Schottky Diode Working and Its Applications

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Schottky Diode Working and Applications
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Schottky Diode Working and Applications
Introduction

• Schottky diode is one type of electronic
  component, which is also known as a barrier
  diode. It is widely used in different
  applications like a mixer, in radio frequency
  applications, and as a rectifier in power
  applications. Its a low voltage diode. In This
  presentation, we discusses about what is a
  Schottky diode, construction, applications,
  characteristics and advantages.

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Schottky Diode Working and Applications
What is a Schottky Diode?

• Thus creating a Schottky barrier.
• The N-type semiconductor acts as a cathode and
  the metal side acts as the anode of the diode.

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Schottky Diode Working and Applications
What is a Schottky Diode?

• A Schottky diode is also known as a hot carrier
  diode.
• Its a low voltage diode.
• Schottky diode the voltage drop normally ranges
  between 0.15 and 0.45volts.
• This lower voltage drop provides higher switching
  speed and better system efficiency.
• In Schottky diode, a semiconductormetal junction
  is formed between a semiconductor and a metal.

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Schottky Diode Working and Applications
Schottky Diode Construction

• It is a unilateral junction.
• A metal semiconductor junction is formed at one
  end and another metal semiconductor contact is
  formed at the other end.
• It is an ideal Ohmic bidirectional contact with
  no potential existing between the metal and the
  semiconductor.
• Schottky diode is a function of temperature
  dropping.
• It decreases and increasing temperature doping
  concentration in N type semiconductor.

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Schottky Diode Working and Applications
Schottky Diode Construction

• Metals of the Schottky barrier diode like
  molybdenum, platinum, chromium, tungsten
  Aluminium, gold, etc., are used and the
  semiconductor used is N type.

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Schottky Diode Working and Applications
Schottky Barrier Diode

• A Schottky barrier diode is also known as
  Schottky or hot carrier diode.
• A Schottky barrier diode is a metal
  semiconductor.
• A junction is formed by bringing metal contact
  with a moderately doped N type semiconductor
  material.
• The Schottky barrier diode is a unidirectional
  device conducting current flows only in one
  direction.

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Schottky Diode Working and Applications
Schottky Barrier Diode
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Schottky Diode Working and Applications
V-I Characteristics Of Schottky Barrier Diode

• The V-I characteristics of a Schottky barrier
  diode are below

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Schottky Diode Working and Applications
V-I Characteristics Of Schottky Barrier Diode

• The forward voltage drop of the Schottky barrier
  diode is very low compared to a normal PN
  junction diode.
• The forward voltage drop ranges from 0.3 volts to
  0.5 volts.
• The forward voltage drop of Schottky barrier is
  made up of silicon.
• The forward voltage drop increases at the same
  time increasing the doping concentration of N
  type semiconductor.
• The V-I characteristics of a Schottky barrier
  diode are very steeper compared to the V-I
  characteristics of normal PN junction diode due
  to the high concentration of current carriers.

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Schottky Diode Working and Applications
Current Components in Schottky Diode

• The Schottky barrier diode current condition is
  through majority carriers.
• Which are electrons in an N type semiconductor.
• The formula in the Schottky barrier diode is
• IT IDiffusion ITunneling IThermionic emission

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Schottky Diode Working and Applications
Current Components in Schottky Diode

• IDiffusion is diffusion current due to
  concentration gradient and diffusion current
  density.
• JnDnqdn/dx for electrons.
• Where Dn is the diffusion constant of electrons.
• q is electronic charge  1.61019coulombs
• dn/dx is a concentration gradient for electrons.

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Schottky Diode Working and Applications
Current Components in Schottky Diode

• ITunneling is the tunneling current due to
  quantum mechanical tunneling through the barrier.
  
• The probability of tunneling increases with the
  decrease in the barrier or built in potential
   and decrease in depletion layer width.
• This current is directly proportional to the
  probability of tunneling.

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Schottky Diode Working and Applications
Current Components in Schottky Diode

• IThermionic Emission is a current due to
  thermionic emission current.
• Due to thermal agitation, some carriers have
  equal energy to or larger than the conduction
  band energy to the metal-semiconductor interface,
  and to the current flow.
• This is known as thermionic emission current.
• Since the current flowing direction through the
  Schottky barrier diode is through majority charge
  carriers.

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Schottky Diode Working and Applications
Current Components in Schottky Diode

• It is suitable for high-speed switching
  applications
• because the forward voltage is very low and the
  reverse recovery time is very short.

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Schottky Diode Working and Applications
Applications Of Schottky Diode

• Schottky diodes are used for the voltage clamping
  applications.
• Used to prevention of transistor saturation due
  to the high current density in the Schottky
  diode.
• Its also be a low forward voltage drop in
  Schottky diode.
• It t is wasted in less heat, making them an
  efficient choice for applications that are
  sensitive and very efficiency.
• Schottky diodes are also used as rectifiers in
  power supplies.

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Schottky Diode Working and Applications
Advantages Of Schottky Diode

• Schottky diodes are used in many applications
  compare to other types of diodes that do not
  perform well.

• Low turn on voltage The turn on voltage for the
  diode is between 0.2 and 0.3 volts. For a silicon
  diode it is against 0.6 to 0.7 volts from a
  standard silicon diode.
• Fast recovery time A fast recovery time means a
  small amount of stored charge that can be used
  for high speed switching applications.
• Low junction capacitance It occupies a very
  small area, after the result obtained from wire
  point contact of the silicon. Since the
  capacitance levels are very small.

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Schottky Diode Working and Applications
Features Of Schottky Diode

• The features of Schottky diode mainly include the
  following
• Higher efficiency.
• Low forward voltage drop.
• Low capacitance.
• Low profile surface-mount package, ultra-small.
• Integrated guard ring for stress protection.

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Schottky Diode Working and Applications
Conclusion

• This is all about Schottky Diode Working and its
  working principle and applications. We have seen
  its construction, Schottky barrier diode , V-I
  Characteristics Of Schottky barrier diode.

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