What are Schottky contacts?
The rectifying contact that occur between a metal and a lightly doped semiconductor. b) Ideal energy -band diagram of a metal and n-type semiconductor junction. …
What is difference between ohmic contact and Schottky contact?
Schottky Contacts make good diodes, and can even be used to make a kind of transistor, but for getting signals into and out of a semiconductor device, we generally want a contact that is Ohmic. Ohmic contacts conduct the same for both polarities. (They obey Ohm’s Law).
What’s the Schottky barrier height?
Schottky, is a potential energy barrier for electrons formed at a metal–semiconductor junction. Schottky barriers have rectifying characteristics, suitable for use as a diode. One of the primary characteristics of a Schottky barrier is the Schottky barrier height, denoted by ΦB (see figure).
What are ohmic and Schottky contacts with reference to metal semiconductor junction?
A Schottky junction is formed when the semiconductor has a lower work func- tion than the metal. When the semiconductor has a higher work function the junction formed is called the Ohmic junction.
What is the concept of Schottky barrier?
The Schottky barrier is the energy difference between the valence (or conduction) band edge of the semiconductor and the Fermi energy of the metal, while the band offset is the energy difference of valence (or conduction) bands of two materials that construct the interface.
What is a Schottky defect?
Definition of Schottky defect : a defect in a crystal lattice created by removing an ion from its normal site and placing it on the crystal surface.
What determines whether a metal semiconductor contact should become Schottky or ohmic?
Conclusion. Overall, for a metal and an n-type semiconductor, a rectifying Schottky contact is formed when ΦM>ΦS, and an Ohmic contact is formed when ΦM<ΦS. Similarly, for a metal and an p-type semiconductor, the MS contact will be rectifying Schottky when ΦM<ΦS, and Ohmic contact when ΦM>ΦS.
What is the properties of ohmic contact?
The Ohmic contact is a low resistance junction (non-rectifying) provides current conduction from metal to semiconductor and vice versa. Theoretically speaking the current should increase/ decrease linearly with the applied voltage. With an immediate response for the any small voltage.
How do I contact Schottky?
A schottky contact is typically formed using a metal with workfunction higher than the semiconductor conduction band. It depends on which semiconductor you are using. For n-type Si, you can use Ti for ohmic contact and Ni for schottky contact.
How is a Schottky barrier formed?
The Schottky barrier, shown in Figure 6-2, is formed by an electron blocking contact for which ϕm > ϕs. The condition for a contact to be blocking, seen by electrons from the metal, is ϕm > ϕs for a metal–n-type semiconductor junction, or ϕm > ϕ for a metal–intrinsic semiconductor (or metal–insulator) junction.
Why depletion region in Schottky contact is smaller than the pn junction?
1. Schottky interface(contact) is “smaller” than the p-n interface(contact) because the Schottky contact is 1/2 junction (only one majority carriers depletion region), while p-n junction is a full junction (two depletion regions formed by the respective majority carriers).
What are the schottky contact boundary conditions for the carrier temperature?
The Schottky contact boundary conditions for the carrier temperatures and and the lattice temperature are similar to the ones which apply for the Ohmic contact, i.e. (3.36) and (3.37), or respectively (3.38). Previous:3.1.6.1 Ohmic Contact Up:3.1.6 Metal-Semiconductor Contacts Next:3.1.6.3 Polysilicon Contact
What is a Schottky barrier?
A Schottky barrier refers to a metal-semiconductor contact having a large barrier height (i.e. and low doping concentration that is less than the density of states in the conduction band or valence band. The potential barrier between the metal and the semiconductor can be identified on an energy band diagram.
Are Schottky contacts thermally stable?
Schottky contacts should form a reliable (temperature stable) interface with the semiconductor. SiC, Ni, and TaSi2 have been found stable up to around 600 °C ( Saxena et al., 1999 ). However, most contacts for gas sensing are based on Pd or Pt.
What is the value of φM in Schottky Mott rule?
Φm is the metal work function, χs the semiconductor electron affinity, ω the thickness of the space-charge layer, eVs the potential barrier, and ΦB the potential barrier height. In practice, however, most metal-semiconductor interfaces do not follow the Schottky-Mott rule.