Fundamentals of Computer SystemsTransistors, Gates, and ICs
Stephen A. Edwards
Columbia University
Summer 2017
Semiconductor
sem·i·con·duc·tor
noun
1. A substance, such as silicon or germanium, withelectrical conductivity intermediate between that of aninsulator and a conductor
2. A semiconductor device1IA
11A
18VIIIA8A
2IIA2A
13IIIA3A
14IVA4A
15VA5A
16VIA6A
17VIIA7A
3IIIB3B
4IVB4B
5VB5B
6VIB6B
7VIIB7B
8 9VIII8
10 11IB1B
12IIB2B
Periodic Table of the Elements
LanthanideSeries
ActinideSeries
© 2013 Todd Helmenstinechemistry.about.comsciencenotes.org
1
HHydrogen1.008
3
LiLithium6.941
4
BeBeryllium9.012
11
NaSodium22.990
12
MgMagnesium24.305
19
KPotassium39.098
20
CaCalcium40.078
21
ScScandium44.956
22
TiTitanium47.88
23
VVanadium50.942
24
CrChromium51.996
25
MnManganese54.938
26
FeIron
55.933
27
CoCobalt58.933
28
NiNickel58.693
29
CuCopper63.546
30
ZnZinc65.39
31
GaGallium69.732
13
AlAluminum26.982
5
BBoron10.811
32
GeGermanium72.61
14
SiSilicon28.086
6
CCarbon12.011
33
AsArsenic74.922
15
PPhosphorus30.974
7
NNitrogen14.007
34
SeSelenium78.09
16
SSulfur32.066
8
OOxygen15.999
35
BrBromine79.904
17
ClChlorine35.453
9
FFluorine18.998
36
KrKrypton84.80
18
ArArgon39.948
10
NeNeon20.180
2
HeHelium4.003
37
RbRubidium84.468
38
SrStrontium87.62
39
YYttrium88.906
40
ZrZirconium91.224
41
NbNiobium92.906
42
MoMolybdenum
95.94
43
TcTechnetium98.907
44
RuRuthenium101.07
45
RhRhodium102.906
46
PdPalladium106.42
47
AgSilver107.868
48
CdCadmium112.411
49
InIndium114.818
50
SnTin
118.71
51
SbAntimony121.760
52
TeTellurium127.6
53
IIodine126.904
54
XeXenon131.29
55
CsCesium132.905
56
BaBarium137.327
57-71 72
HfHafnium178.49
73
TaTantalum180.948
74
WTungsten183.85
75
ReRhenium186.207
76
OsOsmium190.23
77
IrIridium192.22
78
PtPlatinum195.08
79
AuGold
196.967
80
HgMercury200.59
81
TlThallium204.383
82
PbLead207.2
83
BiBismuth208.980
84
PoPolonium[208.982]
85
AtAstatine209.987
86
RnRadon222.018
87
FrFrancium223.020
88
RaRadium226.025
89-103
57
LaLanthanum138.906
58
CeCerium140.115
59
PrPraseodymium140.908
60
NdNeodymium144.24
61
PmPromethium144.913
62
SmSamarium150.36
63
EuEuropium151.966
64
GdGadolinium157.25
65
TbTerbium158.925
66
DyDysprosium162.50
67
HoHolmium164.930
68
ErErbium167.26
69
TmThulium168.934
70
YbYtterbium173.04
71
LuLutetium174.967
89
AcActinium227.028
AlkaliMetal
AlkalineEarth
TransitionMetal
BasicMetalSemimetal Nonmetal Halogen Noble
Gas Lanthanide Actinide
90
ThThorium232.038
91
PaProtactinium231.036
92
UUranium238.029
93
NpNeptunium237.048
94
PuPlutonium244.064
95
AmAmericium243.061
96
CmCurium247.070
97
BkBerkelium247.070
98
CfCalifornium251.080
99
EsEinsteinium[254]
100
FmFermium257.095
101
MdMendelevium
258.1
102
NoNobelium259.101
103
LrLawrencium[262]
104
RfRutherfordium
[261]
105
DbDubnium[262]
106
SgSeaborgium[266]
107
BhBohrium[264]
108
HsHassium[269]
109
MtMeitnerium[268]
110
DsDarmstadtium
[269]
111
RgRoentgenium
[272]
112
CnCopernicium
[277]
113
UutUnuntriumunknown
114
FlFlerovium[289]
115
UupUnunpentiumunknown
116
LvLivermorium
[298]
117
