Mohammad Bagheri - Department of Electronic Engineering,College of Electrical,IT & Computer Sciences,Qazvin Branch,Islamic Azad University,Qazvin,Iran
Laleh Sanati - Islamic Azad University,Rasht,Iran.
Fatemeh Mirzaei D.K - Islamic Azad University,Lahijan,Iran
Saleh Pilehvar Javid - Islamic Azad University,Lahijan,Iran

This paper explores the Nano – scale transistors to used on computers with a very compact integrated electronic circuit. In order to further miniaturization of the circuit components in Nano – scale, maybe even the molecular level, researchers suggest several alternatives for transistor in ultra – compact circuit. These Nano scale electronic devices, like conventional transistors, operate as both switch and amplifier. But, unlike the modern field – effect transistors, that act based on the motion of the electron mass in the bulk material, the new device profits from the quantum mechanical phenomena occurred at the Nano scale. In this paper first, the conventional transistors are studied and discussed its limitations and the miniaturization problems and to solve this problem, suggest solid – state transistors that benefit from the quantum effects in Nano scale, and of those, the resonant tunneling transistor model will be discussed.

Nano-scale , quantum effect, RTD , RTT