SaM - MOSFET

• Sources:
  • Youtube (simplest)
  • Youtube (more detailed)

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Graph

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Memory Card

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Meaning of MOSFET

MOSFET: Metal Oxide Semiconductor Field Effect Transistor.

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Types of MOSFETs

MOSFET “type” or “mode”	n-type	p-type
Enhanced mode
Depletion mode

• “n-type”: the body is of n-type lightly doped silicon, while ==source (S) and drain (D) are of n-type heavely doped silicon==.
• “p-type”: the body is of p-type lightly doped silicon, while ==source (S) and drain (D) are of p-type heavely doped silicon==.
• “Enhanced type”: ==the “channel” (or “channel region”) forms when $V_{GS}$ is great enough==, and allows the passage of current from source (S) to drain (D).
• “Depletion type”: the “channel” (or “channel region”) is formed when the MOSFET is created, so it’s a doped $n$-type region, ==when $V_{GS}$ is low enough, the channel is closed== and no current will flow from source (S) to drain (D).

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Terminology (for N-MOSFET)

• S: Source (heavely doped $n^{+}$ region).
• D: Drain (heavely doped $n^{+}$ region).
• G: Gate (metal).
• Body or Substrate (lighlty doped $p$ region).
• Oxide: acts as an insulator between the body and the gate (G) terminal.
• ==The MOSFET is symmetrical==: source (S) and drain (D) can be interchanged, the defintion of source (S) is the terminal connected internally with the substrate:
  
• $V_{DS}$: voltage between drain (D) and source (S):- $V_{GS}$: voltage between gate (G) and source (S):
• Linear Region:
  
• Saturation Region:
  
• Drain Characteristics & Transfer Characteristics:

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Enhanced type N-MOSFET

Construction:

Structure:

Workings: