THERMAL-AWARE FINFET DESIGN
20170271499 · 2017-09-21
Inventors
Cpc classification
H01L29/6681
ELECTRICITY
H01L29/1054
ELECTRICITY
H01L29/1033
ELECTRICITY
H01L29/16
ELECTRICITY
H01L29/20
ELECTRICITY
H01L29/785
ELECTRICITY
H01L29/66795
ELECTRICITY
International classification
H01L21/02
ELECTRICITY
H01L29/10
ELECTRICITY
H01L23/373
ELECTRICITY
H01L29/66
ELECTRICITY
H01L29/20
ELECTRICITY
H01L29/16
ELECTRICITY
Abstract
According to various aspects, a thermal-aware finned field-effect transistor (FinFET) may have a design that can substantially reduce hot spot temperatures and resolve other self-heating problems. More particularly, the FinFET design may use aluminum nitride (AlN) fins that can provide a main thermal exit and a source, drain, and channel formed from materials that can spread or dissipate heat, wherein AlN has a high thermal conductivity compared to silicon such that using AlN to form the fins may substantially increase heat flux to a silicon substrate relative to silicon fins. Furthermore, thermal-efficient materials may be used to form the source, drain, and channel structures to further spread heat and decrease hot spot temperatures.
Claims
1. A thermal-aware finned field-effect transistor (FinFET), comprising: a source stack formed on a substrate; a drain stack formed on the substrate; and a gate stack formed on the substrate in a channel region disposed between the source stack and the drain stack, wherein the gate stack comprises: multiple channel structures intersecting the source stack and the drain stack, wherein the multiple channel structures comprise a lower-most channel structure formed on the substrate; and thermal-efficient layers formed around the multiple channel structures, wherein the thermal-efficient layers are formed from a high-k dielectric material and a material having a high thermal conductivity.
2. The thermal-aware FinFET recited in claim 1, wherein the multiple channel structures are formed from a material having a lattice matched to the material in the thermal-efficient layers having the high thermal conductivity.
3. The thermal-aware FinFET recited in claim 2, wherein the thermal-efficient layers comprise a first layer formed on the lower-most channel structure through epitaxial growth and at least one second layer having one of the multiple channel structures formed thereon through epitaxial growth.
4. The thermal-aware FinFET recited in claim 2, wherein the material in the thermal-efficient layers having the high thermal conductivity comprises one or more of aluminum nitride or beryllium oxide.
5. The thermal-aware FinFET recited in claim 4, wherein the material used in the multiple channel structures with the matching lattice comprises one or more of silicon, indium gallium arsenide, silicon-germanium, or a III-V nitride.
6. The thermal-aware FinFET recited in claim 1, wherein the material having the high thermal conductivity causes heat to flow downward into the substrate and upward to a metal gate formed atop the gate stack.
7. The thermal-aware FinFET recited in claim 6, wherein the multiple channel structures intersecting the source stack and the drain stack spread heat from the gate stack into the source stack and the drain stack.
8. The thermal-aware FinFET recited in claim 7, wherein the source stack and the drain stack are formed from a material that causes the heat to further flow downward into the substrate and upward through the source stack and the drain stack.
9. A method for forming a finned field-effect transistor (FinFET), comprising: forming a source stack and a drain stack on a substrate; and forming a gate stack on the substrate in a channel region disposed between the source stack and the drain stack, wherein forming the gate stack comprises: forming multiple channel structures that intersect the source stack and the drain stack, wherein the multiple channel structures comprise a lower-most channel structure formed on the substrate; and forming thermal-efficient layers around the multiple channel structures from a high-k dielectric material and a material having a high thermal conductivity.
10. The method recited in claim 9, wherein the multiple channel structures are formed from a material having a lattice matched to the material in the thermal-efficient layers having the high thermal conductivity.
11. The method recited in claim 10, wherein the thermal-efficient layers comprise a first layer formed on the lower-most channel structure through epitaxial growth and at least one second layer having one of the multiple channel structures formed thereon through epitaxial growth.
12. The method recited in claim 10, wherein the material in the thermal-efficient layers having the high thermal conductivity comprises one or more of aluminum nitride or beryllium oxide.
13. The method recited in claim 12, wherein the material used in the multiple channel structures with the matching lattice comprises one or more of silicon, indium gallium arsenide, silicon-germanium, or a III-V nitride.
14. The method recited in claim 9, wherein the material having the high thermal conductivity causes heat to flow downward into the substrate and upward to a metal gate formed atop the gate stack.
15. The method recited in claim 14, wherein the multiple channel structures that intersect the source stack and the drain stack spread heat from the gate stack into the source stack and the drain stack.
