Research On Well-shared LIGBT And The Matrix Drive Circuit

SOI(Silicon On Insulator, silicon on insulator) high-voltage power integrated circuits due to their characteristics with low power loss, high speed, and high reliability in recent years, is a hotspot in academic and industrial. SOI-based high-voltage power integrated circuits can easily integrate the LIGBT(Lateral Insulation Gate Bipolor Transistor), which has both the strong current capability from BJT(Bipolar Junction Transistor) and high switching speed from LDMOS(Lateral Double-diffused Metal Oxide Semicondutor). The high-voltage power integrated circuits are so important that are widely used in smart appliances, smart home, automotive electronics, lighting and other fields. How to make high performance, high reliability and cost-efficient of SOI high-voltage power integrated circuits attracts attention from many researchers.This paper focuses on research which include the high performance, high reliability and low cost of the SOI LIGBT device and related circuits. Proposed a well-shared SOI LIGBT technology which maintaining high-performance and get the simplified process. Presents a low harmonic current output mode, reducing low-frequency radiated EMI(Electromagnetic Interference) of multi-channel power driver IC. A matrix-drive approach which replaced the traditional linear drive can save the chip area significantly, and finally presents the actual tests and production certification.Major Innovation and Working are as follows:(1) A well-shared SOI LIGBT is proposed to simplify device fabrication process. By sharing the the N-well of CMOS and independent N-buffer of original LIGBT, optimal works are implemented about device structure and process parameters under the new conditions. Experimental results show that the off-state breakdown voltage of the well-shared SOI LIGBT reaches 218 V, the on-state breakdown voltage reaches 170 V, maintaining the equivalent characteristics with the original device.(2) Based on SOI LIGBT device and drive method, a low harmonic output current mode is proposed. Research on excessive low frequency radiated EMI, according to the SOI LIGBT characteristics and adjust gate drive current capability, using the method of spreading processing, control and reduction about the peak current crosstalk between the high and low voltage, ultimately reduce the harmonics between 30 MHz ~ 50 MHz, the radiation of quasi-peak has declined from 47 dBμV / m to 36.8 dBμV / m.(3) Based on SOI LIGBT circuit and load type, a matrix-drive structure is proposed alternative to traditional linear drive structure, combined with characteristics from the capacitance load, the SOI LIGBT level-shifted circuits are reduced from 96 to 22, the total chip area will eventually cutted down from 20 mm2 to 11.6 mm2.(4) Research on the process of SOI LIGBT and circuit reliability tests and certification, through the combined process about low-voltage CMOS and high voltage devices, the process obtained the enough tolerance range. Besides, the Walk-out phenomenon under the breakdown test is analyzed and the solution is proposed. According to the charactics scan driver IC in the plasma display panel, the tests and certification for the LIGBT devices and circuits are elaborated, and ultimately achieve a mass production over 150 K.