*Quiz*

1. Using Equation 7 in the Mathematical Analysis page, you can
find the space charge per unit area, Qs, induced in the silicon substrate.
(It will be an amount equal, but opposite in sign, to the charge
induced in the metal gate. ) Find a relationship for the charge *Q _{s}*
to the electric field

2. The total charge per unit area induced in the silicon can be expressed as

.

Using this equation, plot the characteristic curve *ln* |Qs(C/cm^{2}
) | *vs* Ys (V) for p-type
Si at 300 K ( *Na* =4x10^{15} cm^{-3} , *n _{i}*=
1.0x10

**Reference**

1. S.M. Sze, ' Physics of Semiconductor Devices' 2nd Ed. , John Wiley
& Sons , 1981, p369.

2. C.G.B. Garrett and W.H. Brattain, 'Physical Theory of Semiconductor
Surfaces', Phys. Rev., Vol 99 (376), 1955.