16. The method recited in claim 15, wherein the source stack and the drain stack are formed from a material that causes the heat to further flow downward into the substrate and upward through the source stack and the drain stack.
17. A thermal-aware finned field-effect transistor (FinFET), comprising: a substrate; a source stack and a drain stack formed on the substrate, wherein the source stack and the drain stack each comprise an aluminum nitride layer formed on the substrate and a graphene layer formed over the aluminum nitride layer; and a gate stack formed on the substrate, wherein the gate stack comprises: one or more fin-shaped structures formed from aluminum nitride in a channel region between the source stack and the drain stack; and a graphene channel formed over the fin-shaped structures.
18. The thermal-aware FinFET recited in claim 17, wherein the aluminum nitride layer and the one or more fin-shaped structures formed from aluminum nitride cause heat to flow downward into the substrate.
19. The thermal-aware FinFET recited in claim 17, wherein the graphene layer substantially surrounds the aluminum nitride layer and extends through the gate stack to form the graphene channel such that the graphene channel substantially surrounds the fin-shaped structures formed from the aluminum nitride in the channel region.
20. The thermal-aware FinFET recited in claim 19, wherein the graphene layer and the graphene channel spread heat throughout the thermal-aware FinFET.
21. The thermal-aware FinFET recited in claim 17, wherein the gate stack further comprises an insulator layer formed over the graphene channel and a metal gate formed over the insulator layer.
22. A method for forming a finned field-effect transistor (FinFET), comprising: forming a source stack and a drain stack on a substrate, wherein the source stack and the drain stack each comprise an aluminum nitride layer formed on the substrate and a graphene layer formed over the aluminum nitride layer; and forming a gate stack on the substrate, wherein forming the gate stack comprises: forming one or more fin-shaped structures from aluminum nitride in a channel region between the source stack and the drain stack; and forming a graphene channel over the fin-shaped structures.
23. The method recited in claim 22, wherein the aluminum nitride layer and the one or more fin-shaped structures formed from aluminum nitride cause heat to flow downward into the substrate.
24. The method recited in claim 22, wherein the graphene layer substantially surrounds the aluminum nitride layer and extends through the gate stack to form the graphene channel such that the graphene channel substantially surrounds the fin-shaped structures formed from the aluminum nitride in the channel region.
25. The method recited in claim 24, wherein the graphene layer and the graphene channel spread heat throughout the thermal-aware FinFET.
26. The method recited in claim 22, wherein forming the gate stack further comprises: forming an insulator layer over the graphene channel; and forming a metal gate over the insulator layer.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] A more complete appreciation of the various aspects and embodiments described herein and many attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings which are presented solely for illustration and not limitation, and in which:
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DETAILED DESCRIPTION
[0023] Various aspects and embodiments are disclosed in the following description and related drawings to show specific examples relating to exemplary aspects and embodiments. Alternate aspects and embodiments will be apparent to those skilled in the pertinent art upon reading this disclosure, and may be constructed and practiced without departing from the scope or spirit of the disclosure. Additionally, well-known elements will not be described in detail or may be omitted so as to not obscure the relevant details of the aspects and embodiments disclosed herein.
[0024] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. Likewise, the term “embodiments” does not require that all embodiments include the discussed feature, advantage or mode of operation.
[0025] The terminology used herein describes particular embodiments only and should not be construed to limit any embodiments disclosed herein. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Those skilled in the art will further understand that the terms “comprises,” “comprising,” “includes,” and/or “including,” as used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
[0026] Further, various aspects and/or embodiments may be described in terms of sequences of actions to be performed by, for example, elements of a computing device. Those skilled in the art will recognize that various actions described herein can be performed by specific circuits (e.g., an application specific integrated circuit (ASIC)), by program instructions being executed by one or more processors, or by a combination of both. Additionally, these sequence of actions described herein can be considered to be embodied entirely within any form of computer readable storage medium having stored therein a corresponding set of computer instructions that upon execution would cause an associated processor to perform the functionality described herein. Thus, the various aspects described herein may be embodied in a number of different forms, all of which have been contemplated to be within the scope of the claimed subject matter. In addition, for each of the aspects described herein, the corresponding form of any such aspects may be described herein as, for example, “logic configured to” and/or other structural components configured to perform the described action.
