Semiconductor Physics and Devices: Basic Principles, 4th edition Chapter 12

By D. A. Neamen Exercise Solutions

Chapter 12

Exercise Solutions

Ex 12.1

Ex 12.5

From Example 12.5, m.

_______________________________________ m
_______________________________________
Ex 12.3
Ex 12.6

_______________________________________

Ex 12.4

or

V
_______________________________________
cm
_______________________________________ Ex 12.7
Semiconductor Physics and Devices: Basic Principles, 4th edition Chapter 12
By D. A. Neamen Exercise Solutions
______________________________________________________________________________________

(a)

V
For V,

cm m
For V,

cm m
Neglecting the B-E space charge width, we
find the neutral base width to be:
Then
V,
(b)

m
V,
m
_______________________________________

Ex 12.9
Neglecting bandgap narrowing,

cm
_______________________________________
From Figure 12.26, eV for
Ex 12.8 cm ,
The space charge width extending into the
base region is

cm
_______________________________________

Ex 12.10

(a)

Now
Semiconductor Physics and Devices: Basic Principles, 4th edition Chapter 12
By D. A. Neamen Exercise Solutions
______________________________________________________________________________________
V
(b) From Figure 7.15, V
_______________________________________
s ps
Ex 12.11
(a) From Figure 7.15, V s ps
Now
(b) V

_______________________________________ ps
Then
Ex 12.12
We find
Hz MHz
Also

Hz MHz
_______________________________________
V
_______________________________________

Ex 12.13

We have

Or Test Your Understanding Solutions

TYU 12.1
F pF
_______________________________________
cm
Ex 12.14
(a)

s ps
cm
(b) Using Equation (12.15a), we find

s ps At ,

Then
Semiconductor Physics and Devices: Basic Principles, 4th edition Chapter 12
By D. A. Neamen Exercise Solutions
______________________________________________________________________________________
TYU 12.3

So

Then

or or
cm

(c) For an ideal linear function

so
cm

Ratio
_______________________________________ _______________________________________

TYU 12.2 TYU 12.4

cm
cm
(a) Now

cm

or
(b) We have

and which yields

Then, using Equation (12.21a),

or cm
_______________________________________

cm TYU 12.5
_______________________________________
Semiconductor Physics and Devices: Basic Principles, 4th edition Chapter 12
By D. A. Neamen Exercise Solutions
______________________________________________________________________________________

or
Then (c)

Now

_______________________________________
_______________________________________
TYU 12.6
TYU 12.8

or

Then
Now
mA
Now
and
mA
_______________________________________
Then
TYU 12.7 mA
(a) or
A
We find _______________________________________

TYU 12.9

( -cm)
Then (a)

For m,
For m,
So
(b)
V (b)
or mV So that
Semiconductor Physics and Devices: Basic Principles, 4th edition Chapter 12
By D. A. Neamen Exercise Solutions
______________________________________________________________________________________

Then

_______________________________________

TYU 12.10

cm
_______________________________________