
The distance of a local interconnect from the back face of the first semiconductor chip 101 is larger than that of a buried interconnect. Therefore, the direct connection of the TSV to the local interconnect without formation of a buried interconnect may raise possibilities of damaging the case of manufacturability and lowering the performance (speed) and the reliability. In this layout example, however, the TSV 51A is formed to have a larger plane size than the TSV 51, whereby reduction in case of manufacturability, performance, and reliability can be curbed.
The cell shown in
The cell shown in
Note that the logic circuit constituted by the cell is not limited to the inverter. Note also that the layout examples shown in the
As described above, according to this embodiment, the first semiconductor chip 101 and the second semiconductor chip 102 are stacked one upon the other with the back face of the first semiconductor chip 101 opposed to the principal face of the second semiconductor chip 102. The first semiconductor chip 101 includes the power lines 11 and 12 formed in the buried interconnect layer, extending in the X direction, and adjoining each other in the Y direction, and also includes the contacts 41 and 42 provided between the power lines 11 and 12 and the chip back face and the contacts 51 and 52 provided between the signal lines and the chip back face. The contacts 51 and 52 each have an overlap with the power line 11 in the Y direction, and are at positions different from the positions of the contacts 41 and 42 in the X direction, in planar view. Also, the contacts 51 and 52 each have an overlap with the contacts 41 in the Y direction, and are at positions different from the positions of the contacts 41 and 42 in the X direction, in planar view. With this, the spacing between the contacts 51 and 52 and the contacts 41 and 42 can be sufficiently secured. Therefore, even when the plane size of the contacts 51 and 52 is made large, the contacts can be manufactured easily and the reliability can be secured.
Also, the power line 11 has the first and second portions 11a and 11b apart from each other in the X direction. The contacts 51 and 52 are each located between the first portion 11a and the second portion 11b in the X direction, and have an overlap with the power line 11 in the Y direction, in planar view. With this, even when the plane size of the contacts 51 and 52 is made large, shorting between the contacts 51 and 52 and the power lines 11 can be avoided. Therefore, the contacts can be manufactured easily and the reliability can be secured.
According to the present disclosure, in a semiconductor integrated circuit device having stacked semiconductor chips, it is possible to implement an easily-manufacturable and reliable configuration of connecting signal lines formed in a main chip to the chip back face. The present disclosure is therefore useful for cost reduction of LSI.
Number | Date | Country | Kind |
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2021-212959 | Dec 2021 | JP | national |
This is a continuation of International Application No. PCT/JP2022/044249 filed on Nov. 30, 2022, which claims priority to Japanese Patent Application No. 2021-212959 filed on Dec. 27, 2021. The entire disclosures of these applications are incorporated by reference herein.
Number | Date | Country | |
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Parent | PCT/JP2022/044249 | Nov 2022 | WO |
Child | 18752353 | US |