Question

Please make sure to answer part b.ii

Mobility and Drift

a) For some resistor applications, it is important to maintain a fixed value of resistance over a range of operating temperatures. Explain briefly how you could minimize variations (resulting from changes in temperature) in the resistivity of Si at temperatures near 300K. Assume that you are free to choose the value of resistivity.

b) A (non-compensated) p-type silicon sample is maintained at room temperature. When an electric field with a strength of 1000 V/cm is applied to the sample, the hole drift velocity is 1.75×10^5 cm/sec.

i) What is the mean free path of a hole in this sample? (Note: 1 kg cm^2 /V s/C = 10^-4 sec)

ii) Estimate the electron and hole concentrations in this sample.

Answer 1