Back gating of Metal/Semiconductor junction

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In summary, when a metal is brought into contact with a semiconductor (n-type), a depletion layer is formed at the metal-semiconductor interface where band bending occurs. If a back-gate with a negative polarity is placed on the back-side of the semiconductor, it can cause an accumulation of holes under the gate, known as inversion. This can also affect the depletion layer width at the metal-semiconductor junction through recombination with the ionized donors.
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fk08
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When a metal is brought into contact with a semiconductor (n-type) a depletion layer is formed at the metal-semiconductor interface on which band bending occurs. In the full-depletion model it is assumed that all donors are positively charged (withi this layer). What happens if a back-gate (with a insulating thin layer) at the back-side of the semiconductor is placed with a negative polarity?

Similar to pnp MOSE FETs I would expect that for a sufficient large voltage the chemical potential is driven into the valence band so that right under this gate an accumulation of holes is created, i.e. inversion. But what happens with the repelled electrons? Can they affect the depletion layer width at the metal-semiconductor junction through recombination with the ionized donors?
 
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Negative polarity with respect to what? You need a circuit to apply a bias. The other end of the battery would go to the other metal. So you're basically putting a positive bias on the metal of the M-S junction. This does affect that depletion width.
 

1. What is Back gating of Metal/Semiconductor junction?

Back gating of Metal/Semiconductor junction is a technique used to control the electrical properties of a semiconductor device. It involves applying a voltage to the back side of a semiconductor material, which creates an electric field that modifies the properties of the junction between the metal and the semiconductor.

2. How does Back gating affect the properties of the junction?

By applying a voltage to the back side of the semiconductor material, the electric field created can change the carrier concentration and mobility of the electrons and holes in the junction. This results in a modification of the device's electrical properties such as conductivity, resistivity, and capacitance.

3. What are the applications of Back gating in Metal/Semiconductor junctions?

Back gating is commonly used in the fabrication of field-effect transistors (FETs) to control the flow of current through the device. It is also used in other semiconductor devices such as solar cells, sensors, and LEDs to improve their performance and efficiency.

4. What are the advantages of Back gating in Metal/Semiconductor junctions?

The use of back gating allows for the modification of the electrical properties of a semiconductor device without altering its physical structure. This makes it a versatile and non-destructive technique for fine-tuning the performance of devices. It also offers better control and stability compared to other methods of modifying device properties.

5. Are there any limitations to Back gating in Metal/Semiconductor junctions?

One limitation of back gating is that it may introduce unwanted parasitic capacitance and resistance, which can affect the performance of the device. Also, the voltage applied to the back gate must be carefully controlled to avoid damaging the device. Additionally, back gating may not be suitable for all types of semiconductor materials and device structures.

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