Page 100 - Microsensors, MEMS and Smart Devices - Gardner Varadhan and Awadelkarim
P. 100
MONOLITHIC PROCESSING 81
Top view Side view
S \I\
1 i 1
I
I I
m 1 \ u
(a)
1
r~h r -
F3 1 1 p^i
1
yd 1 fit 1
1 42
(b)
n epi
+
n Buried layer
(c)
n epi
(d)
l l
---' LJ ---'
n epi
(e)
Figure 4.16 Various kinds of resistors available from a bipolar process: (a) base resistor; (b) pin-
ched base resistor; (c) emitter resistor; (d) epi-resistor; and (e) pinched epi-resistor
currents or a constant capacitance. In general, these components tend to have inferior elec-
trical properties compared with discrete devices that are fabricated by employing other
technologies; therefore, extra care is required to design circuits using these components.
It is common to use discrete components as external reference capacitors and resistors
together with an 1C to achieve the necessary performance.
