Scaled planar transistor devices present significant increases of the leakage current exacerbated by process variations, which limits the performance of some electronic applications. FinFET technology has been adopted starting 22 nm technology node for high-performance and power-efficient applications. This chapter introduces FinFET devices. The fabrication steps for making fins and middle-of-line MOL local interconnects are described.
Design issues unique to FinFET technology are discussed. A step-by-step procedure to create the layout of an inverter cell is presented. The main sources of process variations in FinFET technology are analyzed, and their impact on the delay performance of logic cells is discussed. The computing of the delay variance standard deviation of an inverter gate based on FinFET technology is presented.
A hand-by-hand example of computing the delay of a single logic cell is presented. Skip to main content. Advertisement Hide. Chapter First Online: 19 April This is a preview of subscription content, log in to check access.
Ho, X. Sun, C. Shin, T. IEEE Trans.
Toward Quantum FinFET
Electron Devices 60 128—33 Google Scholar. Mack, Seeing double. IEEE Spectrum 11 4546—51 Chiang, J. Amirtharaj, Z. Bailey, A. Tritchkov, J.Compared to the more usual planar technology, FinFET transistor technology offers some significant advantages in IC design.
The FinFET technology promises to provide the deliver superior levels of scalability needed to ensure that the current progress with increased levels of integration within integrated circuits can be maintained. The FinFET offers many advantages in terms of IC processing that mean that it has been adopted as a major way forwards for incorporation within IC technology.
FinFET technology has been born as a result of the relentless increase in the levels of integration. The basic tenet of Moore's law has held true for many years from the earliest years of integrated circuit technology.
Essentially it states that the number of transistors on a given area of silicon doubles every two years. Some of the landmark chips of the relatively early integrated circuit era had a low transistor count even though they were advanced for the time.
The microprocessor for example had just transistors. Todays have many orders of magnitude more.
What is a FET: Field Effect Transistor: Types, Technology, . .
To achieve the large increases in levels of integration, many parameters have changed. Fundamentally the feature sizes have reduced to enable more devices to be fabricated within a given area. However other figures such as power dissipation, and line voltage have reduced along with increased frequency performance. There are limits to the scalability of the individual devices and as process technologies continued to shrink towards 20 nm, it became impossible to achieve the proper scaling of various device parameters.
Those like the power supply voltage, which is the dominant factor in determining dynamic power were particularly affected. It was found that optimising for one variable such as performance resulted in unwanted compromises in other areas like power. It was therefore necessary to look at other more revolutionary options like a change in transistor structure from the traditional planar transistor.
One of the key issues is that as technologies use smaller feature sizes, the source and the drain of the MOS devices used encroach into the channel, making it easier for leakage current to flow between them and also making it very difficult to turn the transistor off completely.
FinFETs are 3d structures that rise above the substrate and resemble a fin. The 'fins' form the source and drain, effectively and in this way they enable more volume than a traditional planar transistor for the same area.
The gate wraps around the fin, and this gives more control of the channel as there is sufficient length for the control. Also as the channel has been extended there is very little current to leak through the body when the device is in the 'off' state. This also allows the use of lower threshold voltages and it results in better performance and lower power dissipation.
The gate orientation is at right angles to the vertical fin. And to traverse from one side of the fin to the other it wraps over the fin, enabling it to interface with three side of the fin or channel. This form of gate structure provides improved electrical control over the channel conduction and it helps reduce leakage current levels and overcomes some other short-channel effects.
The term FinFET is used somewhat generically. Sometimes it is used to describe any fin-based, multigate transistor architecture regardless of number of gates.Semiconductor and integrated circuit developments continue to proceed at an incredible pace.
This has been accomplished by making devices smaller and smaller. We place special emphasis on current issues related to manufacturing the next generation devices. This course is a must for every manager, engineer and technician working in the semiconductor industry, using semiconductor components or supplying tools to the industry. April 30, Munich, Germany This course has been rescheduled to a later date due to the Coronavirus. For more information, please contact us at info semitracks.
Add To Shopping Cart. Please fax the printable registration form for public courses to us at to complete your order. For dates and locations in South East Asia, please contact us at se-asia. If a course is canceled, refunds are limited to course registration fees.
Our instructors work hard to explain semiconductor processing without delving heavily into the complex physics and materials science that normally accompany this discipline.
Participants learn basic but powerful aspects about FinFET technology. This skill-building series is divided into four segments:. From the very first moments of the seminar until the last sentence of the training, the driving instructional factor is application.
We use instructors who are internationally recognized experts in their fields that have years of experience both current and relevant in this field.
The accompanying textbook offers hundreds of pages of additional reference material participants can use back at their daily activities.
