• Journal of IKEEE
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• v.14 no.3
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• pp.199-204
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• 2010

In this paper, we proposed trench field ring for breakdown voltage of power devices. The proposed trench field ring was improved 10% efficiency comparing with conventional field ring. we analyzed five parameters of trench field ring for design of trench field ring and carried out 2-D devices simulation and process simulations. That is, we analyzed number of field ring, juction depth, distance of field rings, trench width, doping profield. The proposed trench field ring was better to more 1000V.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.1
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• pp.1-5
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• 2010

In this paper, we proposed trench field ring for breakdown voltage of power devices. The proposed trench field ring was improved 10% efficiency comparing with conventional field ring. we analyzed five parameters of trench field ring for design of trench field ring and carried out 2-D devices simulation and process simulations. That is, we analyzed number of field ring, juction depth, distance of field rings, trench width, doping profield. The proposed trench field ring was better to more 1000 V.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.1995-2003
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• 2014

Power semiconductor devices have been the major backbone for high-power electronic devices. One of important parameters in view of power semiconductor devices often characterize with a high breakdown voltage. Therefore, many efforts have been made, since the development of the Insulated Gate Bipolar Transistor (IGBT), toward having higher level of breakdown voltage, whereby the typical design thereof is focused on the structure using the field ring. In this study, in an attempt to make up more optimized field-ring structure, the characteristics of the field ring were investigated with the use of theoretical arithmetic model and methodologically the design of experiments (DOE). In addition, the IGBT having the field-ring structure was designed via simulation based on the finding from the above, the result of which was also analyzed. Lastly, the current study described the trench field-ring structure taking advantages of trench-etching process having the improved field-ring structure, not as simple as the conventional one. As a result of the simulation, it was found that the improved trench field-ring structure leads to more desirable voltage divider than relying on the conventional field-ring structure.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.3
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• pp.148-151
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• 2017

This research concerns field rings for 3.3kV planar gate power insulated-gate bipolar transistors (IGBTs). We design an optimal field ring for a 3.3kV power IGBT and analyze its electrical characteristics according to field ring parameters. Based on this background, we obtained 3.3kV high breakdown voltage and a 2.9V on state voltage drop. To obtain high breakdown voltage, we confirmed that the field ring count was 23, and we obtained optimal parameters. The gap distance between field rings $13{\mu}m$ and the field ring width was $5{\mu}m$. This design technology will be adapted to field stop IGBTs and super junction IGBTs. The thyristor device for a power conversion switch will be replaced with a super high voltage power IGBT.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1686-1688
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• 1999

The FLR(Field Limiting Ring) structure with a buried ring is proposed to improve breakdown voltage. The breakdown characteristics of proposed structure is verified by two-dimensional device simulator. ATLAS. It has shown that the breakdown voltage of the proposed structure is increased by 11 % compared with that of the FLR.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1337-1339
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• 1998

The trench termination scheme is introduced for high voltage devices. The curvature of the depletion region at field limiting ring is critical factor to determine the breakdown voltage. The smooth curvature of the depletion junction alleviate the electric field crowding effect around this region. In the trench field limiting ring, the radius of the depletion region is smaller than conventional field limiting ring, but the distance between every trench is spaced small enough to punchthrough before initiation of local breakdown. The trench field limiting ring on silicon can ne formed by RIE followed by oxidation on side wall surface of the trench, and polysilicon filling. The combined termination of this trench floating field ring and field plate have been designed and analyzed. The breakdown simulation by 2-dimensional TCAD shows that the cylindrical junction breakdown voltage for substrate doping might be 99 percent of the ideal breakdwon voltage for substrate doping concentration of $3\times10^{14}cm^{-3}$ with about $100{\mu}m$ of lateral termination width.

• Kyungpook Mathematical Journal
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• v.60 no.1
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• pp.53-69
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• 2020

Let (A, M) ⊂ (B, N) be commutative quasi-local rings. We consider the property that there exists a ring D such that A ⊆ D ⊂ B and the extension D ⊂ B is inert. Examples show that the number of such D may be any non-negative integer or infinite. The existence of such D does not imply M ⊆ N. Suppose henceforth that M ⊆ N. If the field extension A/M ⊆ B/N is algebraic, the existence of such D does not imply that B is integral over A (except when B has Krull dimension 0). If A/M ⊆ B/N is a minimal field extension, there exists a unique such D, necessarily given by D = A + N (but it need not be the case that N = MB). The converse fails, even if M = N and B/M is a finite field.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.369-370
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• 2008

This paper describes the electric field distribution of high voltage polymer bushing with inner field shaper designs. The field control can be achieved by means of the designs of such internal field shaper. But high electric stress occurred between field shaper and central conductor by the closely space. In accordance, the floating and ring shield designs was importance for electric stress grading at critical parts of the bushing. The bushing has a central conductor, and internal ring shield or floating shield, gaps are formed between field shaper and ring shield. Accordance equipotential lines extend through gaps. Maxwell 2D simulator based on the boundary element method was also introduced in order to verify the reliability of the polymer bushing.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.10
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• pp.877-882
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• 2005

In order to fabricate a high breakdown SiC-SBD (Schottky barrier diode), we investigate an effect on metal guard ring (MGR) in breakdown characteristics of the SiC-SBD. The breakdown characteristics of MGR-type SiC-SBD is significantly dependent on both the guard ring metal and the alloying time of guard ring metal. The breakdown characteristics of MGR-type SiC-SBDs are essentially improved as the alloying time of guard ring metal is increased. The SiC-SBD without MGR shows less than 200 V breakdown voltage, while the SiC-SBD with Al MGR shows approximately 700 V breakdown voltage. The improvement in breakdown characteristics is attributed to the field edge termination effect by the MGR, which is similar to an implanted guard ring-type SiC-SBD. There are two breakdown origins in the MGR-type SiC-SBD. One is due to a crystal defects, such as micropipes and stacking faults, in the Epi-layers and the SiC substrate, and occurs at a lower electric field. The other is due to the destruction of guard ring metal, which occurs at a higher electric field. The demolition of guard ring metal is due to the electric field concentration at an edge of Schottky contact metal.

• Journal of IKEEE
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• v.11 no.4
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• pp.235-238
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• 2007

The planar edge termination techniques of field-ring and deep junction field-ring were investigated and optimized using a two-dimensional device simulator TMA MEDICI. By trenching the field ring site which would be implanted, a better blocking capability can be obtained. The results show that the p-n junction with deep junction field-ring can accomplish near 30% increase of breakdown voltage in comparison with the conventional field-rings. The deep junctionfield-rings are easy to design and fabricate and consume same area but they are relatively sensitive to surface charge. Extensive device simulations as well as qualitative analyses confirm these conclusions.