Byeong-Hoon Lee

A new gradual hole injection dual-gate LIGBT

A new shorted-anode lateral insulated gate bipolar transistor (SA-LIGBT), entitled gradual hole injection dual gate LIGBT (GHI-LIGBT), is proposed and fabricated. The new device employs a dual gate and p/sup +/ injector in order to initiate the hole injection gradually from the anode electrode into the drift region so that the negative differential resistance (NDR) regime may be eliminated. The experimental results show that the NDR regime, which may cause undesirable device characteristics, is completely eliminated in the GHI-LIGBT, and the forward voltage drop is reduced by 1 V at the current density of 200 A/cm/sup 2/ in comparison with the conventional SA-LIGBT.A new shorted-anode lateral insulated gate bipolar transistor (SA-LIGBT), entitled gradual hole injection dual gate LIGBT (GHI-LIGBT), is proposed and fabricated. The new device employs a dual gate and p/sup +/ injector in order to initiate the hole injection gradually from the anode electrode into the drift region so that the negative differential resistance (NDR) regime may be eliminated. The experimental results show that the NDR regime, which may cause undesirable device characteristics, is completely eliminated in the GHI-LIGBT, and the forward voltage drop is reduced by 1 V at the current density of 200 A/cm/sup 2/ in comparison with the conventional SA-LIGBT.

Latch-up Suppressed Insulated Gate Bipolar Transistor by the Deep p^+ Ion Implantation under the n^+ Source

A novel insulated gate bipolar transistor (IGBT) structure, which employs the self aligned deep p+ buried region enveloping all the area under the n+ source, is proposed and verified by SUPREM IV and PISCES-IIB simulation. The simulation results show that the latch-up current is found to increase up to about 10 times compared with the conventional structure when the implantation dose of the p+ buried region and the p-body are 1×1015 cm-2 and 1×1014 cm-2, respectively. The variation of the threshold voltage is within 0.1 V although the implantation dose of the p+ buried region increases from 1×1014 cm-2 to 1×1015 cm-2.

Dual-gate shorted-anode LIGBT with p/sup +/ injector eliminating the negative resistance regime

A new shorted-anode lateral IGBT with dual gate and p/sup +/ injector (DG-SALIGBT) is proposed and fabricated in order to eliminate the negative differential resistance (NDR) regime, which is the inherent characteristic of SALIGBTs, by modulating the drift region conductivity gradually. The experimental results show that the NDR regime is eliminated completely and the forward voltage drop is reduced considerably in the DG-SALIGBT when compared with the conventional SALIGBT, without sacrificing the switching speed. We have analyzed the device operation mechanism, such as hole injection phenomena, by 2D numerical simulation.

Analysis of dual-gate LIGBT with gradual hole injection

The device characteristics of a gradual hole injection dual-gate lateral insulated gate bipolar transistor (GHI-LIGBT) is analyzed with the experiment and two-dimensional (2-D) numerical simulation. The hole injection mechanism in the GHI-LIGBT is investigated in detail and the device characteristics of the GHI-LIGBT are studied in terms of the various device parameters such as the p/sup +/ injector length and the injection gate length. The hole injection characteristics and latch-up characteristics in the GHI-LIGBT are also presented as a function of temperature. The experimental results demonstrate that an on-state voltage drop in GHI-LIGBT is reduced by 1 V, compared with the conventional SA-LIGBT and the negative resistance regime is eliminated since the injection of holes is initiated at the lower anode voltage. It is also found that the low on-state voltage drop in the GHI-LIGBT can be achieved without sacrificing the inherent high switching speed in shorted anode (SA) LIGBT structures.

CB-BRT: a new base resistance-controlled thyristor employing a self-aligned corrugated p-base

We propose and fabricate a new base resistance-controlled thyristor (BKT) employing a self-aligned corrugated p-base. The new device, entitled CB-BRT, suppresses the snap-back effectively and increases the maximum controllable current. Experimental results show that the snap-back of the CB-BRT is reduced significantly when compared with that of the conventional BRT. Also, the maximum controllable current of the CB-BRT increases as compared with the conventional BRT.We propose and fabricate a new base resistance-controlled thyristor (BKT) employing a self-aligned corrugated p-base. The new device, entitled CB-BRT, suppresses the snap-back effectively and increases the maximum controllable current. Experimental results show that the snap-back of the CB-BRT is reduced significantly when compared with that of the conventional BRT. Also, the maximum controllable current of the CB-BRT increases as compared with the conventional BRT.

