Which of the following describes MOSFET construction?
The correct answer is B: The gate is separated from the channel by a thin insulating layer. What describes MOSFET construction is that the gate is separated from the channel by a thin insulating layer. MOSFETs have an insulated gate (Metal-Oxide-Semiconductor), unlike bipolar transistors. For amateur radio operators, this is a key MOSFET characteristic. Understanding this helps when using MOSFETs.
Exam Tip
MOSFET construction = gate separated from channel by thin insulating layer. Think 'M'OSFET = 'M'etal-'O'xide-'S'emiconductor = 'G'ate 'I'solated. Gate is insulated from channel by thin oxide layer. Not back-biased junction, not source-drain insulation, not metal deposition - just gate insulation.
Memory Aid
"MOSFET construction = gate separated from channel by thin insulating layer. Think 'M'OSFET = 'M'etal-'O'xide-'S'emiconductor. Gate is insulated from channel by thin oxide layer. Key MOSFET characteristic."
Real-World Application
A MOSFET has a gate electrode separated from the semiconductor channel by a thin insulating layer (oxide). This insulated gate allows voltage control without gate current, unlike bipolar transistors. The 'MOS' in MOSFET stands for Metal-Oxide-Semiconductor, referring to this insulated gate structure.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. The gate isn't formed by a back-biased junction - that's a JFET, not a MOSFET. MOSFETs have insulated gates, not junction gates.
Option C: Incorrect. The source isn't separated from the drain by an insulating layer - source and drain are both in the semiconductor. The gate is insulated, not source-drain.
Option D: Incorrect. The source isn't formed by depositing metal on silicon - source and drain are semiconductor regions. Metal deposition isn't how source is formed.
题目解析
The correct answer is B: The gate is separated from the channel by a thin insulating layer. What describes MOSFET construction is that the gate is separated from the channel by a thin insulating layer. MOSFETs have an insulated gate (Metal-Oxide-Semiconductor), unlike bipolar transistors. For amateur radio operators, this is a key MOSFET characteristic. Understanding this helps when using MOSFETs.
考试技巧
MOSFET construction = gate separated from channel by thin insulating layer. Think 'M'OSFET = 'M'etal-'O'xide-'S'emiconductor = 'G'ate 'I'solated. Gate is insulated from channel by thin oxide layer. Not back-biased junction, not source-drain insulation, not metal deposition - just gate insulation.
记忆口诀
MOSFET construction = gate separated from channel by thin insulating layer. Think 'M'OSFET = 'M'etal-'O'xide-'S'emiconductor. Gate is insulated from channel by thin oxide layer. Key MOSFET characteristic.
实际应用示例
A MOSFET has a gate electrode separated from the semiconductor channel by a thin insulating layer (oxide). This insulated gate allows voltage control without gate current, unlike bipolar transistors. The 'MOS' in MOSFET stands for Metal-Oxide-Semiconductor, referring to this insulated gate structure.
错误选项分析
Option A: Incorrect. The gate isn't formed by a back-biased junction - that's a JFET, not a MOSFET. MOSFETs have insulated gates, not junction gates. Option C: Incorrect. The source isn't separated from the drain by an insulating layer - source and drain are both in the semiconductor. The gate is insulated, not source-drain. Option D: Incorrect. The source isn't formed by depositing metal on silicon - source and drain are semiconductor regions. Metal deposition isn't how source is formed.
知识点
MOSFET, Gate insulation, Thin insulating layer, Transistor construction
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.