Trench gate IGBT

A trench gate insulated gate bipolar transistor (IGBT) comprising:

• a substrate;
• a first-conductivity-type channel layer provided on the substrate;
• a first first-conductivity-type floating layer provided on a first side of the channel layer;
• a second first-conductivity-type floating layer provided on a second side of the channel layer opposite the first side;
• a first emitter trench disposed in the channel layer between the first first-conductivity-type floating layer and the first side of the channel layer, the first emitter trench contacting both the first floating layer and the first side of the channel layer;
• a second emitter trench disposed in the channel layer between the second first-conductivity-type floating layer and the second side of the channel layer, the second emitter trench contacting both the second floating layer and second side of the channel layer;
• a first gate trench and a second gate trench disposed in the channel layer between the first and second emitter trenches;
• a first source diffusion region and a second source diffusion region disposed in the channel layer between the first and second gate trenches, the first source diffusion region being in contact with the first gate trench and the second source diffusion region being in contact with the second gate trench;
• an insulation film on a top surface of the channel layer, the first and second floating layers, the first and second emitter trenches, the first and second gate trenches, and the first and second source diffusion regions;
• and
• an emitter electrode on a top surface of the insulation film,
• wherein the first and second floating layers are deeper than the channel layer, and
• wherein the insulation film has a plurality of via holes to provide a contact of the emitter electrode to the top surface of the channel layer, including a first via hole for contact to the channel layer between each of the two gate trenches, a second via hole for contact to the channel layer between a first gate trench and the first emitter trench, and a third via hole for contact to the channel layer between the second gate trench and the second emitter trench Contact.