AbstractThe relationship between the device property under drain‐source breakdown and device structure parameters of insulated gate bipolar transistors was simulated. Then the following facts were revealed: 1) the impurity concentration in the n−drain layer and the layer thickness determine the breakdown mode. One such mode is the avalanche‐suppressed punch‐through mode proposed by the authors, where the depletion layer in the n−drain layer reaches the p+drain substrate and breakdown is caused by the hole injection from the p+drain substrate to the n−drain layer. Another mode is the nonpunch‐through mode, where avalanche takes place in the neighborhood of the junction between the p body layer and n−drain layer, causing breakdown; 2) the breakdown energy spreads more and the hot carrier concentration near the device surface is lower in the avalanche‐suppressed insulated gate bipolar transistor than in the nonpunch‐through insulated gate bipolar transistor. As a result, the breakdown resistance of the former transistor is higher than that of the latter transistor; and 3) it was found that the breakdown voltage is more stable against the changes in the drain current and temperature in the former transistor than in the latter transistor. It was found also that the former transistor has a higher surge energy endurance than th