Super-junction vertical double-diffused metal oxide semiconductor (VDMOS) capable of effectively preventing charge imbalance

Abstract

The invention discloses a super-junction vertical double-diffused metal oxide semiconductor (VDMOS) capable of effectively preventing charge imbalance and belongs to the field of power semiconductor devices. Deep energy level impurities are doped in the conventional super-junction VDMOS structure and a columnar region (4) of which the conductive type is opposite to that of an epitaxial region (3), wherein donor impurities such as S, Se or Te are doped in an N-channel device, and acceptor impurities such as In, Ti or Zn are doped in a P-channel device. The deep energy level donor impurities are low in ionization rate at normal temperature, the contribution of the deep energy level donor impurities on the doping concentration of the columnar region (4) can be ignored, and the static load balance of the device is not influenced. When the device is positively conducted and operates under high current, the ionization rate of the deep energy level impurities can be greatly improved along with increase of the temperature of the device, the doping level of the columnar region (4) is relatively reduced, the phenomenon that the avalanche breakdown voltage of the device is reduced caused by load imbalance of the super-junction structure because carriers flow through the epitaxial region (3) is effectively avoided, the operative current range of the device is widened, and the positive safety working area of the device is enlarged.

Description

technical field [0001] The invention belongs to the technical field of power semiconductor devices, and relates to a vertical double-diffused metal oxide semiconductor device (VDMOS device), especially a VDMOS device with a super junction structure (Super Junction). Background technique [0002] At present, the application fields of power semiconductor devices are becoming wider and wider, and can be widely used in DC-DC converters, DC-AC converters, relays, motor drives and other fields. Compared with bipolar transistors, vertical double-diffused metal-oxide-semiconductor field-effect transistors (VDMOS) have the advantages of fast switching speed, low loss, high input impedance, low driving power, good frequency characteristics, and highly linear transconductance. The most widely used new power device at present. However, conventional VDMOS devices also have their inherent disadvantages, that is, the on-resistance increases with the withstand voltage (R on ∝BV 2.5 ) res...

AI Technical Summary

Problems solved by technology

The instantaneous additional carriers introduced by the large current break the charge balance between the p-column region and the n-column region, change the electric field distribution of the withstand voltage layer, and reduce the avalanche breakdown voltage of the device. The large avalanche current that appears in advance will cause the device Temperature rise triggers parasitic effects in the device, causing secondary breakdown and device failure

And the larger the current, the more prone to avalanche breakdown of the device, which limits the forward safe working area of ​​the device

Images