TERAHERTZ TRANSISTOR Presented by Sumit kumar Saha Elec. & Comm. Engineering Academy of Technology
What is Terahertz Transistor?
• 1 Tera = 1,000,000,000,000
• Transistor = “Transfer of Resister”
A transistor is a semiconductor device used to amplify and switch electronics device.
A Terahertz transistor can ran 1 trillion cycle per second
Basic Transistor
• Has at least 3 terminal for connection with external circuit
• With one terminal can operate the current flow through other two terminal
• Because the controlled output power can be much more than the controlling input power, the transistor provides amplification of a signal
• With controlled terminal we can also operate it as switch
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BJT or FET ?
• The parameters are:-
1. Input resistance
2. Noise
3. Thermal stability
4. Gain-bandwidth product
5. speed
Which is suitable for Terahertz application ?
▫ FET. Specially MOSFT.
Moore’s Law
• Doubling the number of transistors per integrated circuit in 18-24 months
• The capabilities of many digital electronic devices are strongly linked to Moore's law: processing speed, memory capacity, sensors and even the number and size of pixels in digital cameras
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What is the problem ??
• Power consumption starting it rise exponentially
• Driven by
oTransistor Off-state leakage
oTransistor Gate leakage
oHigh operating voltage
• Soft error rate
High Operating Voltage
• To solve this problem we have to consider another three parameters
Source and drain resistance
Source and drain capacitance
Gate delay and drive current
Gate Delay and Drive Current
• Gate delay is the time it takes for current to travel from the source to the drain (across the channel)
• Drive current is the amount of current that flows when the transistor is turned on.
• Smaller gate delay and larger drive current translates into FASTER transistors and circuits.
Fundamental Challenge For This
Decade • Continue Moore’s Law without Exponential
increase in Power Consumption
• Intel introduced two important technology
Depleted substrate transistor & Raised source-drain
High k-gate dielectric
• Our long term approach is:
TERAHERTZ TRANSISTER
Advantages of Terahertz Transistor
• Reduces leakage current by 10,000X for the same capacitance
• Increased reliability • High speed • Eliminates subsurface leakage• Minimizes soft error rates• Eliminates floating body effect• Less voltage required to turn ON transistor• No leakage path through substrate• Lowest junction capacitance• Ease of circuit design
Application of Terahertz Transistor
• Due to its very difficult fabrication process the cost is high. So, these type of transistors are not used in general purpose.
• Intel launched world first THz transistor of speed 2THz in 2001
• Also AMD, IBM made their first terahertz transistor in their lab of speed 3.3THz(AMD) and 2THz(IBM)
• Intel launched 10GHz processor in 2005 and their next processor of speed 20GHz will launched in upcoming year.
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Applications of Terahertz Transistor
Today they are used in:• Radiotelescopy and
Sub-MilimeterAstronomy Devices
• Medical Imaging Devices
• Security Devices• Manufacturing, Quality
Control, and Process Monitoring