Optimistic Outlook: Calculate Doping Concentration in the Base of a Silicon BJT

How can we estimate the doping concentration in the base of a silicon BJT?

Given the parameters DB=10 cm²/s, DE=40 cm²/s, WE=100 nm, WB = 50 nm, Ne=10¹8 cm³, and a = 0.97.

Answer:

The doping concentration in the base of the transistor can be calculated using the formula: n B = (DE x Ne x WE²)/(DB x WB x a).

When we substitute the given values into the formula, we get: n B = (40 x 10¹⁸ x (100 x 10⁻⁹)²) / (10 x 10⁶ x (50 x 10⁻⁹) x 0.97) = 32.99 x 10¹⁸ cm⁻³.

Therefore, the doping concentration in the base of this silicon BJT transistor is approximately 32.99 x 10¹⁸ cm⁻³.