METHODS OF FORMING GATE STRUCTURES FOR FINFET DEVICES AND THE RESULTING SEMICONDUCTOR PRODUCTS
A transistor device includes first and second spaced-apart active regions positioned in a semiconductor substrate, each of the respective first and second spaced-apart active regions having at least one fin. First and second spaced-apart gate structures are positioned above the respective first and second active regions, each of the first and second gate structures having end surfaces. A gate separation structure is positioned between the first and second spaced-apart gate structures, wherein first and second opposing surfaces of the gate separation structure abut an entirety of the respective end surfaces of the first and second spaced-apart gate structures, and wherein an upper surface of the gate separation structure is positioned at a greater height level above the semiconductor substrate than an upper surface of the at least one fin of each of the respective first and second spaced-apart active regions.
1. Field of the Disclosure
Generally, the present disclosure relates to the fabrication of integrated circuits, and, more particularly, to various methods of forming gate structures for FinFET devices and the resulting semiconductor devices.
2. Description of the Related Art
In modern integrated circuits, such as microprocessors, storage devices and the like, a very large number of circuit elements, especially transistors, are provided and operated on a restricted chip area. Immense progress has been made over recent decades with respect to increased performance and reduced feature sizes of circuit elements, such as transistors. However, the ongoing demand for enhanced functionality of electronic devices forces semiconductor manufacturers to steadily reduce the dimensions of the circuit elements and to increase the operating speed of the circuit elements. The continuing scaling of feature sizes, however, involves great efforts in redesigning process techniques and developing new process strategies and tools so as to comply with new design rules. Generally, in complex circuitry including complex logic portions, MOS technology is presently a preferred manufacturing technique in view of device performance and/or power consumption and/or cost efficiency. In integrated circuits including logic portions fabricated by MOS technology, field effect transistors (FETs) are provided that are typically operated in a switched mode, that is, these devices exhibit a highly conductive state (on-state) and a high impedance state (off-state). The state of the field effect transistor is controlled by a gate electrode, which controls, upon application of an appropriate control voltage, the conductivity of a channel region formed between a drain region and a source region.
To improve the operating speed of FETs, and to increase the density of FETs on an integrated circuit device, device designers have greatly reduced the physical size of FETs over the years. More specifically, the channel length of FETs has been significantly decreased, which has resulted in improving the switching speed of FETs. However, decreasing the channel length of a FET also decreases the distance between the source region and the drain region. In some cases, this decrease in the separation between the source and the drain makes it difficult to efficiently inhibit the electrical potential of the source region and the channel from being adversely affected by the electrical potential of the drain. This is sometimes referred to as a so-called short channel effect, wherein the characteristic of the FET as an active switch is degraded.
In contrast to a FET, which has a planar structure, a so-called FinFET device has a three-dimensional (3D) structure.
In the FinFET device A, the gate structure D may enclose both sides and the upper surface of all or a portion of the fins C to form a tri-gate structure so as to use a channel having a three-dimensional structure instead of a planar structure. In some cases, an insulating cap layer (not shown), e.g., silicon nitride, is positioned at the top of the fins C and the FinFET device only has a dual-gate structure (sidewalls only). Unlike a planar FET, in a FinFET device, a channel is formed perpendicular to a surface of the semiconducting substrate so as to reduce the physical size of the semiconductor device. Also, in a FinFET, the junction capacitance at the drain region of the device is greatly reduced, which tends to significantly reduce short channel effects. When an appropriate voltage is applied to the gate electrode of a FinFET device, the surfaces (and the inner portion near the surface) of the fins C, i.e., the vertically oriented sidewalls and the top upper surface of the fin, form a surface inversion layer or a volume inversion layer that contributes to current conduction. In a FinFET device, the “channel-width” is estimated to be about two times (2×) the vertical fin-height plus the width of the top surface of the fin, i.e., the fin width. Multiple fins can be formed in the same foot-print as that of a planar transistor device. Accordingly, for a given plot space (or foot-print), FinFETs tend to be able to generate significantly higher drive current density than planar transistor devices. Additionally, the leakage current of FinFET devices after the device is turned “OFF” is significantly reduced as compared to the leakage current of planar FETs, due to the superior gate electrostatic control of the “fin” channel on FinFET devices. In short, the 3D structure of a FinFET device is a superior MOSFET structure as compared to that of a planar FET, especially in the 20 nm CMOS technology node and beyond. The gate structures D for such FinFET devices may be manufactured using so-called “gate-first” or “replacement gate” (gate-last) manufacturing techniques.