UusUnunseptiumunknown
118
UuoUnunoctiumunknown
Sand into Silicon
Silica a.k.a. SiO2 a.k.a. Quartz
SiO2 +2 C→ Si+2 CO
Elemental, amorphous silicon
MonocrystallineSilicon Ingot
Doping Silicon Makes It a Better Conductor
Si Si Si
Si Si Si
Si Si Si
Undoped (pure)silicon crystal
Not a goodconductor
Si Si Si
Si B− Si
Si Si Si
+
p-type (doped)silicon:
boron atom stealsa nearby electron
Si Si Si
Si As+ Si
Si Si Si
−
n-type (doped)silicon:
arsenic’s extraelectron jumps loose
A PN Junction aka A Diode
p (holes) n (electrons)
Depletion region
0 V
+
+Ammeter
0
A PN Junction aka A Diode
p (holes) n (electrons)
Depletion region
2 V
+
+Ammeter
0
Forward biased: current flows
A PN Junction aka A Diode
p (holes) n (electrons)
Depletion region
−2 V
+
+Ammeter
0
Reverse biased: no current flow
An N-Channel MOS Transistor
p (holes)
n n
3 V
0 V+
+
+Ammeter
0
Drain Source
GateSiO2
Gate at 0V: Off
An N-Channel MOS Transistor
p (holes)
n n
3 V
3 V+
+
+Ammeter
0
Drain Source
GateSiO2
+++++++++−−−−−−−−
Gate positive: On
The CMOS Inverter
Y
0V
3V
A
A Y
p-FET
n-FET
An inverter is built from two MOSFETs:
An n-FET connected to ground
A p-FET connected to the power supply
The CMOS Inverter
Y
0V
3V
A
A Y
3V
1
0V
0
Off
On
When the input is near the power supplyvoltage (“1”),
the p-FET is turned off;
the n-FET is turned on, connecting theoutput to ground (“0”).
n-FETs are only good at passing 0’s
The CMOS Inverter
Y
0V
3V
A
A Y
0V
0
3V
1
On
Off
When the input is near ground (“0”),
the p-FET is turned on, connecting theoutput to the power supply (“1”);
the n-FET is turned off.
p-FETs are only good at passing 1’s
The CMOS NAND Gate
Y
A
B
AB
Y
Two-input NAND gate:
two n-FETs in series;
two p-FETs in parallel
The CMOS NAND Gate
Y
A
B
AB
Y
0
0
00
1
1
Both inputs 0:
Both p-FETs turned on
Output pulled high
The CMOS NAND Gate
Y
A
B
AB
Y
0
1
01
1
1
One input 1, the other 0:
One p-FET turned on
Output pulled high
One n-FET turned on, but does notcontrol output
The CMOS NAND Gate
Y
A
B
AB
Y
1
1
11
0
0
Both inputs 1:
Both n-FETs turned on
Output pulled low
Both p-FETs turned off
The CMOS NOR Gate
Y
A
B
AB
Y
Two-input NOR gate:
two n-FETs in parallel;
two p-FETs in series.
Not as fast as the NAND gatebecause n-FETs are faster thanp-FETs
A CMOS AND-OR-INVERT Gate
Y
C
D
A
B
ABCD
Y
Static CMOS Gate Structure
p-FETpull-up
network
n-FETpull-downnetwork
YInputs
Pull-up and Pull-downnetworks must becomplementary; exactly oneshould be connected for eachinput combination.
Series connection in oneshould be parallel in theother
CMOS Inverter Layout
Y
Vss
Vdd
A
Cross Section ThroughN-channel FET
A
Vss
Vdd
Y
Top View
Full Adder Layouts
From
http
://bo
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uih
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.com
/desig
n-o
f-vlsi-systems/
Intel 4004: The First Single-Chip Microprocessor
4001: 256-byte ROM + 4-bit IO port4002: 40-byte RAM4003: 10-bit shift register4004: 740 kHz 4-bit CPU w/ 45 instructions (2300 transistors)
Intel 4004 Masks
Intel 4004 Die Photograph