Array arrangements of vertical bipolar junction transistors

A structure comprising:

• a substrate having a top surface;
• a first trench isolation region in the substrate;
• a first base layer on the top surface of the substrate, the first base layer extending across the first trench isolation region;
• a first bipolar junction transistor including a first collector in the substrate and a first emitter on a first portion of the first base layer, the first portion of the first base layer positioned between the first collector and the first emitter;
• a second bipolar junction transistor including a second collector in the substrate and a second emitter on a second portion of the first base layer, the second portion of the first base layer positioned between the second collector and the second emitter;
• a second trench isolation region in the substrate;
• and
• a second base layer on the top surface of the substrate, the second base layer extending across the second trench isolation region.

A method comprising:

• forming a trench isolation region in a substrate;
• forming a first well in the substrate;
• forming a second well in the substrate;
• forming a base layer on a top surface of the substrate, wherein the base layer extends across the trench isolation region;
• forming a first bipolar junction transistor including a first collector in the substrate and a first emitter on a first portion of the base layer, wherein the first portion of the base layer is positioned between the first collector and the first emitter;
• and
• forming a second bipolar junction transistor including a second collector in the substrate and a second emitter on a second portion of the base layer, wherein the second portion of the base layer is positioned between the second collector and the second emitter,
• wherein the first collector is a portion of the first well, and the second collector is a portion of the second well.