PRODUCT COMPRISED OF FINFET DEVICES WITH SINGLE DIFFUSION BREAK ISOLATION STRUCTURES
An integrated circuit product is disclosed that includes a plurality of trenches in a semiconducting substrate that define first, second and third fins, wherein the fins are side-by-side, and wherein the second fin is positioned between the first and third fins, a layer of insulating material in the plurality of trenches such that a desired height of the first, second and third fins is positioned above an upper surface of the layer of insulating material, a recess defined in the second fin that at least partially defines a cavity in the layer of insulating material, an SDB isolation structure in the cavity on the recessed portion of the second fin, wherein the SDB isolation structure has an upper surface that is above the upper surface of the layer of insulating material, and a gate structure for a transistor positioned above the SDB isolation structure.
1. Field of the Invention
Generally, the present disclosure relates to the manufacture of semiconductor devices, and, more specifically, to various examples of an integrated circuit product comprised of FinFET devices with single diffusion break isolation structures, and various methods of making such products.
2. Description of the Related Art
A shallow trench isolation structure (not shown) is formed in the semiconducting substrate 12 around the FinFET device 10 so as to electrically isolate the FinFET device. Traditionally, isolation structures were always the first structures that were formed when manufacturing semiconductor devices. The isolation structures were formed by etching the trenches for the isolation structures and thereafter filling the trenches with the desired insulating material, e.g., silicon dioxide. Thereafter, the isolation structures were masked and the trenches 14 were etched into the substrate 12 so as to define the fins 16. However, as the dimensions of the fins became smaller, problems arose with manufacturing the isolation structures before the fins were formed. As one example, trying to accurately define very small fins in regions that were separated by relatively large isolation regions was difficult due to the non-uniform spacing between various structures on the substrate. One manufacturing technique that is employed in manufacturing FinFET devices is to initially form the trenches 14 in the substrate 12 to define multiple “fins” that extend across the entire wafer or substrate 12, and thereafter remove some of the fins 16 where isolation structures will be formed. Using this type of manufacturing approach, better accuracy and repeatability may be achieved in forming the fins 16 to very small dimensions due to the more uniform environment in which the etching process that forms the trenches 14 is performed.
The size or “footprint” of the fins 16 that are removed so that an isolation structure can be formed may vary in size, i.e., it may be very large (in a relative sense) or very small. In many applications, a section of several adjacent fins, positioned side-by-side, may be removed to make room for a portion of a relatively large isolation structure. In some product designs, only a portion of one single fin may be removed between two adjacent “active” fins to make room for an isolation structure that is to be formed between the two active fins. That is, considering three fins that are formed side-by-side with a uniform gate pitch for all three, a portion of the middle fin may be removed, thereby cutting the middle fin into two active fins. The amount of the middle fin removed in such a situation corresponds approximately to the gate length of a “dummy” gate structure that will be formed in and above the area of the removed portion of the middle fin. Such a configuration is sometimes referred to as a Single Diffusion Break (SDB), since the isolation material that will be formed where the portion of the middle fin is removed is the only means of preventing undesirable current flow between the two active fins that abut the SDB isolation structure.
One prior art fin removal process that is typically referred to as “Fins-cut-First,” will be described with reference to
An alternative method to achieve the prior art device 10 depicted in
One prior art technique that has been employed in an attempt to increase the height of the isolation material under the dummy gate structure 30 between the fins 16X, 16Y is simplistically depicted in
The present disclosure is directed to various examples of an integrated circuit product comprised of FinFET devices with single diffusion break isolation structures, and various methods of making such products, that may solve or reduce 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 various examples of an integrated circuit product comprised of FinFET devices with single diffusion break isolation structures. One illustrative integrated circuit product disclosed herein includes, among other things, a plurality of trenches in a semiconducting substrate that define first, second and third fins in the substrate, wherein the first, second and third fins are positioned side-by-side, and wherein the second fin is positioned between the first and third fins, a layer of insulating material positioned in the plurality of trenches such that a desired height of the first, second and third fins is positioned above an upper surface of the layer of insulating material, a recess defined in the second fin structure that at least partially defines a cavity in the layer of insulating material above the recess in the second fin, an SDB isolation structure positioned in the cavity on the recessed portion of the second fin, wherein the SDB isolation structure has an upper surface that is positioned at a level that is above a level of the upper surface of the layer of insulating material, and a gate structure for a transistor positioned above the SDB isolation structure.
Another illustrative integrated circuit product disclosed herein includes, among other things, a plurality of trenches in a semiconducting substrate that define first, second and third fins in the substrate, wherein the first, second and third fins are positioned side-by-side, and wherein the second fin is positioned between the first and third fins, a layer of silicon dioxide positioned in the plurality of trenches such that a desired height of the first, second and third fins is positioned above an upper surface of the layer of silicon dioxide, a recess defined in the second fin structure that at least partially defines a cavity in the layer of silicon dioxide, an SDB silicon dioxide isolation structure positioned in the cavity on the recessed portion of the second fin, wherein the SDB silicon dioxide isolation structure has an upper surface that is positioned at a level that is above a level of the upper surface of the layer of silicon dioxide and wherein the upper surface of the SDB silicon dioxide isolation structure is approximately level with an upper surface of the second fin positioned on opposite sides of the SDB silicon dioxide isolation structure, and a gate structure for a transistor positioned above the SDB silicon dioxide isolation structure.
