A BV/sub CEO/ engineering in horizontal current bipolar transistor (HCBT) technology

A need for different breakdown voltages of vertical-current bipolar transistors on the same chip is accomplished by added process complexity and increased fabrication costs. In horizontal current bipolar transistor (HCBT) technology, the devices with different collector-emitter breakdown voltages (BV_CEO) can be fabricated just by changing the mask dimensions, without any addition to process flow. Extrinsic base has a main effect on BV_CEO due to charge sharing effect. Cutoff frequency and maximum frequency of oscillations of HCBT structures with different extrinsic base widths are measured together with BV_CEO. The optimum f_TBV_CEO product of more than 100 GHzV is achieved at extrinsic base width of 0.8 mum. The charge sharing effect is analyzed by 2D simulations and the reduction of the peak electric field in the intrinsic region is shown. Moreover, the increase of BV_CEO at low base currents is measured and explained by the current gain reduction due to SHR recombination in emitter-base depletion region. The breakdown occurs in different regions of HCBT structure at low and high currents