AN2386 datasheet(9/30 Pages) STMICROELECTRONICS

9 / 30 page

AN2386

MOS structure

9/30

where b1 is equal to 4.76 x 10-23J/K.

Eg0 is equal to 1.21eV and it is the extrapolate value of the band-gap at 0°K while b1 is the

rate of energy gap shift with temperature. Now, (Equation 9) can be rewritten as:

Equation 13

Considering that for the silicon:

Equation 14

and that:

Equation 15

ni becomes:

Equation 16

In the interface layer oxide-semiconductor, the electron and hole concentrations depend on

the gate voltage and can be written as:

Equation 17

Equation 18

When

s is equal to

F the semiconductor surface becomes intrinsic. Instead, increasing

again, the layer becomes n-type. When ns equals to p0 a "strong inversion" occurs and the

minority carriers at the surface become the same of the majority carriers in the bulk. The

potential condition for the strong inversion occurs when:

Equation 19

As explained above, when VG is applied on the MOS structure, VOX (a part of VG) will

appear across the oxide and the rest on the silicon surface:

Equation 20

cNVe

1 T

–

-------------------------





cNve

-----





---------





cNVe

-----





3.88

•

---

–

[]

---------

14047 K

[]

3.88

•

---

2kT

----------





–

3.88

–

•

---

7023

-------------





–

[]

–

------------------





–

-------

•





–

------------------





–

-------

•





–

AN2386 Datasheet(PDF) 9 Page - STMicroelectronics

AN2386 Datasheet(HTML) 9 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Datasheet Download

Link URL