107年 - 107 國立中山大學_碩士班招生考試_電機系(甲組)：半導體概論#108989

2. A Si p-n junction has same doping concentration cm' in each side. The peak electric filed in the junction at breakdown is 2 x 10⁵VIcm. Calculate the reverse breakdown voltage of this junction at 300K. (20%)

3. Calculate the oxide capacitance, the flatband capacitance, and the high frequency capacitance in inversion of a silicon MOS capacitor with a substrate doping ，a 25 nm thick silicon dioxide and an aluminum gate (Φ_M = 4.1 V). (20%)

4. For heterojunctions in the GaAs-AlGaAs system, the direct bandgap difference is accommodated approximately in the conduction band and in the valence band. The bandgap of AlGaAs is 1.85

eV if Al composition is 0.3. Draw the band diagrams of two heterojunctions: (a)As on n-GaAs (b)As on n-GaAs (20%)

5. In a metal-Si Schottky barrier contact, the barrier height is 0.85 eV and the effective Richardson constant is 110 A/K²-cm² . Calculate the ratio of the injected hole current to the electron current at 300K. D_p = 12 cm²/s, τ_p = s, and (20%)