Gambino received his B. While there, he developed contact and interconnect processes for 0. He has published over 90 technical papers and holds over patents. Refund Policy If a course is canceled, refunds are limited to course registration fees. Participants study the major developments associated with BEOL processing, including copper metallization and Low-k Dielectrics. Participants learn how semiconductor manufacturers are currently processing FinFET devices and the difficulties associated with three-dimensional structures from a processing and metrology standpoint.
FinFET Reliability. They also study the failure mechanisms and techniques used for studying the reliability of these devices.
Advanced CMOS/FinFET Fabrication
Course Objectives The seminar will provide participants with an in-depth understanding of SOI technology and the technical issues. Participants will also understand how FinFET devices are manufactured.The basic electrical layout and the mode of operation of a FinFET does not differ from a traditional field effect transistor. There is one source and one drain contact as well as a gate to control the current flow.
In contrast to planar MOSFETs the channel between source and drain is build as a three dimensional bar on top of the silicon substrate, called fin. The gate electrode is then wrapped around the channel, so that there can be formed several gate electrodes on each side which leads to reduced leakage effects and an enhanced drive current. The manufacture of a bulk silicon-based multi gate transistor with three gates tri gate is described below.
Basis for a FinFET is a lightly p-doped substrate with a hard mask on top e. The fins are formed in a highly anisotropic etch process. Since there is no stop layer on a bulk wafer as it is in SOI, the etch process has to be time based.
In a 22 nm process the width of the fins might be 10 to 15 nm, the height would ideally be twice that or more. To isolate the fins from each other a oxide deposition with a high aspect ratio filling behavior is needed. On top of the fins the gate oxide is deposited via thermal oxidation to isolate the channel from the gate elctrode.
Since the fins are still connected underneath the oxide, a high-dose angled implant at the base of the fin creates a dopant junction and completes the isolation not illstrated. The influence of the top gate can also be inhibited by the deposition of a nitride layer on top of the channel.
Since there is an oxide layer on an SOI wafer, the channels are isolated from each other anyway. In addition the etch process of the fins is simplified as the process can be stopped on the oxide easily.A look into how the silicide process has evolved over the years, trying to cope with the progress in scaling technology and why it could no longer be of service to finFET devices.
Since the release of the iPhone6 several blogs and articles have been written about the cost of fabrication, the perfor- mance of tri-gates, the type of work-function materials used by the manufacturers, the dominant supplier for Apple and speculation about the future of finFET devices.
TechInsights has performed detailed structural analyses of these three devices and has also tried to understand some of these questions. While comparing these structural reports on finFET devices, one small detail stands out is that a major pillar of semiconductor processing is missing. The silicide process is not being used. Samsung and TSMC at 20nm used the existing planar structure and employed NiSi on top of their source and drain regions. But as soon as these two device makers adopted finFET structure in 14 and 16nm nodes they abandoned the thirty year old silicide process.
It is interesting to look into how the silicide process has evolved over the years, trying to cope with the progress in scaling technology and finally also why it could not anymore be of service to finFET devices. The silicide process has been an integral part of semicon- ductor manufacturing since the early s.
This process is used as an interface between semiconductor material and metals to reduce the contact resistance between tungsten contacts and the source-drain regions or the gate electrode. This parasitic resistance should be minimized to enable higher drive currents in transistors.
Silicides have metal-like properties and are made by reacting Si to refractory or near-noble metals. A large number of metals in the periodic table can form silicides. The most common silicides in the semiconductor industry are titanium silicide, tungsten silicide, cobalt silicide, nickel silicide and nickel-platinum silicide.
Platinium was used to stabilize the NiSi phase at a specific temperature. These compositions can exist in various phases and have unique phase diagrams. In this scheme, no additional mask is needed; the silicide is grown on exposed silicon or polysilicon surfaces and not at all on neighboring dielectric surfaces. The main steps of growing the silicide are depositing a refractory metal or a near-noble metal on the exposed Si and then annealing in a non-oxidizing atmosphere at a suitable temperature to react the metal with Si.
The duration of the thermal cycle should be long enough to convert the majority of the metal to a silicide composition. Several stages of annealing may be completed to stabilize the phase. Thereafter the unreacted metal is removed by wet-etching. Chen or to the lecture notes from Professor Sarsawat from Stanford University . The die markings of this device suggest that it was made in The transistors in this device have 0.
The industry realized very quickly that TiSi2 was not easily scalable. As devices scaled down it became necessary to reduce the thermal budget which had the consequence of forming CTiSi2 instead of CTiSi2, which resulted in higher contact resistance.