Over recent years, due to the reduced dimensions of the transistor devices, the operating speed of the circuit components has been increased with every new device generation, and the “packing density,” i.e., the number of transistor devices per unit area, in such products has also increased during that time. As a result of such increased packing densities, the physical space between adjacent devices has become very small, which can lead to some problems in manufacturing.
The present disclosure is directed to various methods of forming gate structures for FinFET devices and the resulting semiconductor devices that may avoid, or at least reduce, the effects of one or more of the problems identified above.
SUMMARY OF THE DISCLOSUREThe following presents a simplified summary of the disclosure in order to provide a basic understanding of some aspects of the subject matter that is described in further detail below. This summary is not an exhaustive overview of the disclosure, nor is it intended to identify key or critical elements of the subject matter disclosed here. 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 methods of forming gate structures for FinFET devices and the resulting semiconductor devices. One illustrative transistor device disclosed herein includes, among other things, first and second spaced-apart active regions positioned in a semiconductor substrate, each of the respective first and second spaced-apart active regions having at least one fin. Furthermore, first and second spaced-apart gate structures are positioned above the respective first and second active regions, each of the first and second gate structures having end surfaces. Additionally, a gate separation structure is positioned between the first and second spaced-apart gate structures, wherein first and second opposing surfaces of the gate separation structure abut an entirety of the respective end surfaces of the first and second spaced-apart gate structures, and wherein an upper surface of the gate separation structure is positioned at a greater height level above the semiconductor substrate than an upper surface of the at least one fin of each of the respective first and second spaced-apart active regions.
Yet another illustrative transistor device of the present disclosure includes first and second spaced-apart active regions positioned in a semiconductor substrate, each of the respective first and second spaced-apart active regions having at least one fin. The exemplary transistor device further includes, among other things, first and second spaced-apart gate structures positioned above and extending across the at least one fin of each of the respective first and second spaced-apart active regions, each of the first and second spaced-apart gate structures having side surfaces, wherein the first gate structure is oriented parallel to the second gate structure. Furthermore, a gate separation structure is positioned between adjacent side surfaces of the first and second spaced-apart gate structures, wherein an upper surface of the gate separation structure is positioned at a greater height level above the semiconductor substrate than an upper surface of the at least one fin of each of the respective first and second spaced-apart active regions.
In a further exemplary embodiment, a transistor device is disclosed that includes a first active region positioned in a semiconductor substrate and having a first fin, and a first gate structure positioned above the first active region and extending across the first fin, the first gate structure having a first end surface and a first side surface. The disclosed transistor device also includes, among other things, a second active region positioned in the semiconductor substrate and spaced apart from the first active region, the second active region having a second fin, and a second gate structure positioned above the second active region and extending across the second fin, the second gate structure having a second end surface and a second side surface that is positioned laterally adjacent to and spaced apart from the first side surface of the first gate structure, wherein the second gate structure is oriented parallel to the first gate structure. Additionally, a third active region is positioned in the semiconductor substrate and spaced apart from the first active region, the third active region having a third fin, and a third gate structure is positioned above the third active region and extends across the third fin, the third gate structure having a third side surface and a third end surface that is positioned laterally adjacent to and spaced apart from the first end surface of the first gate structure, wherein the third gate structure is oriented parallel to the first and second gate structures. The illustrative transistor device further includes a fourth active region positioned in the semiconductor substrate and spaced apart from the second and third active regions, the fourth active region comprising a fourth fin, and a fourth gate structure positioned above the fourth active region and extending across the fourth fin, the fourth gate structure having a fourth end surface that is positioned laterally adjacent to and spaced apart from the second end surface of the second gate structure and a fourth side surface that is positioned laterally adjacent to and spaced apart from the third side surface of the third gate structure, wherein the fourth gate structure is oriented parallel to the first, second and third gate structures. Moreover, the device also includes a gate separation structure having a substantially planar upper surface that is positioned at a greater height level above the semiconductor substrate than an upper surface of each of the first, second, third and fourth fins. The gate separation structure includes, among other things, a first portion positioned between the laterally adjacent first and second side surfaces of the respective first and second gate structures, a second portion positioned between the laterally adjacent first and third end surfaces of the respective first and third gate structures, a third portion positioned between the laterally adjacent third and fourth side surfaces of the respective third and fourth gate structures, and a fourth portion positioned between the laterally adjacent second and fourth side surfaces of the respective second and fourth gate structures.
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.