[0027] According to various aspects, as described in further detail herein, a thermal-aware finned field-effect transistor (FinFET) design may address self-heating problems in FinFET devices and other nanoscale devices. More particularly, in various embodiments, a FinFET layout may comprise aluminum nitride (AlN) fins that can provide a main thermal exit and a source, drain, and channel formed from materials that can spread or dissipate heat. For example, AlN has a high thermal conductivity (K=285 W/mK) compared to a silicon (Si) fin with a ten (10) nanometer width (5-20 W/mK), whereby using AlN to form the fins in the thermal-aware FinFET design may increase heat flux to a silicon substrate ˜15-60 times relative to fins formed from silicon. Furthermore, using thermal-efficient materials to form the source, drain, and channel device structures may further spread heat and decrease hot spot temperatures.
[0028] According to various aspects, referring to
[0029] Furthermore, a gate stack 120 may include a finger 124 wrapping the fins 122 disposed in the channel region. Furthermore,
[0030] For example, according to various aspects,
[0031] According to various aspects,
[0032] For example, referring to
[0033] Accordingly, referring back to
[0034] According to various aspects,
[0035] According to various aspects,
[0036] Accordingly, in various embodiments, the thermal efficient materials used in the gate stack may include AlN, BeO, and/or other suitable materials that have a sufficiently high thermal conductivity and a lattice structure that can be matched to the channel materials, whereby possible candidate channel materials may comprise silicon (Si), indium gallium arsenide (InGaAs), silicon-germanium (SiGe), and/or III-V nitrides. As a result, using high-k dielectrics and other thermal-efficient materials in the thermal-efficient layers may provide an efficient heat exit through causing heat to flow down into the substrate and to the gate metal disposed on top of the gate stack, which may be formed from tungsten (W), aluminum (Al), and/or any other suitable metal. Furthermore, at block 960, the source and drain may be patterned at least in part using materials with high thermal-conductivities, which may further assist in spreading heat from the channel structures. The materials used in the source stack and the drain stack may therefore continue to spread and remove heat, which exits down into the substrate and upward to the metal disposed at the top of the source stack and the drain stack.
[0037] According to various aspects, the thermal-aware FinFET design(s) described herein may be provided in, integrated into, or otherwise implemented in any suitable integrated circuit and/or processor-based device that has one or more integrated circuits that implement the horizontal FinFET, the multi-finger vertical FET, and/or any other suitable device based on the thermal-aware FinFET design(s) described herein. For example, in various embodiments, integrated circuits and/or processor-based devices that can include the thermal-aware FinFET design(s) may include, without limitation, a microprocessor-based integrated circuit, system, or other suitable electronic device(s). For example, processor-based electronic devices that can include or otherwise employ the thermal-aware FinFET design(s) described herein can comprise mobile phones, cellular phones, computers, portable computers, desktop computers, personal digital assistants (PDAs), monitors, computer monitors, televisions, tuners, radios, satellite radios, digital music players, portable music players, digital video players, digital video disc (DVD) players, portable digital video players, or the like.
[0038] For example, according to various aspects,
[0039] According to various aspects, other devices can also be connected to the system bus 1020. For example, as illustrated in
[0040] According to various aspects, the CPU(s) 1010 may also be configured to access the display controller(s) 1040 over the system bus 1020 to control information sent to one or more displays 1070. The display controller 1040 can include a memory controller 1042 and a memory 1044 to store data to be sent to the display(s) 1070 in response to communications with the CPU(s) 1010. As such, the display controller(s) 1040 may send information to the display(s) 1070 to be displayed via one or more video processors 1060, which may process the information to be displayed into a format suitable for the display(s) 1070. The display(s) 1070 can include any type of display, including but not limited to a cathode ray tube (CRT), a liquid crystal display (LCD), a plasma display, etc.
[0041] Those skilled in the art will appreciate that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
[0042] Further, those skilled in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted to depart from the scope of the various aspects and embodiments described herein.
[0043] The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, etc.).
[0044] The methods, sequences and/or algorithms described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM, flash memory, ROM, EPROM, EEPROM, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in an IoT device. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.
[0045] In one or more exemplary aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of a medium. The term disk and disc, which may be used interchangeably herein, includes CD, laser disc, optical disc, DVD, floppy disk, and Blu-ray discs, which usually reproduce data magnetically and/or optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.
[0046] While the foregoing disclosure shows illustrative aspects and embodiments, those skilled in the art will appreciate that various changes and modifications could be made herein without departing from the scope of the disclosure as defined by the appended claims. Furthermore, in accordance with the various illustrative aspects and embodiments described herein, those skilled in the art will appreciate that the functions, steps and/or actions in any methods described above and/or recited in any method claims appended hereto need not be performed in any particular order. Further still, to the extent that any elements are described above or recited in the appended claims in a singular form, those skilled in the art will appreciate that singular form(s) contemplate the plural as well unless limitation to the singular form(s) is explicitly stated.