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 Qs
to the electric field Es. ( i.e. at x= 0, Y
= Ys and E =Es ) And then, using
this relationship, how much Qs is expected if the electric field
Es (x=0) is 1.5x105 V/cm ? ( esi
= 11.9 eo )
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/cm2
) | vs Ys (V) for p-type
Si at 300 K ( Na =4x1015 cm-3 , ni=
1.0x1010 cm-3 ).
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.