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Task 2 Determine the Oxide Relative Permittivity (εr or k)

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  The oxide relative permittivity can be calculated using the mathematical characteristics of capacitors under the accumulation region (which is the highest region of the C-V plot). Under the accumulation condition, the MOS capacitor can be seen as the series connection of the C ox and C acc .            As C acc is exponentially dependent on and therefore very large.  (C acc =dC acc /d Φ S )  So, in above equation, the term of accumulation capacitance can be ignored and the total capacitance can be seen equal to oxide capacitance. Then we can obtain the oxide capacitance by reading the max value from the C-V plot, from given data, the value is 2.92E+03pF. Then we can calculate the oxide relative permittivity through function below: With given data, we have: By substituting equations 2.2 to 2.5 into equation 2.1, we obtained  ε ox =6.8.
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Task 1 The Plot of the C-V Curve

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  The data was allocated in txt format and we put them into excel and obtained this C-V plot. Figure 1: C-V plot C-V plot (HfSiO, 70% Hf). According to the plot drawn from given data, the substrate involved in this project is p type. This conclusion is made from the characteristic of surface field effect. There are three conditions of the energy band diagram, accumulation, depletion and inversion. Under the accumulation condition of p type Si MOS system, when negative voltage is applied on the gate, positive holes in the semiconductor will be attracted to the region close to the oxide and accumulate there. When voltage applied on the gate increases to positive, the positive holes accumulated before will be repelled and leave behind some negative acceptances. Then this condition is called depletion condition. Finally, when the gate voltage is high enough, the fermi level of semiconductor in the region near to the oxide will be bend higher than the intrinsic level, and thus...
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