Homework #9 - due Tuesday, 24 April 2007, in class

1.  Problem 6.2, in chapter 6, Muller & Kamins, p. 321 in 3rd edition. (Hint: treat the Pt metal region as if it were a very heavily doped p-type semiconductor region, but with the Fermi level determined by its work function.

2.  Problem 6.9 in chapter 6 of Muller & Kamins, p. 322 in 3rd edition. Hint: the result of problem 6.11 is that the field is E = kT/qL for doping N = No exp(-x/L).

3.  The emitter and collector regions of a Si alloyed p-n-p transistor are heavily doped, and the impurity concentration in the base is 1E15cm-3. Calculate the base-width that will make the avalanche breakdown voltage (BVcbo) equal to the punch-through voltage. The punch through voltage is given by: Vpt = q Nd Wbo^2/(2es) , where Wbo is the metallurgical base width. Assume that avalanche breakdown occurs when the maximum field strength in the C-B depletion region becomes 5 x 10^5V/cm.
 

  Homework assignments will appear on the web at: http://www.ece.udel.edu/~kolodzey/courses/eleg646s07.html
  Note: On each homework and report submission, please give your name, the due date, assignment number and the course number. For full credit - include units/dimensions for all numerical quantities