The separated shorted-anode insulated gate bipolar transistor with the suppressed negative differential resistance regime

The separated shorted-anode LIGBT (SSA-LIGBT), which suppresses effectively the negative differential resistance regime, is investigated by performing 2-dimensional numerical simulation. In order to suppress the negative differential resistance regime, the SSA-LIGBT increases the pinch resistance by employing the highly resistive n-drift region as an electron conduction path instead of the lowly resistive n buffer region of the conventional SA-LIGBT. The SSA-LIGBT shows the remarkably decreased forward voltage drop when compared with the conventional SA-LIGBT and shows the one-order faster turn-off time than that of the LIGBT.

An insulated gate bipolar transistor employing the plugged n+ anode

A vertical Insulated Gate Bipolar Transistor, entitled CB-IGBT(Carrier-inducing Barrier-controlled IGBT) has been proposed and verified by a two-dimensional numerical simulation. The structure of the proposed device is almost identical with that of the conventional IGBT, except for the anode structure in which the p-barrier region and n+ anode region are employed. In the CB-IGBT, the potential barrier height at the junction between the p-barrier region and n-drift region is controlled by the amount of carriers, so that the trade-off relation between the on-state voltage drop and the switching speed is decoupled efficiently. The switching speed of CB-IGBT is so much enhanced with a negligible increase of the on-state voltage drop, since electrons stored in the n-drift region can be extracted rapidly into the n+ anode via p-barrier region during turn-off process.

A dual-gate shorted-anode silicon-on-insulator lateral insulated gate bipolar transistor with floating ohmic contact for suppressing snapback and fast switching characteristics

Abstract A new dual-gate shorted-anode SOI (silicon-on-insulator) LIGBT (lateral insulated gate bipolar transistor), which suppresses the snapback effectively with gates signal of the same polarity, is proposed and verified by numerical simulation. The suppression of the snapback in I–V characteristics is obtained by initiating the hole injection by employing the dual gate and FOC (floating ohmic contact) in the new device. The proposed device eliminates the snapback completely and has a low forward voltage drop compared with conventional SA-LIGBT (shorted anode lateral insulated gate bipolar transistor). Snapback of SA-LIGBT occurs at anode voltage 11xa0V, but in case of the proposed device, the snapback phenomenon is completely eliminated. Also, by employing the FOC, the drive signals of two gates are of an identical polarity. Therefore the proposed device requires no additional power supply, which is a necessity for driving conventional dual-gate SA-LIGBT.

The modified HSINFET using the trenched JBS injector

A Hybrid Schottky INjector Field Effect Transistor (HSINFET) which increases the forward conduction current without sacrificing the latch-up capability and turn-off characteristics, is proposed. The feature of the structure is that the hybrid Schottky injector is implemented by the trench sidewall Schottky contact and p-n junction injector at the bottom of a trench. The device characteristics of the proposed HSINFET are numerically simulated and compared with conventional devices. The proposed HSINFET exhibits a lower forward voltage drop than the conventional HSINFET by 0.4 V at 100 A/cm/sup 2/.

Latch-up Suppressed IGBT by the Deep P+ Ion Implantation under the n+ Source

A novel IGBT stmchrre, which employs the self alisned deep p+ buried region enveloping all the area under the n+ source, is proposed and verifed by SIIPREM4 and PISCES-2B simulation. The latch-up current of the proposed device is found to increase with the ion implantation dose nnd the latch up current increases up about 10 times compared with the coventional stmchrre when the implantation dose of the p+ buried region and the p-body is ltldscm-z and lxlda cm-z, respectively. It should be noted that the variation of tle threshold voltage is within 0.1V although the implantation dose of the p+ buried region increases from lxlda cm-Z to 1x1d5 cm-2.