Dielectric isolation and junction isolation combined LIGBT (Lateral Insulated Gate Bipolar Transistor) device and manufacturing method

Abstract

The invention relates to a dielectric isolation and junction isolation combined LIGBT (Lateral Insulated Gate Bipolar Transistor) device and a manufacturing method and belongs to the technical field of electronics. According to the LIGBT device, for an anode area of the traditional short-circuit LIGBT, a dielectric isolation and junction isolation combined structure is adopted, dielectric isolation is adopted between N+ and P+ of an anode, and junction isolation is adopted below N+. According to the novel dielectric isolation and junction isolation combined structure, on one hand, on the basis that shorter off time of the device is guaranteed, during conduction, the negative resistance effect of the negative resistance effect can be eliminated and the performance and the stability of the device are improved, and on the other hand, the size area of the device can also be reduced.

Description

technical field [0001] The invention relates to a LIGBT device combined with dielectric isolation and junction isolation and a manufacturing method, belonging to the field of electronic technology. Background technique [0002] Lateral Insulator Gate Bipolar Transistor LIGBT (Lateral Insulator Gate Bipolar Transistor) is a composite power device combined with a MOS gate device structure and a bipolar transistor structure. It has the characteristics of high input impedance and low conduction voltage drop. The difference from LDMOS is that LIGBT is a bipolar device. When it is turned on, there is not only electron current, but the anode P+ will inject holes into the drift region to generate electron current, which makes the turn-off time longer. Generally, the anode short-circuit structure that reduces the turn-off time can provide an electron extraction channel when the device is turned off, but there is a process of transition from LDMOS mode to LIGBT mode when the device is...

AI Technical Summary

Problems solved by technology

The difference from LDMOS is that LIGBT is a bipolar device. When it is turned on, there is not only electron current, but the anode P+ will inject holes into the drift region to generate electron current, which makes the turn-off time longer.

Generally, the anode short-circuit structure that reduces the turn-off time can provide an electron extraction channel when the device is turned off, but there is a process of transition from LDMOS mode to LIGBT mode when the device is turned on, which brings negative resistance effect and affects the stability of the device.

Dielectrically isolated LIGBT can suppress the negative resistance effect, but because of the depth and width of the dielectric trench, the size of the device will become larger

The separated structure of the anode P+ and N+ can also suppress the negative resistance effect, but also the overall size of the device becomes larger due to the distance between the two

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