• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.2
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• pp.63-66
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• 2017

This research was about shielded trench gate power MOSFET for low voltage and high speed. We used T-CAD tool and carried out process and device simulation for exracting design and process parameters. The exracted parameters was used to design shieled and conventional trench gate power MOSFET. And The electrical characteristics of shieled and conventional trench gate power MOSFET were compared and analyzed for their power device applications. As a result of analyzing electrical characteristics, the recorded breakdown voltages of both devices were around 120 V. The electric distributions of shielded and conventional trench gate power MOSFET was different. But due to the low voltage level, the breakdown voltage was almost same. And the other hand, the threshold voltage characteristics of shielded trench gate power MOSFET was superior to convention trench gate power MOSFET. In terms of on resistance characteristics, we obtained optimal oxied thickness of $3{\mu}m$.

• Journal of IKEEE
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• v.16 no.4
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• pp.283-289
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• 2012

In this paper, We proposed Separate Gate Technique(SGT) to improve the switching characteristics of Trench power MOSFET. Low gate-to-drain 전하 (Miller 전하 : Qgd) has to be achieved to improve the switching characteristics of Trench power MOSFET. A thin poly-silicon deposition is processed to form side wall which is used as gate and thus, it has thinner gate compared to the gate of conventional Trench MOSFET. The reduction of the overlapped area between the gate and the drain decreases the overlapped charge, and the performance of the proposed device is compared to the conventional Trench MOSFET using Silvaco T-CAD. Ciss(input capacitance : Cgs+Cgd), Coss(output capacitance : Cgd+Cds) and Crss(reverse recovery capacitance : Cgd) are reduced to 14.3%, 23% and 30% respectively. To confirm the reduction effect of capacitance, the characteristics of inverter circuit is comprised. Consequently, the reverse recovery time is reduced by 28%. The proposed device can be fabricated with convetional processes without any electrical property degradation compare to conventional device.

• Journal of IKEEE
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• v.25 no.1
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• pp.15-24
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• 2021

In this paper, 1700 V EPDT (Extended P+ shielding floating gate Double Trench) MOSFET structure, which has a smaller switching time and loss than CDT (Conventional Double Trench) MOSFET, is proposed. The proposed EPDT MOSFET structure extended the P+ shielding area of the source trench in the CDT MOSFET structure and divided the gate into N+ and floating P- polysilicon gate. By comparing the two structures through Sentaurus TCAD simulation, the on-resistance was almost unchanged, but Crss (Gate-Drain Capacitance) decreased by 32.54 % and 65.5 %, when 0 V and 7 V was applied to the gate respectively. Therefore, the switching time and loss were reduced by 45 %, 32.6 % respectively, which shows that switching performance was greatly improved.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.3
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• pp.263-267
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• 2014

Super junction trench gate power MOSFETs have been receiving attention in terms of the trade-off between breakdown voltage and on-resistance. The vertical structure of super junction trench gate power MOSFETs allows the on-resistance to be reduced compared with conventional Trench Gate Power MOSFETs. The heat release of devices is also decreased with the reduction of on-resistance. In this paper, Lattice Temperature of two devices, Trench Gate Power MOSFET and Super junction trench gate power MOSFET, are compared in several temperature circumstance with the same Breakdown Voltage and Cell-pitch. The devices were designed by 100V Breakdown voltage and measured from 250K Lattice Temperature. We have tried to investigate how much temperature rise in the same condition. According as temperature gap between top of devices and bottom of devices, Super junction trench gate power MOSFET has a tendency to generate lower heat release than Trench Gate Power MOSFET. This means that Super junction trench gate power MOSFET is superior for wide-temperature range operation. When trench etching process is applied for making P-pillar region, trench angle factor is also important component. Depending on trench angle, characteristics of Super junction device are changed. In this paper, we focus temperature characteristic as changing trench angle factor. Consequently, Trench angle factor don't have a great effect on temperature change.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.10
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• pp.713-719
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• 2013

Power MOSFET operate voltage-driven devices, design to control the large power switching device for power supply, converter, motor control, etc. We have optimal designed planar and trench gate power MOSFET for high breakdown voltage and low on resistance. When we have designed $6,580{\mu}m{\times}5,680{\mu}m$ of chip size and 20 A current, on resistance of trench gate power MOSFET was low than planar gate power MOSFET. The on state voltage of trench gate power MOSFET was improved from 4.35 V to 3.7 V. At the same time, we have designed unified field limit ring for trench gate power MOFET. It is Junction Termination Edge type. As a result, we have obtained chip shrink effect and low on resistance because conventional field limit ring was convert to unify.

