Abstract :
The paper seeks the approximate functional relationship between current amplification factor, ¿ base width, w, and effective lifetime, ¿ of minority carriers in the base region of a transistor. In any set of observations this functional relationship may be obscured by variations in other parameters, so that statistical techniques must be used to eliminate their influence. The numerical calculations are based on the relationships ¿ = ¿0 ¿ g(¿, w) = ¿0 ¿ h(¿, f¿d) = ¿0 ¿ f(¿)w¿ where g, h and f are functions of the effective lifetimes in the base region. The data to determine h(¿, f¿d) were obtained from the curves of best fit to the scatter diagrams of ¿ against 1/¿ with f¿c0 constant. For the typical r.f. transistor under consideration the general relationship ¿ = ¿0 ¿ 0.21/f¿d0.9¿ was obtained; this is basically in agreement with that developed by Stripp and Moore. The paper examines the statistical method involved and its application to the particular problem. The measuring techniques are discussed in the light of possible errors and their compensation, and formulae are derived for ¿ and f(¿). The probable causes of the statistical spreads observed are reviewed and the results obtained are compared with the findings of Stripp and Moore.
