An improved buried layer rectifier structure with P-type islands

A new BLR structure with P type islands (PI-BLR) is proposed, the principle of which is to introduce P type islands into the JFET region of the basic BLR structure. The forward voltage drop (V_F) of BLR can be further reduced without affecting the breakdown voltage of BLR. Thus, an attractive method is provided to coordinate the trade-off relationship between forward voltage drop and breakdown voltage. The simulations by MEDICI show that the improved structure exhibits an ultra-low V_F which decreases by 7% compared with the basic BLR at current density of 2*10^-6A/μm².