Since this was counter-productive, it was time to switch to a new silicide. The raised source and drain regions were formed by etching out portions of the Si substrate at the source and drain regions and then depositing epitaxial layers of Si1-xGex, where x is between 0 and 1.The FET used in many circuits constructed from discrete electronic components in areas from RF technology to power control and electronic switching to general amplification.
However the major use for the field effect transistor, FET is within integrated circuits. In this application FET circuits consume much lower levels of power than ICs using bipolar transistor technology.
This enables the very large scale integrated circuits to operate. If bipolar technology was used the power consumption would be orders of magnitude greater and the power generated far too large to dissipate from the integrated circuit.
Apart from being used in integrated circuits, discrete versions of field effect transistors are available both as leaded electronic components and also as surface mount devices. Before the first FETs were introduced into the electronic components market, the concept had been known for a number of years. There had been many difficulties in realising this type of device and making it work.
Some of the early concepts for the field effect transistor were outlined in a paper by Lilienfield inand in another paper by Heil in The next foundations were set in place during the s at Bell Laboratories where the semiconductor research group was set up.
This group investigated a number of areas pertaining to semiconductors and semiconductor technology, one of which was a device that would modulate the current flowing in a semiconductor channel buy placing an electric field close to it. During these early experiments, the researchers were unable to make the idea work, turning their ideas to another idea and ultimately inventing another form of semiconductor electronics component: the bipolar transistor.
After this much of the semiconductor research was focussed on improving the bipolar transistor, and the idea for a field effect transistor was not fully investigated for some while.
Now FETs are very widely used, providing the main active element in many integrated circuits. Without these electronic components electronics technology would be very different to what it is now.
The concept of the field effect transistor is based around the concept that charge on a nearby object can attract charges within a semiconductor channel. It essentially operates using an electric field effect - hence the name. The FET consists of a semiconductor channel with electrodes at either end referred to as the drain and the source.
A control electrode called the gate is placed in very close proximity to the channel so that its electric charge is able to affect the channel. In this way, the gate of the FET controls the flow of carriers electrons or holes flowing from the source to drain. It does this by controlling the size and shape of the conductive channel. The semiconductor channel where the current flow occurs may be either P-type or N-type.
In addition to this, there are two further categories. Increasing the voltage on the gate can either deplete or enhance the number of charge carriers available in the channel. As it is only the electric field that controls the current flowing in the channel, the device is said to be voltage operated and it has a high input impedance, usually many megohms.
How finFETs ended the service contract of silicide process
This can be a distinct advantage over the bipolar transistor that is current operated and has a much lower input impedance. Field effect transistors are widely used in all forms of circuit from those used in circuits with discrete electronic components, to those employed in integrated circuits.
The field transistor transistors can be used in many types of circuits although the three basic configurations are common source, common drain source follower and common gate. The circuit design itself if fairly straightforward and can be undertaken quite easily. As the field effect transistor is a voltage operated device rather than a current device like the bipolar transistor, this means that some aspects of the circuit are very different: the bias arrangements in particular.
However electronic circuit design with FETs is relatively easy - it is just a bit different to that using bipolar transistors. There are many ways to define the different types of FET that are available. The different types mean that during the electronic circuit design, there is a choice of the right electronic component for the circuit.
By selecting the right device it is possible to obtain the best performance for the given circuit. FETs may be categorised in a number of ways, but some of the major types of FET can be covered in the tree diagram below.A word in response to the corona virus crisis: Your print orders will be fulfilled, even in these challenging times. This book reviews a range of quantum phenomena in novel nanoscale transistors called FinFETs, including quantized conductance of 1D transport, single electron effect, tunneling transport, etc.
The goal is to create a fundamental bridge between quantum FinFET and nanotechnology to stimulate readers' interest in developing new types of semiconductor technology.
Therefore, new types of nanoscale devices are being investigated aggressively to take advantage of the quantum effect in carrier transport. The quantum confinement effect of FinFET at room temperatures was reported following the breakthrough to subnm scale technology in silicon nanowires. With chapters written by leading scientists throughout the world, Toward Quantum FinFET provides a comprehensive introduction to the field as well as a platform for knowledge sharing and dissemination of the latest advances.
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Rent the eBook. FAQ Policy. About this book This book reviews a range of quantum phenomena in novel nanoscale transistors called FinFETs, including quantized conductance of 1D transport, single electron effect, tunneling transport, etc. Offers comprehensive coverage of novel nanoscale transistors with quantum confinement effect Provides the keys to understanding the emerging area of the quantum FinFET Written by leading experts in each research area Describes a key enabling technology for research and development of nanofabrication and nanoelectronic devices.
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