CMOS DEVICES ARCHITECTURES AND TECHNOLOGY INNOVATIONS FOR THE NANOELECTRONICS ERA

2006 ◽  
Vol 16 (01) ◽  
pp. 193-219 ◽  
Author(s):  
S. DELEONIBUS ◽  
B. de SALVO ◽  
T. ERNST ◽  
O. FAYNOT ◽  
T. POIROUX ◽  
...  

Innovations in electronics history have been possible because of the strong association of devices and materials research. The demand for low voltage, low power and high performance are the great challenges for engineering of sub 50nm gate length CMOS devices. Functional CMOS devices in the range of 5 nm channel length have been demonstrated. The alternative architectures allowing to increase devices drivability and reduce power are reviewed through the issues to address in gate/channel and substrate, gate dielectric as well as source and drain engineering. HiK gate dielectric and metal gate are among the most strategic options to consider for power consumption and low supply voltage management. It will be very difficult to compete with CMOS logic because of the low series resistance required to obtain high performance. By introducing new materials ( Ge , diamond/graphite Carbon, HiK, …), Si based CMOS will be scaled beyond the ITRS as the future System-on-Chip Platform integrating new disruptive devices. The association of C-diamond with HiK as a combination for new functionalized Buried Insulators, for example, will bring new ways of improving short channel effects and suppress self-heating. That will allow new optimization of Ion-Ioff trade offs. The control of low power dissipation and short channel effects together with high performance will be the major challenges in the future.

2021 ◽  
Vol 23 (2) ◽  
pp. 75-82
Author(s):  
Masalsky N.V. ◽  

We discuss the issues of synthesis of low-voltage logic gates on cylindrical surrounding gate SOI CMOS nanotransistors in the supply voltage range up to 0.8 V. In this transistor architecture, it becomes possible to more effectively control the charge in its working area, primarily due to its design parameters. It is also characterized by effective suppression of short-channel effects and a low capacitance value. This leads to a decrease in the level of power dissipation in combination with a reduction in the occupied area. TCAD models of n- and p-types nanotransistors have been developed. The anomalous behavior of the dependence of the threshold voltage on the diameter of the working area is revealed, which is associated with the peculiarities of the manifestation of short-channel effects due to the capacitive interaction of the gate-channel regions and drain-source transitions at small gate lengths. They were used to select prototypes of transistors with optimal parameters for the synthesis of complex logic gates with low supply voltage. Using the mathematical core of the HSPICE program, the dynamic characteristics of the developed physical models of the inverter, the inverter chain, and the XOR2 are numerically investigated. At control voltages of 0.8 V and a frequency of 50 GHz, the inverter model predicts a maximum switching delay of 3.3 ps, a limit level of active power of 1.1 mkW, static 0.3 pW, the XOR2 predicts a maximum switching delay of 8.6 ps, a limit level of active power of 4.9 mkW, static 1.5 pW. The minimum of the product "delay * power" of the adder is at a supply voltage of 0.72 V. Its position does not depend on the set of input signals. At the same time, the maximum switching delay is 10.8 ps, the maximum active power level is 3.9 mkW. The totality of the obtained characteristics allows us to consider the analyzed transistor architecture for creating low-power electronic devices.


2011 ◽  
Vol 110-116 ◽  
pp. 5150-5154
Author(s):  
K. Senthil Kumar ◽  
Saptarsi Ghosh ◽  
Anup Sarkar ◽  
S. Bhattacharya ◽  
Subir Kumar Sarkar

With the emergence of mobile computing and communication, low power device design and implementation have got a significant role to play in VLSI circuit design. Conventional silicon (bulk CMOS) technology couldn‘t overcome the fundamental physical limitations belonging to sub-micro or nanometer region which leads to alternative device technology like Silicon-on-Insulator (SOI) technology. In a fully-depleted FDSOI structure the electrostatic coupling of channel with source/drain and substrate through the buried layer (BL) is reduced. This allows in turn to reduce the minimal channel length of transistors or to relax the requirements on Si film thickness. A generalized compact threshold voltage model for SOI-MOSFET is developed by solving 2-D Poisson‘s equation in the channel region and analytical expressions are also developed for the same. The performance of the device is evaluated after incorporating the short channel effects. It is observed that in SOI, presence of the oxide layer resists the short channel effects and reduces device anomalies such as substrate leakage by a great factor than bulk-MOS. The threshold voltage and current drive make SOI the ultimate candidate for low power application. Thus SOI-MOSFET technology could very well be the solution for further ultra scale integration of devices and improvised performance.


