Simulation of the Diffusion Profile for Enhancement of Negative Resistance and Efficiency of Silicon Single Drift Region IMPATT Diodes

The diffusion profile of a single drift region (SDR) p+nn+ silicon IMPATT diode is simulated using simple, generalized, and accurate computer methods for dc and small signal analysis of the diode for realizing high negative resistance and conversion efficiency at X-band (8 to 12 GHz). The results show that the optimized diffusion profile provides a junction depth of 0.83 to 0.86 μm with a surface concentration of 7.5 × 1025 to 1026 m−3. The optimized diode has a narrow avalanche zone with breakdown voltage of 89.3 V and conversion efficiency of 11%. The negative resistance and the negative conductance of the diode are also considerably enhanced due to optimization of the diffusion profile.