EE130 Project Spring 2007 (Word format)
 Assignment (due 4/27/07) 4/14/07 Update (provides helpful information) -- updated 4/22/07 For the calculation of cutoff frequency fT, you should use the value of emitter-junction depletion capacitance (CdBE) that corresponds to the base-emitter bias VBE that yields IC = 1mA.  Use the equilibrium value of collector-junction depletion capacitance (CdBC), which corresponds to the edge of saturation (VBC = 0V). Note that your BJT design should meet the stated specifications to within 5% over the specified range of operating temperatures and with ±5% variation in either the base width or the base doping.  For example, this means that beta can be as low as 0.95x45 = 42.75.  (beta should be at least 45 at T = 300K for your nominal design, however.) Note that amount of band-gap narrowing in the emitter is dependent on the total dopant concentration (not the net dopant concentration). For the calculation of cutoff frequency fT, you should use the value of emitter-junction depletion capacitance (CdBE) that corresponds to the base-emitter bias VBE that yields IC = 1mA.  Use the equilibrium value of collector-junction depletion capacitance (CdBC), which corresponds to the edge of saturation (VBC = 0V). Excerpts from MEDICI manual: Statement descriptions: MEDICI: 4/26/07: If you are having difficulty obtaining nice-looking plots from MEDICI, see these suggestions. 4/25/07: If you encounter convergence problems with MEDICI, then move the base electrode closer to the emitter (e.g. set y.min and y.max each to be 0.2 microns, assuming that your emitter junction is located at a depth <0.2 microns). 4/25/07: Since MEDICI is a 2-D device simulator, the unit of device current is Amperes per micron (width).  Since your 3-D BJT emitter area is 10 microns by 1 micron, a 1 mA BJT current will correspond to 1E-4 Amps/micron in MEDICI. If you are having any difficulty logging in to one of the EECS instructional machines to run MEDICI, please see these updated instructions (updated version of Homework Assignment #8, Problem 4).