Papers by Keyword: Termination

Abstract: Multilayer ceramic capacitors (MLCC) have wide application in electronic due to its electrical characteristics: low equivalent series resistance (ESR) and high volume efficiency. One of the MLCC manufacturing problems is the choice of composition for the end pastes. The experimental results of the termination pastes composition influence on the quality high-voltage MLCC investigation are presented. The causes of the defects appearance in the termination are determined, the composition of the termination paste, which ensures the quality contact of the internal electrode with the external, is proposed.

Abstract: In this paper, we show state of the art, low on-resistance, 25mW/1.2kV and 43mW/2.5kV SiC MOSFETs with excellent design robustness and process control such that the parametric spread of key device characteristics are approaching Si products. The impact of starting material variability on device performance is shown and design sensitivity curves are presented.

Abstract: In this paper, a 5.7kV 4H-SiC Junction Barrier Schottky diode(JBS) with non-uniform field limiting rings termination is simulated and fabricated successfully based on a epitaxial thickness of 49μm and the doping concentration about 1.04×10¹⁵cm^-3 respectively. The reverse breakdown voltage could reach to 5.7kV at least at reverse current of 200μA. And the on-state voltage is 3V at the forward current of 2A, corresponding to an on-resistance of 32mΩ•cm². The corresponding figure-of- merit of V_B²/ R_SP-ON for our fabricated device is 1.026 GW/cm², which is closing to the optimal levels among several reported SiC JBS.

Abstract: A novel method for analyzing a decrease in breakdown voltage (V_BD) in the termination of 4H-SiC power devices after reverse-bias stressing on the basis of change in depletion-layer capacitance is proposed. Test PN diodes terminated with a junction-termination extension (JTE) were fabricated on n-type 4H-SiC and analyzed by I-V and C-V measurements. According to the results of the measurements, V_BD after stressing decreases, and the capacitance of the test devices decreases after stressing. Measurements with different chip sizes but the same termination width show that the capacitance decrease occurs in the termination area. The simulated capacitance change, on the supposition that positive charge accumulated at the SiO₂/SiC interface, and the measured capacitance change show the same tendency. These results indicate that the origin of V_BD decrease is positive charge accumulated at the SiO₂/SiC interface of the termination after reverse-bias stressing.

Abstract: The static performance of different active and termination area designs for SiC-based Schottky diodes, suitable for 3.3kV applications, were investigated by means of extensive numerical simulations. We found quantitatively that the high electric field of SiC close to avalanche-breakdown is shielded most effectively from the Schottky interface by a trench-based design. Moreover, we conclude that the edge termination design with junction termination extension and four implanted p⁺ guard rings is most robust against oxide interfacial charge.

Abstract: The necessary condition for power devices with enough blocking properties is Junction termination technology. In this paper, starting with the dose of rings, 3.3 kV Floating Filed Rings was investigated, and the influence of electric field and current density on the breakdown characteristic is also described. The results show that the dose of field rings directly affects the stability of breakdown voltage, this impact is relevant to the location of the peak electric field and the peak current density when breakdown was occurred. When the peak electric field appears in the middle of the field rings, the breakdown voltage is not sensitive to the dose of rings; however, when the peak electric field and strongest current density appeared on the edge of termination at the same time, breakdown voltage become very sensitive to the dose of rings because of the highest impact ionization in this position. Simulations and experiments indicate that the junction termination has better withstand voltage stability , when electric field distributes uniformly, the position of breakdown is in the middle of the termination, and the strongest current density appears in the main junction.

Abstract: The 75 m/1.5 kA AC high-temperature superconducting cable(75 m HTS cable) and the 360 m/10 kA DC HTS power cable (10 kA HTS cable), which are supported by Chinese State 863 projects, are both of the demonstration projects facing to industrialization application. The characteristic in structure of warm dielectric (WD) insulated HTS cable is introduced. The electric field distribution characteristic at the cryogenic envelope body, the end-point of metallic shield layer at the end of the HTS cable and the connection sections are analyzed; the controlling method for electric field stress is introduced; there is serious concentration of electric field both in the termination and the connection sections between the termination and the cryogenic envelope. It is difficult to calculate the electric field of the part with irregular or special structure by resolution analytical methods, and the numerical analysis method is effective to analyze the electric field of the shaped structural part for HTS cable. The electric analysis, simulation, the design and processing of insulation for the two cables are finished based upon these two cables run well by now.

Abstract: A novel trench JBS structure has been developed to reduce the electrical field at the Schottky interface. Compared to the conventional planar JBS structure, the new design has reduced the reverse leakage current by 1 order of magnitude at rated voltage. The much reduced field at the Schottky interface allows an increase in the drift doping concentration, which enables a significant chip size reduction on next generation SiC Schottky diodes. This progress makes it possible to fabricate high current rating (>50 A) SiC diodes for module applications.

Abstract: This paper presents results attained with SiC GTO thyristors terminated by a single step and a graded etched JTE. The comparison of both types of devices reveals no significant difference in the on-state and switching characteristics but a higher blocking capability of some thyristors with the latter kind of termination. The best devices showed a forward breakdown voltage of nearly 6 kV, which is a distinct progress as against previous results of thyristors with a graded etched JTE. Furthermore, such GTO thyristors have been characterized dynamically for the first time.

Abstract: In this paper, for the first time, we report 12 kV, 1 cm² SiC GTOs demonstrated with a novel negative bevel termination, which improves the breakdown voltage by >3.5 kV compared to the conventional multiple-zone Junction Termination Extension (JTE). The significant improvement in the blocking voltage was attributed to the elimination of the electrical field crowding in the periphery of the mesa with conventional JTE termination. This new termination has been used in both electrically and optically triggered SiC GTOs. An ultrafast turn-on speed of 70 ns has been measured on 12 kV, 1 cm² SiC light triggered GTOs.