2013 ◽  
Vol 699 ◽  
pp. 440-444
Author(s):  
M.J. Twu ◽  
R.H. Deng ◽  
Z.H. Chen ◽  
M.C. Tsai ◽  
K.C. Lin ◽  
...  

This research analyzes internal stress in the N-MOSFET. The research has two parts. First, we explore the effect of N-MOSFET channel stress when CESL layer is not utilized. The dimensional effect of spacer upon channel stress in N-MOSFET with variant width of ONO (oxide, nitride, oxide) is compared. Second, with stress applied to CESL and the spacer stressor, long/short channel effects are analyzed. It is demonstrated that when the thickness of CESL and the height of gate increase, the channel stress under the gate dielectric layer becomes tensile, and the performance is improved in the short channel, resulting in the improved performance in the whole N-MOSFET. Therefore, better device characteristics can be expected through the approach disclosed in this paper.


2021 ◽  
Vol 7 (1) ◽  
pp. 18-29
Author(s):  
Vinod Pralhad Tayade ◽  
Swapnil Laxman Lahudkar

In recent years, demands for high speed and low power circuits have been raised. As conventional metal oxide semiconductor field effect transistors (MOSFETs) are unable to satisfy the demands due to short channel effects, the purpose of the study is to design an alternative of MOSFETs. Graphene FETs are one of the alternatives of MOSFETs due to the excellent properties of graphene material. In this work, a user-defined graphene material is defined, and a graphene channel FET is implemented using the Silvaco technology computer-aided design (TCAD) tool at 100 nm and scaled to 20 nm channel length. A silicon channel MOSFET is also implemented to compare the performance. The results show the improvement in subthreshold slope (SS) = 114 mV/dec, ION/IOFF ratio = 14379, and drain induced barrier lowering (DIBL) = 123 mV/V. It is concluded that graphene FETs are suitable candidates for low power applications.


Author(s):  
M. Sutha ◽  
Dr. R. Nirmala ◽  
Dr. E. Kamalavathi

In VLSI, design and implementation of circuits with MOS devices and binary logic are quite usual. The Main Objective is to design a low power and minimum leakage Quaternary adder. The VLSI field consists of Multi-valued logic (MVL) such as ternary and Quaternary Logic (QTL). The Failures such as Short Channel Effects (SCE) Impact-ionization and surface scattering are in normalized aspects. The Quaternary radix on MVL (multi-valued logic) monitors and reduces the area. The Quaternary (four-valued) logic converts the quaternary signals and binary signals produced by the by the existing binary circuits. The Proposed is carried out with LTSPICE tool and CMOS technology.


2019 ◽  
Vol 16 (10) ◽  
pp. 4179-4187
Author(s):  
Amanpreet Sandhu ◽  
Sheifali Gupta

The Conventional Complementary Metal oxide semiconductor (CMOS) technology has been revolutionized from the past few decades. However, the CMOS circuit faces serious constraints like short channel effects, quantum effects, doping fluctuations at the nanoscale which limits them to further scaling down at nano meter range. Among various existing nanotechnologies, Quantum dot Cellular Automata (QCA) provides new solution at nanocircuit design. The technical advancement of the paper lies in designing a high performance RAM cell with less QCA cells, less occupational area and lower power dissipation characteristics. The design occupies 12.5% lower area, 16.6% lower input to output delay, and dissipates 18.26% lesser energy than the designs in the literature. The proposed RAMcell is robust due to lesser noise variations. Also it has less fabrication cost due to absence of rotated cells.


In this paper we have presented the non-uniformly doped bulk Junctionless transistor (JLT) and investigated bulk-JLT and SOI-JLT with non-uniform doping in terms of its electrical performance parameters and short channel effects (SCEs) parameters comparatively. Effective thickness of channel depends on non-uniform doping distribution parameters and this affects the performance of bulk-JLT notably, however it is not so in case of SOI-JLT. The effect of non-uniform doping on electrical characteristics of JLTs (bulk and SOI) in terms of Subthreshold Slope (SS), ON-current, OFF-Current and ON/OFF current ratio has been investigated, and the non-uniformly doped bulk-JLT exhibits high ON/OFF ratio (109 for 20 nm Gate Length). Moreover, the non-uniformly doped bulk-JLT also shows improved short-channel effects (SCEs) parameters (such as Drain Induced Barrier Lowering, Threshold Voltage variations etc.) compared to SOI-JLT. Lastly, the effect of standard deviation, dielectric constant, substrate doping, and well biasing on the device performance are examined to further improve the performance of bulk-JLT independently.


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