Patent Application
20170288041
The present disclosure generally relates to the fabrication of semiconductor devices, and, more particularly, to a method for forming a doped region in a fin using a variable thickness spacer and the resulting device.
In modern integrated circuits, such as microprocessors, storage devices and the like, a very large number of circuit elements, especially transistors, are provided on a restricted chip area. Transistors come in a variety of shapes and forms, e.g., planar transistors, FinFET transistors, nanowire devices, etc. The transistors are typically either NMOS (NFET) or PMOS (PFET) type devices wherein the “N” and “P” designation is based upon the type of dopants used to create the source/drain regions of the devices. So-called CMOS (Complementary Metal Oxide Semiconductor) technology or products refers to integrated circuit products that are manufactured using both NMOS and PMOS transistor devices. Irrespective of the physical configuration of the transistor device, each device comprises drain and source regions and a gate electrode structure positioned above and between the source/drain regions. Upon application of an appropriate control voltage to the gate electrode, a conductive channel region forms between the drain region and the source region.
In some applications, fins for FinFET devices are formed such that the fin is vertically spaced apart from and above the substrate, with an isolation material positioned between the fin and the substrate.
Various implant procedures are employed to define dopant profiles in the FinFET device 100. The three-dimensional structure of the FinFET device 100 provides unique issues regarding implantation efficacy. Spacers, such as the sidewall spacers 120, are used to tailor the dopant profiles. Although not illustrated in
The present disclosure is directed to various methods and resulting devices that may avoid, or at least reduce, the effects of one or more of the problems identified above.
The 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 methods of forming semiconductor devices. A method includes, among other things, forming a fin in a semiconductor substrate. An isolation structure is formed adjacent the fin. A first portion of the fin extends above the isolation structure. A gate electrode is formed above the first portion of the fin. A fin spacer is formed on the first portion of the fin. The fin spacer covers less than 50% of a height of the first portion of the fin. An implantation process is performed in the presence of the fin spacer to form a doped region in the first portion of the fin.
Another method includes forming a fin in a semiconductor substrate. An isolation structure is formed adjacent the fin. A first portion of the fin extends above the isolation structure. A gate insulation layer is formed above the first portion of the fin. A gate electrode is formed above the gate insulation layer. A spacer layer is formed above the gate electrode and the fin. The spacer layer is etched to define a fin spacer on the first portion of the fin and a gate spacer on the gate electrode. The fin spacer covers less than 50% of a height of the first portion of the fin. A tilted implantation process is performed in the presence of the fin spacer to form a doped region in the first portion of the fin.
A device includes a fin defined in a semiconductor substrate. An isolation structure is positioned adjacent the fin. A first portion of the fin extends above the isolation structure. A gate electrode is positioned above the first portion of the fin. A fin spacer is positioned on the first portion of the fin. The fin spacer covers less than 50% of a height of the first portion of the fin. A gate spacer is positioned on the gate electrode. A doped region is defined in the first portion of the fin. At least a portion of the doped region is positioned laterally adjacent the fin spacer.
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.
Various 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 generally relates to various methods of forming a doped region in a finFET device using a variable thickness spacer and the resulting semiconductor devices. 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. With reference to the attached figures, various illustrative embodiments of the methods and devices disclosed herein will now be described in more detail.
The views in
In one illustrative embodiment, a replacement gate technique is used to form the integrated circuit product 200, and the placeholder gate electrode 225 is illustrated prior to the formation of the replacement gate structure. However, the application of the present subject matter is not limited to a replacement gate or “gate-last” technique, but rather, a gate-first technique may also be used, and a conductive gate electrode material may be substituted for the material of the placeholder gate electrode 225.
Additional processes may be performed to complete the fabrication of the integrated circuit product 200, such as the formation of halo regions, source/drain regions, etc. Subsequent metallization layers and interconnect lines and vias may be formed. Other layers of material may be present, but are not depicted in the attached drawings.
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.
