Question

XXX is 467

Design an ideal abrupt silicon PN-junction at 300 K such that the donor impurity concentration in the n-side N, = 5x1015 cm3 and the acceptor impurity concentration in the p-side N, = XXX × 1015/cm3 Assume that the diode area A-2x10-3 cm2 and 100cm work Note that the values obtained in the calculations may not be realistic as the Matric # varies greatly. The assignment is only to test your understanding, and must be handwritten Determine the following when a forward bias of 0.6 V is applied to the diode: 1. The values (in μm) of the depletion width at the p-side xpand the depletion width at the n-side x". 2. The electric field at a distance of 0.2 × x, away from the metallurgical junction in the n-side. 3. Minority carrier hole diffusion current at the n-side depletion edge (%) 4. Minority carrier electron diffusion current at the p-side depletion edge I, xp) 5. The total diode current 6. The junction capacitance Cj under forward bias 7. Roughly, sketch the carrier distribution across the junction under forward bias. Label clearly 8. For the same forward bias of 0.6 V, an application requires higher diode current than that calculated in Part 5. If you have a choice to change the dopant concentration in one side of the junction (either p-side or n-side) to achieve this higher current, state whether you will increase or decrease the dopant concentration in the chosen side? Briefly explain your answer 9. If the pn-junction diode is made of GaAs semiconductor instead of Silicon, do you expect the total diode current I to remain the same, decrease or increase for the same forward bias of 0.6 V? Explain briefly without doing any calculation.

Answer 1

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Ep冫10 Nao calculate the value ot P ni Io 10 lo で。 (1020) ヴ on 10 20 a lO lo 0 -3

lu us lalculate the value d D BH subshtuting valve, coe aet Dp0025 O, 02.54 хЧ50 0 02 59 x700 18 13m/s кг Po 166 00259

3 731 x 161 6 0257 -. 3.73 x o 0 0259 1.1 66χιδΥ 6 U-2926x10 0 0I08 find the ul of In (po X10 8 13 21 5. sol ΧΙΟ o 0259

5801 ΧΙΟ 0 0259 一49.57 ·