SEMICONDUCTOR DEVICES FORMED ON A CONTINUOUS ACTIVE REGION WITH AN ISOLATING CONDUCTIVE STRUCTURE POSITIONED BETWEEN SUCH SEMICONDUCTOR DEVICES, AND METHODS OF MAKING SAME
One illustrative device disclosed herein includes a continuous active region defined in a semiconducting substrate, first and second transistors formed in and above the continuous active region, each of the first and second transistors comprising a plurality of doped regions formed in the continuous active region, a conductive isolating electrode positioned above the continuous active region between the first and second transistors and a power rail conductively coupled to the conductive isolating electrode.
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1. Field of the Invention
Generally, the present disclosure relates to the manufacture of sophisticated semiconductor devices, and, more specifically, to a plurality of semiconductor devices formed in and above a continuous active region and a conductive isolating structure formed above the active region between the devices.
2. Description of the Related Art
The fabrication of advanced integrated circuits, such as CPU's, storage devices, ASIC's (application specific integrated circuits) and the like, requires the formation of a large number of circuit elements in a given chip area according to a specified circuit layout. Field effect transistors (FETs) represent one important type of circuit element that substantially determines performance of the integrated circuits. Field effect transistors are typically either NFET devices or PFET devices. During the fabrication of complex integrated circuits, millions of transistors, e.g., NFET transistors and/or PFET transistors, are formed on a substrate including a crystalline semiconductor layer. A field effect transistor, irrespective of whether an NFET transistor or a PFET transistor is considered, typically comprises so-called PN junctions that are formed by an interface of highly doped regions, referred to as drain and source regions, with a slightly doped or non-doped region, referred to as a channel region, disposed between the highly doped source/drain regions. The channel length of a transistor is generally considered to be the lateral distance between the source/drain regions.
As device dimensions have continued to shrink over recent years, it is becoming more challenging to accurately and repeatedly manufacture integrated circuit products that meet performance criteria established for such integrated circuit products. Typically, semiconductor devices are formed on discrete islands of semiconducting substrate, i.e., active regions that are defined in the substrate by isolation structures. For example,
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With each new technology generation, all dimensions of the integrated circuit product are typically reduced. For example, as device dimensions are reduced, the lateral spacing 39 (see
The present disclosure is directed to a plurality of semiconductor devices formed in and above a continuous active region and a conductive isolating structure formed above the active region between the devices that may avoid, or at least reduce, the effects of one or more of the problems identified above.
SUMMARY OF THE INVENTIONThe following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an exhaustive overview of the invention. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.
Generally, the present disclosure is directed to a device that comprises a plurality of semiconductor devices formed in and above a continuous active region and a conductive isolating structure formed above the active region between the devices, and various methods of making such a device. One illustrative device disclosed herein includes a continuous active region defined in a semiconducting substrate, first and second transistors formed in and above the continuous active region, each of the first and second transistors comprising a plurality of doped regions formed in the continuous active region, a conductive isolating electrode positioned above the continuous active region between the first and second transistors and a power rail conductively coupled to the conductive isolating electrode.
Another illustrative device disclosed herein includes first and second continuous active regions defined in a semiconducting substrate, first and second PFET transistors formed in and above the first continuous active region, and first and second NFET transistors formed in and above the second continuous active region. This embodiment of the device further includes a first conductive isolating electrode positioned above the first continuous active region between the first and second PFET transistors, a first power rail conductively coupled to the first conductive isolating electrode, wherein the first power rail is adapted to be at a logically high voltage level, a second conductive isolating electrode positioned above the second continuous active region between the first and second NFET transistors and a second power rail conductively coupled to the second conductive isolating electrode, wherein the second power rail is adapted to be at a logically low voltage level.
The disclosure may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which:
While the subject matter disclosed herein is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTIONVarious illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
The present subject matter will now be described with reference to the attached figures. Various structures, systems and devices are schematically depicted in the drawings for purposes of explanation only and so as to not obscure the present disclosure with details that are well known to those skilled in the art. Nevertheless, the attached drawings are included to describe and explain illustrative examples of the present disclosure. The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, i.e., a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase.
