24.5 MOSFETs
721
6
5
4
3
2
0
Si
E V
vacuum
Ti
t
P
g
A
d
P
E g
1
E C
m
Fig. 24.27 Silicon band edges in relation to different metals and their work functions
Fig. 24.28 ENIAC, the first electronic computer (J.P. Eckert, J.W. Mauchly, 1944/5). The images show only a small
part of the 18 000 vacuum tubes
24.5.5 Large-Scale Integration
Historic Development
Compared to the first computers on the basis of vacuum tubes (triodes), e.g. ENIAC (Fig. 24.28), today’s
devices are extremely miniaturized and need many orders of magnitude less power per operation.
ENIAC needed 174 kW of power. A comparable computing power was reached in 1971 with the few
cm
2 large Intel 4004 microprocessor (Fig. 24.29b) consuming only several Watts with 2300 transistors.
In 2004 about 42 million transistors were integrated in the Pentium 4 microprocessor (Fig. 24.30). Also,
memory chips started to become highly integrated (Fig. 24.29a).
The development of electronic circuit integration is empirically described by Moore’s ‘law’ [2067]
that has been valid since the 1970s. According to this law, the number of transistors doubles every
20 months (Fig. 24.31a). At the same time, the performance has been improved by an increase of the
clock speed (Fig. 24.31b).
9
9 After year 2003 data for maximum clock rate are not for highest integration density processors.
721
6
5
4
3
2
0
Si
E V
vacuum
Ti
t
P
g
A
d
P
E g
1
E C
m
Fig. 24.27 Silicon band edges in relation to different metals and their work functions
Fig. 24.28 ENIAC, the first electronic computer (J.P. Eckert, J.W. Mauchly, 1944/5). The images show only a small
part of the 18 000 vacuum tubes
24.5.5 Large-Scale Integration
Historic Development
Compared to the first computers on the basis of vacuum tubes (triodes), e.g. ENIAC (Fig. 24.28), today’s
devices are extremely miniaturized and need many orders of magnitude less power per operation.
ENIAC needed 174 kW of power. A comparable computing power was reached in 1971 with the few
cm
2 large Intel 4004 microprocessor (Fig. 24.29b) consuming only several Watts with 2300 transistors.
In 2004 about 42 million transistors were integrated in the Pentium 4 microprocessor (Fig. 24.30). Also,
memory chips started to become highly integrated (Fig. 24.29a).
The development of electronic circuit integration is empirically described by Moore’s ‘law’ [2067]
that has been valid since the 1970s. According to this law, the number of transistors doubles every
20 months (Fig. 24.31a). At the same time, the performance has been improved by an increase of the
clock speed (Fig. 24.31b).
9
9 After year 2003 data for maximum clock rate are not for highest integration density processors.