Semiconductor Devices and Physics (Ch. 1)

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Semiconductor Devices and Physics (Ch. 1)

• Why semiconductor?
• Foundation of the electronic industry
• Including applied physics, electrical
  engineering, electronics engineering, chemical
  engineering and materials science

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Figure 1.1. Gross world product (GWP) and sales
volumes of the electronics, automobile,
semiconductor, and steel industries from 1980 to
2000 and projected to 2010.1,2
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• 4 Topics in Ch. 1
• Four building blocks of semiconductor devices
• Semiconductor technologies
• Important semiconductor devices and applications
• Technology trends
• High density
• High speed
• Low-power consumption
• Nonvolatility

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Device Building Blocks
Figure 1.2. Basic device building blocks. (a)
Metal-semiconductor interface (b) p-n junction
(c) heterojunction interface and (d)
metal-oxide-semiconductor structure.
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• Metal-Semiconductor
• Rectifying contact only one direction
• Ohmic contact Either direction with negligibly
  small voltage drop
• MESFET, microwave dvice
• P-N Junction
• Interface between p-type (positive) and n-tpe
  (negative) semiconductors.
• PiN diode, BJT (p-n-p or n-p-n), thyristor
  (p-n-p-n)

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• Heterojunction
• Interface between two dissimilar semiconductors.
• Gallium arsenide (GaAs), high-speed and photonic
  devices
• Metal-Oxide-Semiconductor (MOS)
• Combination of a metal-oxide interface and an
  oxide-semiconductor interface.
• MOSFET

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Semiconductor Technologies
Year Technology
1918 Czochralski crystal growth
1952 III-V compounds
1952 Diffusion
1957 Lithographic photoresistor
1957 Oxide masking
1957 Epitaxial CVD growth
1958 Ion implantation
1969 Polysilicon self-aligned gate
1971 Dry etching
1982 Trench isolation
1989 Chemical mechanical polishing
1993 Copper interconnect
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Preparation of Silicon Wafers
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Major Fabrication Steps
Used with permission from Advanced Micro Devices
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Major Semiconductor Devices
Year Device
1874 Metal-semiconductor contact
1907 Light emitting diode
1947 Bipolar transistor (BJT)
1949 P-n junction
1952 Thyristor
1954 Solar cell
1960 MOSFET
1962 Laser
1966 MESFET
1967 Nonvolatile memory
1970 Charge-coupled diode (CCD)
2001 20nm MOSFET
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The First Transistor from Bell Labs
Photo courtesy of Lucent Technologies Bell Labs
Innovations
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Figure 1.5. (a) A schematic diagram of the first
nonvolatile semiconductor memory (NVSM) with a
floating gate.21 (b) A limiting case of the
floating-gate NVSMthe single-electron memory
cell.22
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Technology Trends
The cost per bit of memory chips have halved
every 3 years for successive generations of DRAMs.
Figure 1.8. Exponential increase of dynamic
random access memory density (DRAMs) versus year
based on the Semiconductor Industry Association
(SIA) roadmap.49
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Moores Law In 1964, Gordon Moore, a founder of
Intel, predicted that the number of transistors
on a chip would double roughly every year. It was
later modified in 1975 to predict doubling every
18 months. This prediction is known as Moores
law.
Figure 1.9. Exponential increase of
microprocessor computational power versus year.
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Reduction in Chip Power Consumption per IC
Redrawn from Semiconductor Industry Association,
National Technology Roadmap, 1997
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From 1970, DRAM amd CPU were the drivers because
of the rapid growth of PC and electronic
systems. Since 1990, nonvolatile memory has been
the technology driver because of the rapid growth
of portable electronic systems.
Figure 1.10. Growth curves for different
technology drivers.50