The present disclosure is directed to a device that comprises a plurality of semiconductor devices formed in and above a continuous active region and a conductive isolating structure formed above the active region between the devices, and various methods of making such a device. As will be readily apparent to those skilled in the art upon a complete reading of the present application, the presently disclosed subject matter may be used with a variety of different devices and technologies, e.g., NFET, PFET, CMOS, etc., and it may be readily employed on a variety of integrated circuit products, including, but not limited to, ASIC's, logic devices, memory devices, etc. With reference to the attached drawings, various illustrative embodiments of the devices and methods disclosed herein will now be described in more detail.
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In one illustrative embodiment disclosed herein, the power rails 140H, 140L and the previously described contacts 190P, 192P, 190N and 192N may all be formed in the so-called local interconnect level of the device 100. That is, the power rails 140H, 140L and the previously described contacts 190P, 192P, 190N and 192N may be formed in a level that is between the device level contacts 175 and the so-called “metal 1” layer that is typically the first general wiring layer formed above the substrate. Further explanation of this unique configuration will be explained in connection with the cross-sectional views “A-A”, “B-B” and “C-C” taken where indicated in
The cross-sectional views “A-A”, “B-B” and “C-C” are taken through the active region 112N (where the NMOS devices 122 are formed) and the power rail 140L. However, the arrangement of the contacts and the power rail depicted in these various views applies equally to the contacts and arrangement for the PMOS devices 120 and the power rail 140H, The cross-sectional view “A-A” is taken through the power rail 140L as indicated. The power rail 140L and the contacts 190N, 192N are formed in the same layer of insulating material 182 (not shown in view “A-A”). The contacts 190N, 192N are depicted with dashed lines as they are positioned behind the power rail 140L in this view. As can be seen, the power rail 140L is positioned above the isolation region 113. Also depicted in the view “A-A” is the so-called metal 1 layer 179 with a connecting via 177 to the power rail 140L. The cross-sectional view “B-B” is taken through the contacts 190N, 192N above the isolation region 113. As can be seen in the view “B-B”, the contact 192N contacts the isolating electrode 150NG. The insulating layer 182 is depicted in this view. The cross-sectional view “C-C” is taken through the contacts 190N above the active region 112N. As can be seen in the view “C-C”, the contacts 190N contact the device level contacts 175. By positioning the power rails 140H, 140L and the various contacts 190P, 192P, 190N and 192N in the so-called local interconnect level of the device 100, various advantages may be realized. Due to this local interconnect arrangement approach, the transistor width can be larger, for example, up to 15-20% larger as compared to prior art arrangements involving connections to the metal 1 layer. This increase in transistor width may result in increased circuit performance, e.g., about a 10-15% increase as compared to prior art devices. The increase in performance is due to the fact that a traditional connection scheme at a level above the local interconnect level requires the width of the transistors to be reduced in order to make room for the connections.
In operation, applying a relatively high voltage to the isolating electrode 150PG via the power rail 140H electrically blocks or isolates the adjacent PFET transistors formed in the continuous active region 112P. Similarly, applying a relatively low voltage to the isolating electrode 150NG via the power rail 140L electrically blocks or isolates the adjacent NFET transistors formed in the continuous active region 112N. In CMOS technology, to reach conduction in a PMOS channel, the voltage applied to the gate of the PMOS device must be smaller than the voltage applied to the source by at least the threshold voltage of the PMOS device. When the applied voltage on the gate of the PMOS device is larger than the voltage applied to the source (or at least a voltage greater than the threshold of the transistor), the PMOS transistor is turned-off, meaning the active regions on both sides of the isolation electrode 150PG become electrically isolated. For an NMOS transistor, when the voltage applied on the gate of an NMOS device is greater than the voltage applied on the source by at least the threshold voltage of the NMOS device, a channel region is established under the gate that electrically connects the source and the drain of the NMOS device. By applying a voltage on the gate of the NMOS device that is less than the voltage applied to the source region (or at least lesser than the threshold voltage of the NMOS transistor), the NMOS transistor is turned-off, i.e., the active regions on both sides of the isolation electrode 150NG become electrically isolated.
In typical cell architecture, the minimum voltage or ground is used to bias the P-well body of the N-type CMOS transistors. The same minimum voltage can be applied to the N-side isolation electrode 150NG to effectively isolate the adjacent NMOS transistors. The maximum voltage is used to bias the N-well body of the P-type transistors in CMOS architecture. The same maximum voltage can be applied to the P-side isolation electrode 150PG to effectively isolate the adjacent PMOS transistors.
The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. For example, the process steps set forth above may be performed in a different order. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below.