DETAILED DESCRIPTIONVarious illustrative embodiments of the present subject matter 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 systems, structures 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 generally relates to various methods of forming gate structures for FinFET devices and the resulting semiconductor devices. Moreover, as will be readily apparent to those skilled in the art upon a complete reading of the present application, the present method is applicable to a variety of devices, including, but not limited to, logic devices, memory devices, etc., and the methods disclosed herein may be employed to form N-type or P-type semiconductor devices. The methods and devices disclosed herein may be employed in manufacturing products using a variety of technologies, e.g., NMOS, PMOS, CMOS, etc., and they may be employed in manufacturing a variety of different devices, e.g., memory devices, logic devices, ASICs, etc. With reference to the attached figures, various illustrative embodiments of the methods and devices disclosed herein will now be described in more detail.
With continuing reference to
The next series of process operations involves formation of a replacement gate structure of the devices.
As will be appreciated and understood by those skilled in the art after a complete reading of the present application, there are several novel methods and devices disclosed herein.
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. A transistor device, comprising:
- first and second spaced-apart active regions positioned in a semiconductor substrate, each of said respective first and second spaced-apart active regions comprising at least one fin;
- first and second spaced-apart gate structures positioned above said respective first and second active regions, respectively, each of said first and second gate structures comprising end surfaces; and
- a gate separation structure positioned between said first and second spaced-apart gate structures, wherein first and second opposing surfaces of said gate separation structure abut an entirety of said respective end surfaces of said first and second spaced-apart gate structures, and wherein an upper surface of said gate separation structure is positioned at a greater height level above said semiconductor substrate than an upper surface of said at least one fin comprising each of said respective first and second spaced-apart active regions.
2. The transistor device of claim 1, wherein said upper surface of said gate separation structure is positioned at a height level above said semiconductor substrate that is approximately even with a height level of an upper surface of an uppermost conductive material of said first and second gate structures.
3. The transistor device of claim 1, further comprising;
- a first sidewall spacer positioned adjacent opposing side surfaces of said gate separation structure; and
- an epitaxial semiconductor material positioned on said at least one fin comprising each of said respective first and second spaced-apart active regions, said epitaxial semiconductor material abutting said first sidewall spacer.
4. The transistor device of claim 3, further comprising a second sidewall spacer positioned adjacent sidewall surfaces of each of said first and second spaced-apart gate structures, said epitaxial semiconductor material further abutting said second sidewall spacers.
5. The transistor device of claim 1, further comprising:
- a third active region positioned in said semiconductor substrate and spaced apart from said first active region, said third active region comprising at least one fin; and
- a third gate structure positioned above said third active region, said third gate structure being oriented substantially parallel to said first gate structure, wherein said first and third gate structures have side surfaces, and wherein a portion of said gate separation structure is positioned in an area between said side surfaces of said first and third gate structures.
6. The transistor device of claim 1, wherein each of said first and second spaced-apart gate structures comprise a high-k gate insulation layer and one or more metal layers positioned above said high-k gate insulation layer.
7. A transistor device, comprising:
- first and second spaced-apart active regions positioned in a semiconductor substrate, each of said respective first and second spaced-apart active regions comprising at least one fin;
- first and second spaced-apart gate structures positioned above and extending across said at least one fin of each of said respective first and second spaced-apart active regions, each of said first and second spaced-apart gate structures comprising side surfaces, wherein said first gate structure is oriented parallel to said second gate structure; and
- a gate separation structure positioned between adjacent side surfaces of said first and second spaced-apart gate structures, wherein an upper surface of said gate separation structure is positioned at a greater height level above said semiconductor substrate than an upper surface of said at least one fin comprising each of said respective first and second spaced-apart active regions.
8. The transistor device of claim 7, wherein said upper surface of said gate separation structure is positioned at a height level above said semiconductor substrate that is approximately even with a height level of an upper surface of an uppermost conductive material of said first and second gate structures.
9. The transistor device of claim 7, further comprising:
- a first sidewall spacer positioned adjacent opposing side surfaces of said gate separation structure; and
- an epitaxial semiconductor material positioned on said at least one fin comprising each of said respective first and second spaced-apart active regions, said epitaxial semiconductor material abutting said first sidewall spacer.
10. The transistor device of claim 9, further comprising a second sidewall spacer positioned adjacent sidewall surfaces of each of said first and second spaced-apart gate structures, said epitaxial semiconductor material further abutting said second sidewall spacers.
