Forum › Category: Layout › How Does Thinner Gate Oxide Achieve Faster MOSFET Switching?
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AvatarDigitalWorld asked 5 months ago
A thinner gate oxide leads to faster MOSFET switching because it increases the gate capacitance, which lowers the threshold voltage. This results in quicker charge movement and formation of the inversion layer, enabling faster switching. Even though it might seem strange, a higher capacitance helps because the thinner oxide boosts the electric field, making charges move faster and speeding up the switching process.
3 Answers
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AvatarCircuitDesigner answered 5 months ago

I think a thinner gate oxide reduces the voltage needed to turn on the gate. This means the rise time is shorter, which makes the switching faster. Lower voltage also brings other benefits like lower power usage.

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AvatarVLSI Master answered 5 months ago

You are right, Threshold voltage is inversely related to oxide capacitance, which is inversely related to oxide thickness. With a shorter distance, the charge at the gate terminal repels the holes in the substrate more effectively. This means free electrons gather faster between the source and drain, forming an inversion layer and allowing the MOSFET to conduct more quickly.

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Avatarsemiconductor answered 5 months ago

We need to look beyond the simple RC time constant. In semiconductor physics, a thinner gate oxide increases the electric field, which speeds up charge movement. This results in faster switching times