Development of an innovative n-LD-MOSFET in BCD10 technology

Nowadays, more and more electronic systems and applications fields, ranging from the automotive sector, energy management and distribution to IT and consumer industry, require devices with the ability to drive high current loads along with the ability to sustain a high voltage drop, both when they are ON and OFF. Furthermore, the need for a very small power dissipation is becoming rapidly a crucial point in the design of new transistors or complex systems. As a consequence, it is necessary firstly, to increase the power transfer efficiency and, secondly, to limit the heat generation. Integrated power transistors are born with the idea of combining all these requirements to have the best trade-off among high current, low ON Resistance, wide operating frequency range, low static consumption, good thermal stability, high reliability, and small size. In the last 30 years, the market demands showed an unstopped growth due to the increase in the number of interested fields, produced units, and of new complex and powerful applications with higher power demand. Consequently, the research has investigated new roads. New substrate materials have been studied like GaN (Gallium Nitride) for optoelectronic, high power and/or high-frequency applications, SiC (Silicon Carbide) for high power and/or high-temperature applications, GaAs (Gallium Arsenide) for microwave applications, and many other III-V compounds. Materials that have a higher band-gap to provide high voltage breakdown, lower ON resistance and, in the end, a much lower power dissipation. At the same time, new device architectures have been attempted and structures like Vertical Diffused MOSFET (VD-MOSFET) or Isolated Gate Bipolar Transistor (IGBT) have been introduced in business and optimized massively. Similar efforts have been applied to find solutions to integrate power MOSFETs into a Smart Power platform such as BCD (Bipolar-CMOS-DMOS) technology. The integration of power MOSFETs in advanced technology nodes was driven by the needs to integrate denser digital cores for signal and data processing. It had to face and overcome many challenges concerning the limitations coming from the scaling of some critical dimensions (oxide thickness, spacer dimension). Contrary to the digital section, the power section does not follow the scaling of the operating voltages and its integration in advanced technology nodes could penalize the performance of the existing solutions. Therefore, this work will be dedicated to the study of a new LD-MOSFET architecture intended for low-voltage applications (up to 30V) aimed to overcome these limitations. With these objectives, an all-in-active LD-MOSFET will be combined with metal field plate technology to obtain new devices with higher possibilities to be technologically and economically competitive. Studies, analysis, simulations, and experimental measurements will be reported and detailed in order to characterize this innovative solution.