EECS 105 Spring 2002 Lecture 7 R T Howe Lecture 7 Last time Underdamped 2nd order transfer functions Today Bode plots for general transfer functions Start semiconductor properties of Si Dept of EECS University of California at Berkeley EECS 105 Spring 2002 Lecture 7 R T Howe Electronic Properties of Silicon Silicon is in Group IV Electronic structure 1s22s22p63 sp 4 Diamond lattice with 0 235 nm bond length Very poor conductor at room temperature why Dept of EECS University of California at Berkeley EECS 105 Spring 2002 Lecture 7 R T Howe Bond Model for Silicon Dept of EECS University of California at Berkeley EECS 105 Spring 2002 Lecture 7 R T Howe Thermal Equilibrium Pure Si Balance between generation and recombination determines no po Strong function of temperature T 300 K Dept of EECS University of California at Berkeley EECS 105 Spring 2002 Lecture 7 R T Howe Doping with Group V Elements P As extra bonding electron lost to crystal at room temperature Dept of EECS University of California at Berkeley EECS 105 Spring 2002 Lecture 7 R T Howe Doping with Group III Elements Boron 3 bonding electrons one bond is unsaturated Dept of EECS University of California at Berkeley EECS 105 Spring 2002 Lecture 7 R T Howe Mass Action Law Balance between generation and recombination po no ni 2 N type case P type case Dept of EECS University of California at Berkeley EECS 105 Spring 2002 Lecture 7 R T Howe Compensation Dope with both donors and acceptors Dept of EECS University of California at Berkeley EECS 105 Spring 2002 Lecture 7 R T Howe Compensation cont More donors than acceptors Nd Na no Hole concentration po Dept of EECS University of California at Berkeley
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