Mse 630 Fall 2010 Homework #1

Yüklə 3.87 Kb.
ölçüsü3.87 Kb.
MSE 630 Fall 2010 Homework #1

  1. Assuming dopant atoms are uniformly distributed in a silicon crystal, how far apart are these atoms when the doping concentration is (a) 1013 cm-1, (b) 1018 cm-1, and (c) 5 x 1020 cm-1?

  1. Consider a piece of pure silicon 100 um long with a cross sectional area of 1 um2. How much current would flow through this “resistor” at room temperature in response to an applied voltage of 1 volt?

  1. Show that the minimum conductivity of a semiconductor sample occurs when

b. What is the expression for the minimum conductivity?

c. Is this value greatly different than the value calculated for intrinsic silicon at room temperature?

  1. When a Au atopm sits on a liattice site in a silicon crystal, it can act as either a donor or an acceptor. ED and EA levels both exist for the Au and both are close to the middle of the Si bandgap. If a small concentration of Au is placed in an N-type silicon crystal, will the Au behave as a donor or an acceptor? Explain.

  1. A silicon diode has doping concentrations on the N and P sides of ND = 1 x 1019 cm-3 and NA = 1 x 1015 cm-3. Calculate the process temperature at which each of the two sides of the diode becomes intrinsic. (Intrinsic is defined as ni = ND or NA)

Due 9/16/08

Verilənlər bazası müəlliflik hüququ ilə müdafiə olunur © 2016
rəhbərliyinə müraciət

    Ana səhifə