Structure and method for transient voltage suppression devices with a two-region base

A transient voltage suppression (TVS) assembly for protecting electrical equipment from transient electrical energy configured to divert electrical energy from the electrical equipment, said TVS assembly comprising:

• a plurality of TVS devices coupled together in at least electrical parallel, said plurality of TVS devices each comprising:
• a first layer formed of a wide band-gap semiconductor material of a first conductivity type;
• a second layer formed of the wide band-gap semiconductor material of a second conductivity type, the second layer comprising a first thickness and a first concentration of dopant;
• a third layer of wide band-gap semiconductor material formed of the second conductivity type material over at least a portion of the second layer, the third layer comprising a second thickness and a second concentration of dopant, the second thickness being larger than the first thickness, the second concentration of dopant being less than the first concentration of dopant;
• and
• a fourth layer of wide band-gap semiconductor material formed of the first conductivity type material over at least a portion of the third layer, wherein a concentration of dopant in the second layer and the third layer is determined using:
• Nthirdlayer*tthirdlayer≦10*Nsecondlayer*tsecondlayer, where
• Nthirdlayer represents a concentration of dopant in the third layer, wherein a concentration of dopant in the third layer is, 1×1015cm−3 <Nthirdlayer≦2×1017cm3 ,
• tthirdlayer represents a thickness of the third layer,
• Nsecondlayer represents a concentration of dopant in the second layer, and
• tsecondlayer represents a thickness of the second layer, wherein a thickness of the second layer is, tsecondlayer>2 um.