Claims
1. A device, comprising:
- a continuous active region defined in a semiconducting substrate:
- first and second transistors formed in and above said continuous active region, each of said first and second transistors comprising a plurality of doped regions formed in said continuous active region and a gate electrode;
- a conductive isolating electrode positioned above said continuous active region between said first and second transistors; and
- a power rail conductively coupled to said conductive isolating electrode.
2. The device of claim 1, wherein said first and second transistors are PFET transistors and wherein said power rail is adapted to be at a logically high voltage level.
3. The device of claim 1, wherein said first and second transistors are NFET transistors and wherein said power rail is adapted to be at a logically low voltage level.
4. The device of claim 1, wherein said conductive isolating electrode extends across an entirety of said continuous active region in a direction parallel to a gate width direction of said first and second transistors.
5. The device of claim 1, wherein said conductive isolating electrode comprises the same structure as said gate electrode of said first and second transistors.
6. The device of claim 1, further comprising a layer of insulating material positioned between said conductive isolating electrode and said continuous active region.
7. The device of claim 1, wherein said conductive isolating electrode is positioned above a space between adjacent doped regions of said first and second transistors.
8. The device of claim 7, wherein said adjacent doped regions are source regions of said first and second transistors.
9. The device of claim 7, wherein said adjacent doped regions are drain regions of said first and second transistors.
10. The device of claim 7, wherein said adjacent doped regions are a source region for one of said first and second transistors and a drain region for the other of said first and second transistors.
11. The device of claim 1, wherein said conductive isolating electrode is conductively coupled to said power rail by a conductive contact structure, and wherein said conductive contact structure and said power rail are positioned in the same layer of insulating material.
12. The device of claim 1, wherein said conductive isolating electrode is conductively coupled to said power rail by a conductive contact structure and wherein said conductive contact structure and said power rail are positioned at a level below a metal 1 wiring level of said device.
13. The device of claim 1, wherein said power rail is positioned in a metal 1 wiring level of said device.
14. A device, comprising:
- first and second continuous active regions defined in a semiconducting substrate;
- first and second PFET transistors formed in and above said first continuous active region, each of said first and second PFET transistors comprising a plurality of P-doped regions formed in said first continuous active region and a gate electrode;
- first and second NFET transistors formed in and above said second continuous active region, each of said first and second NFET transistors comprising a plurality of N-doped regions formed in said second continuous active region and a gate electrode;
- a first conductive isolating electrode positioned above said first continuous active region between said first and second PFET transistors;
- a first power rail conductively coupled to said first conductive isolating electrode, wherein said first power rail is adapted to be at a logically high voltage level;
- a second conductive isolating electrode positioned above said second continuous active region between said first and second NFET transistors; and
- a second power rail conductively coupled to said second conductive isolating electrode, wherein said second power rail is adapted to be at a logically low voltage level.
15. The device of claim 14, wherein said first conductive isolating electrode extends across an entirety of said first continuous active region in a direction parallel to a gate width direction of said first and second PFET transistors and wherein said second conductive isolating electrode extends across an entirety of said second continuous active region in a direction parallel to a gate width direction of said first and second NFET transistors.
16. The device of claim 14, wherein each of said first and second conductive isolating electrodes have a long axis, and wherein the long axis of the first conductive isolating electrode is substantially aligned with the long axis of the second conductive isolating electrode.
17. The device of claim 14, wherein said first isolating gate electrode comprises the same structure as said gate electrode of said first and second PFET transistors.
18. The device of claim 17, wherein said second isolating gate electrode comprises the same structure as said gate electrode of said first and second NFET transistors.
19. The device of claim 14, further comprising a first layer of insulating material positioned between said first conductive isolating electrode and said first continuous active region.
20. The device of claim 19, further comprising a second layer of insulating material positioned between said second conductive isolating electrode and said second continuous active region.
21. The device of claim 14, wherein said first conductive isolating electrode is positioned above a space between adjacent P-doped regions of said first and second PFET transistors.
22. The device of claim 21, wherein said second conductive isolating electrode is positioned above a space between adjacent N-doped regions of said first and second NFET transistors.
23. The device of claim 14, wherein said first PFET transistor and said first NFET transistor share a first common gate electrode structure that extends across both of said first and second continuous active regions and an isolation region between said first and second continuous active regions.
24. The device of claim 23, wherein said second PFET transistor and said second NFET transistor share a second common gate electrode structure that extends across both of said first and second continuous active regions and said isolation region between said first and second continuous active regions.