• Journal of the Korean Vacuum Society
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• v.11 no.4
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• pp.212-217
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• 2002

A new technique for highly controllable trench corner rounding at the top and bottom of the trench using pull-back and hydrogen annealing has been developed and investigated. The pull-back process could control the trench corner rounding radius at the top comers of the trench. The silicon migration generated by hydrogen annealing at the trench coiners provided (111) and (311) crystal planes and gave a uniform gate-oxide thickness, resulting in high reliable trench DMOSFETs with highly breakdown voltages and low leakage currents. The breakdown voltage of a trench DMOSFET fabricated using hydrogen annealing was increased by 25% compared with a conventional DMOSFET. The reasonable drain current of 45.3 A was obtained when a gate voltage of 10 V was supplied. The on-resistance of the trench gate DMOSFET fabricated using the trench cell of 45,000 was about 55 m(at a gate voltage of 10 V under a drain current of 5 A.

• ETRI Journal
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• v.35 no.4
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• pp.632-637
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• 2013

In this paper, we propose a superjunction trench gate MOSFET (SJ TGMOSFET) fabricated through a simple p-pillar forming process using deep trench and boron silicate glass doping process technology to reduce the process complexity. Throughout the various boron doping experiments, as well as the process simulations, we optimize the process conditions related with the p-pillar depth, lateral boron doping concentration, and diffusion temperature. Compared with a conventional TGMOSFET, the potential of the SJ TGMOSFET is more uniformly distributed and widely spread in the bulk region of the n-drift layer due to the trenched p-pillar. The measured breakdown voltage of the SJ TGMOSFET is at least 28% more than that of a conventional device.

• ETRI Journal
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• v.36 no.5
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• pp.829-834
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• 2014

In this paper, a lateral power metal-oxide-semiconductor field-effect transistor with ultra-low specific on-resistance is proposed to be applied to a high-voltage (up to 200 V) integrated chip. The proposed structure has two characteristics. Firstly, a high level of drift doping concentration can be kept because a tilt-implanted p-drift layer assists in the full depletion of the n-drift region. Secondly, charge imbalance is avoided by an extended trench gate, which suppresses the trench corner effect occurring in the n-drift region and helps achieve a high breakdown voltage (BV). Compared to a conventional trench gate, the simulation result shows a 37.5% decrease in $R_{on.sp}$ and a 16% improvement in BV.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.3
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• pp.259-266
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• 2004

In this paper. a new two types of EST(Emitter Switched Thyristor) structures are proposed to improve the electrical characteristics including the current saturation capability. Besides, the two dimensional numerical simulations were carried out using MEDICI to verify the validity of the device and examine the electrical characteristics. First, a vortical trench electrode EST device is proposed to improve snap-back effect and its blocking voltage. Second, a dual trench gate EST device is proposed to obtain high voltage current saturation characteristics and high blocking voltage and to eliminate snap-back effect. The two proposed devices have superior electrical characteristics when compared to conventional devices. In the vertical trench electrode EST, the snap-back effect is considerably improved by using the vertical trench gate and cathode electrode and the blocking voltage is one times better than that of the conventional EST. And in the dual trench gate EST, the snap-back effect is completely removed by using the series turn-on and turn-off MOSFET and the blocking voltage is one times better than that of the conventional EST. Especially current saturation capability is three times better than that of the other EST.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.392-395
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• 2003

For the first time, the new dual trench gate Emitter Switched Thyristor is proposed for eliminating snap-back effect which leads to a lot of serious problems of device applications. Also, the parasitic thyristor that is inherent in the conventional EST is completely eliminated in the proposed EST structure, allowing higher maximum controllable current densities for ESTs. Moreover, the new dual trench gate allows homogenous current distribution throughout device and preserves the unique feature of the gate controlled current saturation of the thyristor current. The conventional EST exhibits snap-back with the anode voltage and current density 2.73V and $354/{\S}^2$, respectively. But the proposed EST exhibits snap-back with the anode voltage and current density 0.93V and $58A/{\S}^2$, respectively. Saturation current density of the proposed EST at anode voltage 6.11V is $3797A/{\S}^2$. The characteristics of 700V forward blocking of the proposed EST obtained from two dimensional numerical simulations (MEDICI) is described and compared with that of the conventional EST.