Unformatted text preview: W vs. N d for the junctions described in (a). (d) Given that N a = 10 15 (and repeat for 10 18 /cm 3 ) and N d = 10 19 /cm 3 , determine the reverse bias needed to yield a maximum electric field E o in the junction which exceeds 5x10 5 V/cm. 3. A p +-n silicon diode (V o = 0.926 volts) has a donor doping of 10 17 /cm 3 and an n-region width = 1 μm. Assume that the diode has a uniform cross sectional area of 0.001 cm 2 . Refer to Fig. 5-22 for the following questions. (a) Does it break down by avalanche or punchthrough? Determine the depletion capacitance when the breakdown happens. (b) If the doping is only 1x10 16 /cm 3 , what is the minimum n-region width for punchthrough not to take place?...
View Full Document
- Spring '11
- P-n junction, maximum electric field, electric field Eo