7 pn Junction Diode: Small-signal Admittance 반도체 소자 연구실 박 종 태 e-mail : jtpark@incheon.ac.kr
small signal voltage : Va ac current : i small signal 7.1 INTRODUCTION small signal voltage : Va ac current : i small signal admittance:Y=G+jwC Y = G +jwC (7.1)
7.2 REVERSE-BIAS JUNCTION CAPACITANCE 7.2.1 General Information C-V characteristics of pn diode
(7.2) Junction or depletion layer capacitance Charge density oscillation with a.c signal (7.2)
7.2.2 C-V Relationships (7.3) and (7.4) (7.5) Vbi→Vbi-VA One sided power law profiles (7.3) and (7.4) (7.5)
Depletion region width for one sided power-law profiles (7.6) (7.7) (7.8)
For varactor , tuning ratio (7.9) (7.10)
7.2.3 Parameter Extraction/Profiling Form C-V plot Doping concentration versus position (7.11) (7.12) (7.13) Example 7.2
7.2.4 Reverse-Bias Conductance Differential dc conductance of a diode : When the reverse bias exceed a few kT/q, G0→0 When the dc recombination-generation current dominates in the given diode, (7.14) (7.15) (7.16)
7.3 FORWARD-BIAS DIFFUSION ADMITTANCE 7.3.1 General Information
The admittance due to the minority carries charge oscillation (7.17)
7.3.2 Admittance Relationships (7.29b) (7.30a) (7.30b)