25. The device of claim 14, wherein said first conductive isolating electrode is conductively coupled to said first power rail by a first conductive contact structure, and wherein said second conductive isolating electrode is conductively coupled to said second power rail by a second conductive contact structure, and wherein said first and second conductive contact structures and said first and second power rails are positioned in the same layer of insulating material.
26. The device of claim 14, wherein said first conductive isolating electrode is conductively coupled to said first power rail by a first conductive contact structure, and wherein said second conductive isolating electrode is conductively coupled to said second power rail by a second conductive contact structure, and wherein said first and second conductive contact structures and said first and second power rails are positioned at a level below a metal 1 wiring level of said device.
27. The device of claim 14, wherein said first and second power rails are positioned in a metal 1 wiring level of said device.
28. A device, comprising:
- first and second continuous active regions defined in a semiconducting substrate, said first and second continuous active regions being separated by an isolation region;
- first and second PFET transistors formed in and above said first continuous active region, each of said first and second PFET transistors comprising a plurality of P-doped regions formed in said first continuous active region;
- first and second NFET transistors formed in and above said second continuous active region, each of said first and second NFET transistors comprising a plurality of N-doped regions formed in said second continuous active region;
- a first common gate electrode structure shared by said first PFET transistor and said first NFET transistor, said first common gate electrode extending across both of said first and second continuous active regions and said isolation region;
- a second common gate electrode structure shared by said second PFET transistor and said second NFET transistor, said second common gate electrode extending across both of said first and second continuous active regions and said isolation region;
- a first conductive isolating electrode positioned above said first continuous active region above a space between adjacent P-doped regions of said first and second PFET transistors;
- a first power rail conductively coupled to said first conductive isolating electrode, wherein said first power rail is adapted to be at a logically high voltage level;
- a second conductive isolating electrode positioned above said second continuous active region above a space between adjacent N-doped regions of said first and second NFET transistors; and
- a second power rail conductively coupled to said second conductive isolating electrode, wherein said second power rail is adapted to be at a logically low voltage level.
29. The device of claim 28, wherein said first conductive isolating electrode extends across an entirety of said first continuous active region in a direction parallel to a gate width direction of said first and second PFET transistors and wherein said second conductive isolating electrode extends across an entirety of said second continuous active region in a direction parallel to a gate width direction of said first and second NFET transistors.
30. The device of claim 28, wherein each of said first and second conductive isolating electrodes have a long axis, and wherein the long axis of the first conductive isolating electrode is substantially aligned with the long axis of the second conductive isolating electrode.
31. The device of claim 28, wherein said first and second isolating gate electrodes comprise the same structure as said first and second common gate electrodes.
32. The device of claim 28, further comprising a first layer of insulating material positioned between said first conductive isolating electrode and said first continuous active region.
33. The device of claim 32, further comprising a second layer of insulating material positioned between said second conductive isolating electrode and said second continuous active region.
34. The device of claim 28, wherein said first conductive isolating electrode is conductively coupled to said first power rail by a first conductive contact structure, and wherein said second conductive isolating electrode is conductively coupled to said second power rail by a second conductive contact structure, and wherein said first and second conductive contact structures and said first and second power rails are positioned in the same layer of insulating material.
35. The device of claim 28, wherein said first conductive isolating electrode is conductively coupled to said first power rail by a first conductive contact structure, and wherein said second conductive isolating electrode is conductively coupled to said second power rail by a second conductive contact structure, and wherein said first and second conductive contact structures and said first and second power rails are positioned at a level below a metal 1 wiring level of said device.
36. The device of claim 28, wherein said first and second power rails are positioned in a metal 1 wiring level of said device.
Type: Application
Filed: Jul 2, 2012
Publication Date: Jan 2, 2014
Applicant: GLOBALFOUNDRIES INC. (Grand Cayman)
Inventors: Mahbub Rashed (Santa Clara, CA), David Doman (Austin, TX), Marc Tarabbia (Pleasant Valley, NY), Irene Lin (Los Altos Hills, CA), Jeff Kim (San Jose, CA), Chinh Nguyen (Austin, TX), Steve Soss (Cornwall, NY), Scott Johnson (Wappingers Falls, NY), Subramani Kengeri (San Jose, CA), Suresh Venkatesan (Malta, NY)
Application Number: 13/539,830
International Classification: H01L 27/088 (20060101); H01L 27/092 (20060101);