21st May, 2019
National Institute of Technology Delhi
Question
Asked 4th Mar, 2012
What are the recent methods being used to decrease the propagation delay in semiconductor devices?
Propagation delay means the time difference between input and output.
Most recent answer
1. Minimize no. of transistors through the propagation path.
2. Minimize Capacitive ('C') effect through propagation path, since Cap. 'C' makes delay= R*C. This 'RC' delay slows down /degrades the signal propagated through the path.
All Answers (7)
from my limited knowledge of semiconductors, I would try to limit the 'transistions' through 'layers' as much as possible. And work with maybe a Chemist to determine if the materials used can be changed to allow better electron flow. I graduated in 01, might have been advancements in fiber and optics since then.
6th Mar, 2012
One of the best ways to reduce the propagation delay in to reduce the capacitive effects at the output.
Deleted profile
Well, there exist two directions to make semiconductor devices work faster
1- Improve the existing devices
2- Introduce new devices
Improving the existing devices:
If you're concerned with the mainstream of CMOS technology, the delay iseither intrinisic (channel length and interelectrode capacitances) or extrinsic from the connection lines (RC delay). Intrinsic delays may be improved by proper design of transistors (reduce channel length and reduce interelecode capacitance by proper engineering of device geometry and doping profile). The multigate MOSFET is one of these innovations. Other nano MOSFET and even ballistic transistors are invistigated. The so-called Si wire nanotransistors (SiWNT) are also investigated.
Extrinsic delays may be reduced by employing new materials for metallization (e.g. Copper-Damascene technology) and even trying to integrate optical communication lines (optical transceivers on the same chip). Actually this is hindered by the fact that the standard CMOS Si technology is not ready right-now for implementing optical devices. There exist a branch of research for Si Laser and optical devices.
If you're concerned with compund semiconductors and quantum devices, there exist an extensive research to extend their operation for higher speeds (up to TeraHertz range) at room temperature
Introducing New Devices
There exist an extensive research to hybridized Si and other semiconductor devices with carbon nanotubes. Emplying a carbon nanotube in Si Field Effect Transistors has been proven succefully .
More details and ideas will be introduced later
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