ENGR 353-Jiang
Review #1: Semiconductor Physics
_____________________________________________________________________________________
Problem 1:
A piece of Si is doped with Phosphorus to 1×1018 [1/cm3]
Please calculate the followings:
(a)
(b)
(c)
(d)
(e)
What is the electron concentration?
What is the hole concentration?
What is the conductivity of this piece of Si?
Assume the thickness of the Si is 0.5 m, what is the Sheet Resistance?
If the thickness of the Si is still 0.5 m. R1 with 1m wide and 4m long, R2 with 2m wide
𝑅1
and 12 m long, What is 𝑅2?
_____________________________________________________________________________________
Problem 2:
A p-type silicon wafer resistivity is 3 ohm.cm, what is the doping concentration?
ENGR 353-Jiang
_____________________________________________________________________________________
Problem 3:
What is the sheet resistance of a 1 m thick p-type poly with doping concentration p=1×1018 1/cm3? What
𝐷
𝑘𝑇
is the diffusion constant of the electrons 𝜇 = 𝑞
D: Diffusion Constant [cm2/sec],
: Mobility [cm2/(V.sec)],
k: Boltzmann’s constant k = 1.38×10-23[J/K]
T: Temperature in Kelvin T=298.15K is the IEEE standard room temperature
Q: Charge q = 1.6×1019 [C]