Contents
- 1 What is the flat-band voltage of a MOS capacitor?
- 2 Why is it hard to bend the bands in an MOS capacitor by more than about 2φf?
- 3 What forms the MOS capacitor?
- 4 How is the flat band voltage of a MOS affected?
- 5 Where is the fixed oxide charge located in MOS?
- 6 What is the workfunction voltage of silicon dioxide?
What is the flat-band voltage of a MOS capacitor?
The applied voltage at the flat-band condition, called Vfb, the flat-band voltage, is the difference between the Fermi levels at the two terminals. (5.1. 1) ψg and ψs are the gate work function and the semiconductor work function, respectively, in volts. The work function is the difference between E0 and EF.
Why is it hard to bend the bands in an MOS capacitor by more than about 2φf?
3) Why is it hard to bend the bands in an MOS capacitor by more than about 2φF ? accommodated by an increased voltage drop in the oxide, not in the semiconductor. 4) The “exact” solution for the MOS capacitor discussed in class is not really exact.
Why Mosfet is called MOS capacitor?
The acronym MOS stands for Metal oxide semiconductor. An MOS capacitor is made of a semiconductor body or substrate, an insulator and a metal electrode called a gate. The flat band voltage is an important term related to the MOS capacitor. …
What forms the MOS capacitor?
The acronym MOS stands for Metal oxide semiconductor. An MOS capacitor is made of a semiconductor body or substrate, an insulator and a metal electrode called a gate. Practically the metal is a heavily doped n+ poly-silicon layer which behaves as a metal layer.
How is the flat band voltage of a MOS affected?
The flat band voltage of real MOS structures is further affected by the presence of charge in the oxide or at the oxide-semiconductor interface. The flat band voltage still corresponds to the voltage which when applied to the gate electrode yields a flat energy band in the semiconductor.
How is the flat band of a voltage calculated?
The actual calculation of the flat band voltage is further complicated by the fact that charge can move within the oxide, while the charge at the oxide-semiconductor interface due to surface states also depends on the position of the fermi energy.
Where is the fixed oxide charge located in MOS?
|the fixed-oxide charge is located within approximately 3 nm of the SiO 2-Si interface .this charge is fixed and cannot be charged or discharged over a wide variation of surface potential. Generally, Q fis positive and depends on oxidation and annealing conditions and on silicon orientation
What is the workfunction voltage of silicon dioxide?
The workfunction is the voltage required to extract an electron from the fermi energy to the vacuum level. This voltage is between 4 and 5 Volt for most metals. It should be noted that the actual value of the workfunction of a metal deposited onto silicon dioxide is not exactly the same as that of the metal in vacuum.