11. The transistor device of claim 7, further comprising:
- a third active region positioned in said semiconductor substrate and spaced apart from said first active region, said third active region comprising at least one fin; and
- a third gate structure positioned above said third active region and extending across said at least one fin of said third active region, said third gate structure being oriented substantially parallel to each of said first and second spaced-apart gate structures, wherein said first and third gate structures have end surfaces and wherein a portion of said gate separation structure extends between and abuts an entirety of said end surfaces of said first and third gate structures.
12. The transistor device of claim 11, further comprising a fourth active region positioned in said semiconductor substrate and spaced apart from each of said second and third active regions, said fourth active region comprising at least one fin, wherein said third gate structure has a side surface that is positioned laterally adjacent to and spaced apart from a side surface of a gate structure extending across said at least one fin of said fourth active region, and wherein a further portion of said gate separation structure is positioned between said laterally adjacent side surfaces of said fourth gate structure and said gate structure extending across said at least one fin of said fourth active region.
13. The transistor device of claim 12, wherein said gate structure extending across said at least one fin of said fourth active region comprises a portion of said second gate structure that extends continuously from said second active region and across said fourth active region.
14. The transistor device of claim 12, wherein said gate separation structure has a substantially T-shaped configuration when viewed from above.
15. The transistor device of claim 7, wherein each of said first and second spaced-apart gate structures comprise a high-k gate insulation layer and one or more metal layers positioned above said high-k gate insulation layer.
16. A transistor device, comprising:
- a first active region positioned in a semiconductor substrate and comprising a first fin;
- a first gate structure positioned above said first active region and extending across said first fin, said first gate structure having a first end surface and a first side surface;
- a second active region positioned in said semiconductor substrate and spaced apart from said first active region, said second active region comprising a second fin;
- a second gate structure positioned above said second active region and extending across said second fin, said second gate structure having a second end surface and a second side surface that is positioned laterally adjacent to and spaced apart from said first side surface of said first gate structure, wherein said second gate structure is oriented parallel to said first gate structure;
- a third active region positioned in said semiconductor substrate and spaced apart from said first active region, said third active region comprising a third fin;
- a third gate structure positioned above said third active region and extending across said third fin, said third gate structure having a third side surface and a third end surface that is positioned laterally adjacent to and spaced apart from said first end surface of said first gate structure, wherein said third gate structure is oriented parallel to said first and second gate structures;
- a fourth active region positioned in said semiconductor substrate and spaced apart from said second and third active regions, said fourth active region comprising a fourth fin;
- a fourth gate structure positioned above said fourth active region and extending across said fourth fin, said fourth gate structure having a fourth end surface that is positioned laterally adjacent to and spaced apart from said second end surface of said second gate structure and a fourth side surface that is positioned laterally adjacent to and spaced apart from said third side surface of said third gate structure, wherein said fourth gate structure is oriented parallel to said first, second, and third gate structures;
- a gate separation structure having a substantially planar upper surface that is positioned at a greater height level above said semiconductor substrate than an upper surface of each of said first, second, third and fourth fins, said gate separation structure comprising: a first portion positioned between said laterally adjacent first and second side surfaces of said respective first and second gate structures; a second portion positioned between said laterally adjacent first and third end surfaces of said respective first and third gate structures; a third portion positioned between said laterally adjacent third and fourth side surfaces of said respective third and fourth gate structures; and a fourth portion positioned between said laterally adjacent second and fourth side surfaces of said respective second and fourth gate structures.
17. The transistor device of claim 16, wherein said gate separation structure has a substantially cross-shaped configuration when viewed from above.
18. The transistor device of claim 16, wherein said second portion of said gate separation structure abuts an entirety of said first and third end surfaces of said respective first and third gate structures, and wherein said fourth portion of said gate separation structure abuts an entirety of said second and fourth end surfaces of said respective second and fourth gate structures.
19. The transistor device of claim 16, further comprising:
- a first sidewall spacer positioned adjacent sidewall surfaces of said gate separation structure;
- a second sidewall spacer positioned adjacent sidewall surfaces of each of said first, second, third and fourth gate structures; and
- an epitaxial semiconductor material positioned on said first, second, third and fourth fins, said epitaxial semiconductor material abutting said first and second sidewall spacers.
20. The transistor device of claim 16, wherein each of said first, second, third and fourth gate structures comprise a high-k gate insulation layer and one or more metal layers positioned above said high-k gate insulation layer.
Type: Application
Filed: Nov 17, 2015
Publication Date: Mar 10, 2016
Inventors: Ruilong Xie (Niskayuna, NY), Shom Ponoth (Gaithersburg, MD), Juntao Li (Cohoes, NY)
Application Number: 14/943,522