6.1 Answer the following questions as concisely as possible.
(a) Figure 6.3 was constructed from to versus 1E data derived from high-purity (lightly doped) samples. How would the low-field region of the plots be modified if the vd versus t mea¬surements were performed on samples with higher doping concentrations? Explain.
(b) I t is determined that = 1360 cm2IV-sec and gin = 2040 cm2IV-sec in a Si sample at
300 K. Assuming phonon and impurity ion scattering to be dominant, compute the a-pected value of p. employing (i) Matthiessen's rule and (ii) Eq. (6.8).
(c) Assuming that NA = No = 0, compute the resistivity of (i) intrinsic Si and (ii) intrinsic GaAs at 300 K.
(d) Sketch the approximate variation of the hole diffusion coefficient (Dr) versus doping (NA ) in silicon at room temperature. Also explain how you arrived at your answer.
(e) For temperatures Tnear room temperature, sketch the expected form of a log-log DN versus Tplot appropriate for lightly doped n-type silicon. Record the reasoning leading to your sketch.
6.5 The energy band diagram characterizing a uniformly doped Si sample maintained at room temperature is pictured Fig. P6.5.
(a) Sketch the electron and hole concentrations (n and p) inside the sample as a function of position.
(b) Sketch the electron and hole diffusion current densities (n: LH' and Jp Liao inside the sample as a function of position.
(c) Sketch the electric field ('t') inside the semiconductor as a function of position.
(d) Sketch the electron and hole drift current densities (I„, knit and Jp knit) inside the sample as a function of position.