Method in the fabrication of an integrated injection logic circuit

A method of manufacturing an integrated injection logic circuit, the integrated injection logic circuit including a lateral bipolar transistor of a first doping type and a vertical bipolar multicollector transistor of a second doping type opposite to said first doping type, the method comprising:

• forming in a substrate (i) a base of the lateral bipolar transistor common with an emitter of the vertical bipolar multicollector transistor, (ii) a collector of the lateral bipolar transistor common with a base of the vertical bipolar multicollector transistor, and (iii) an emitter of the lateral bipolar transistor;
• depositing a first polycrystalline layer on the substrate and forming, from the first polycrystalline layer, a polycrystalline contact region for the common collector of the lateral bipolar transistor and base of the vertical bipolar multicollector transistor, and a polycrystalline contact region for the emitter of the lateral bipolar transistor;
• depositing an isolation layer and forming, from the isolation layer, an isolation structure for electric isolation of the polycrystalline contact region for the common collector of the lateral bipolar transistor and base of the vertical bipolar multicollector transistor;
• and
• depositing a second polycrystalline layer and forming, from the second polycrystalline layer, a polycrystalline contact region for the common base of the lateral bipolar transistor and emitter of the vertical bipolar multicollector transistor, and multiple collectors of the vertical bipolar multicollector transistor.