Question

A metal, with a work function Ф,,-41 V, is deposited on an n-type silicon semiconductor with electron affinity 4.0V and energy bandgap 1.12eV. Assuming no interface states exist at the junction and operation temperature at 300K. Effective density of states in conduction band (N 3.22 x 10 cm3. Effective density of states in valence band (N) 1.83 x 10" cm 193 A) Sketch the energy band diagram for zero bias for the case when no space charge region exists at the junction. (4 points) B) Determine the doping concentration of n-silicon so that the condition in part (a) is satisfied. (4 points) Nr C) What is the potential barrier height seen by electrons in the metal moving into the semiconductor? (4 points) D) Ohmic contact is to be fabricated by depositing a particular metal on n-type silicon. The work function of the metal is 4.5V. Considering the ideal metal-semiconductor contact, determine the allowable range of doping concentration for the ohmic contact. E) Schottky contact is to be fabricated by depositing a particular metal on p-type silicon. The work function of the metal is 4.5V. Considering the ideal metal- semiconductor contact, determine the allowable range of doping concentration for the Schottky contact. (4 points)

Answer 1

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