Yet another illustrative integrated circuit product disclosed herein includes, among other things, a plurality of trenches in a semiconducting substrate that define first, second and third fins in the substrate, wherein the first, second and third fins are positioned side-by-side, and wherein the second fin is positioned between the first and third fins, a layer of insulating material positioned in the plurality of trenches such that a desired height of the first, second and third fins is positioned above an upper surface of the layer of insulating material, a recess defined in the second fin structure that at least partially defines a cavity in the layer of insulating material, an SDB isolation structure positioned in the cavity on the recessed portion of the second fin, wherein the SDB isolation structure has an upper surface that is positioned at a level that is above a level of the upper surface of the layer of insulating material, the upper surface of the SDB isolation structure is approximately level with an upper surface of the second fin positioned on opposite sides of the SDB isolation structure, and a portion of the SDB isolation structure positioned above the upper surface of the recessed layer of insulating material has a substantially uniform width in a direction that corresponds to a width of the second fin, and a gate structure for a transistor positioned above the SDB isolation structure.
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 various methods for removing selected fins that are formed for FinFET semiconductor devices. As will be readily apparent to those skilled in the art upon a complete reading of the present application, the methods disclosed herein may be employed in manufacturing a variety of different devices, including, but not limited to, logic devices, memory devices, etc. With reference to the attached figures, various illustrative embodiments of the methods and devices disclosed herein will now be described in more detail.
Accordingly,
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. Note that the use of terms, such as “first,” “second,” “third” or “fourth” to describe various processes or structures in this specification and in the attached claims is only used as a shorthand reference to such steps/structures and does not necessarily imply that such steps/structures are performed/formed in that ordered sequence. Of course, depending upon the exact claim language, an ordered sequence of such processes may or may not be required. Accordingly, the protection sought herein is as set forth in the claims below.
Claims
1. An integrated circuit product, comprising:
- a plurality of trenches in a semiconducting substrate that define first, second and third fins in said substrate, wherein said first, second and third fins are positioned side-by-side, and wherein said second fin is positioned between said first and third fins;
- a layer of insulating material positioned in said plurality of trenches such that a desired height of said first, second and third fins is positioned above an upper surface of said layer of insulating material;
- a recess defined in said second fin structure that at least partially defines a cavity in said layer of insulating material;
- an SDB isolation structure positioned in said cavity on said recessed portion of said second fin, wherein said SDB isolation structure has an upper surface that is positioned at a level that is above a level of said upper surface of said layer of insulating material; and
- a gate structure for a transistor positioned above said SDB isolation structure.
2. The product of claim 1, wherein said SDB isolation structure and said layer of insulating material are both made of silicon dioxide.
3. The product of claim 1, wherein said upper surface of said SDB isolation structure is approximately level with an upper surface of said second fin positioned on opposite sides of said SDB isolation structure.
4. The product of claim 1, wherein a portion of said SDB isolation structure positioned above said upper surface of said recessed layer of insulating material has a substantially uniform width in a direction that corresponds to a width of said second fin.
5. The product of claim 1, wherein said first, second and third fins are arranged on a single fin pitch pattern.
6. An integrated circuit product, comprising:
- a plurality of trenches in a semiconducting substrate that define first, second and third fins in said substrate, wherein said first, second and third fins are positioned side-by-side, and wherein said second fin is positioned between said first and third fins;
- a layer of silicon dioxide positioned in said plurality of trenches such that a desired height of said first, second and third fins is positioned above an upper surface of said layer of silicon dioxide;
- a recess defined in said second fin structure that at least partially defines a cavity in said layer of silicon dioxide;
- an SDB silicon dioxide isolation structure positioned in said cavity on said recessed portion of said second fin, wherein said SDB silicon dioxide isolation structure has an upper surface that is positioned at a level that is above a level of said upper surface of said layer of silicon dioxide and wherein said upper surface of said SDB silicon dioxide isolation structure is approximately level with an upper surface of said second fin positioned on opposite sides of said SDB silicon dioxide isolation structure; and
- a gate structure for a transistor positioned above said SDB silicon dioxide isolation structure.
7. The product of claim 6, wherein a portion of said SDB silicon dioxide isolation structure positioned above said upper surface of said recessed layer of insulating material has a substantially uniform width in a direction that corresponds to a width of said second fin.
8. The product of claim 7, wherein said first, second and third fins are arranged on a single fin pitch pattern.
9. An integrated circuit product, comprising:
- a plurality of trenches in a semiconducting substrate that define first, second and third fins in said substrate, wherein said first, second and third fins are positioned side-by-side, and wherein said second fin is positioned between said first and third fins;
- a layer of insulating material positioned in said plurality of trenches such that a desired height of said first, second and third fins is positioned above an upper surface of said layer of insulating material;
- a recess defined in said second fin structure that at least partially defines a cavity in said layer of insulating material;
- an SDB isolation structure positioned in said cavity on said recessed portion of said second fin, wherein said SDB isolation structure comprises: an upper surface that is positioned at a level that is above a level of said upper surface of said layer of insulating material; said upper surface of said SDB isolation structure is approximately level with an upper surface of said second fin positioned on opposite sides of said SDB isolation structure; and a portion of said SDB isolation structure positioned above said upper surface of said recessed layer of insulating material has a substantially uniform width in a direction that corresponds to a width of said second fin; and
- a gate structure for a transistor positioned above said SDB isolation structure.
10. The product of claim 9, wherein said SDB isolation structure and said layer of insulating material are both made of silicon dioxide.
11. The product of claim 9, wherein said first, second and third fins are arranged on a single fin pitch pattern.
Type: Application
Filed: Aug 11, 2015
Publication Date: Feb 18, 2016
Inventors: Xusheng Wu (Ballston Lake, NY), Changyong Xiao (Mechanicville, NY), Wanxun He (Mechanicville, NY), Hongliang Shen (Ballston Lake, NY)
Application Number: 14/823,319