Strained-layer homojunction GaAs bipolar transistor with enhanced current gain

It is shown that the growth of strained layers can improve the current gain of a bipolar transistor by a factor of 2.5 owing to the enhanced diffusion length of the minority carriers in the base. This is demonstrated in comparison to conventionally fabricated devices. The strained-layer multistructure has been grown by LPE, adding In to the growth melt. In addition, the improvement of the diffusion lengths will be shown by measuring the hole diffusion length of longbase pn diodes. Besides this improvement in diffusion lengths the standard deviation of the measured data decreases, indicating a homogeneous layer quality.