Superjunction power semiconductor devices: a new milestone in power conversion and control
Publish Time: 2025-03-12
Superjunction power semiconductor devices, as an important type of device with a superjunction voltage-resistant layer, have attracted widespread attention from the industry since their birth due to their unique performance and broad application prospects. This article will explore the concept, mechanism, performance advantages and manufacturing process of superjunction power devices in depth, in order to provide readers with a comprehensive and in-depth understanding.1. Concept and mechanism of superjunction power devicesSuperjunction, also known as superjunction, is an advanced technology for manufacturing power field-effect transistors. Its name first appeared in 1993, but as early as 1988 to 1995, scientists such as Academician Chen Xingbi of the Chinese Academy of Sciences proposed a method to improve the drift layer structure, forming the basic idea of superjunction and applying for corresponding patents. The core of the superjunction structure is to introduce the PN junction into the conventional "resistance-type" voltage-resistant layer, so that it changes qualitatively into a "junction-type voltage-resistant layer". This qualitative change breaks through the "silicon limit" relationship between the on-resistance and voltage resistance of traditional power devices, and achieves a significant improvement in device performance.In the superjunction structure, a significant two-dimensional field effect is introduced inside the voltage-resistant layer. This complex field modulation greatly reduces the peak electric field on the device surface and optimizes the field distribution in the body. This unique electric field modulation mechanism enables superjunction devices to maintain low on-resistance while withstanding high voltage, thereby achieving efficient power conversion.2. Performance advantages of superjunction power devicesAs a typical application of superjunction technology, superjunction power MOSFET has a series of significant performance advantages:High withstand voltage and low on-resistance: The superjunction structure achieves a perfect combination of high withstand voltage and low on-resistance by alternating P-type and N-type columns. This feature enables superjunction power MOSFET to significantly reduce energy loss and improve efficiency in the field of switching power supplies.Fast switching speed: Superjunction power devices have fast switching speeds, which reduces switching time, thereby improving the response speed and stability of the power system.High power output: In the inverter of automotive electronics, superjunction power devices can stably output high power to meet the needs of high-performance power systems such as electric vehicles and hybrid vehicles.Low loss and high efficiency: The conduction loss of superjunction devices is related to the current size, but its channel resistance is low, which reduces the overall loss and improves the efficiency.3. Manufacturing process of superjunction power devicesManufacturing superjunction power devices requires precise lithography and etching processes. At present, the mainstream superjunction power MOSFET processes can be divided into two categories: one is through multiple ion implantation and epitaxy, and the other is deep trench etching and slot filling technology.In the superjunction structure realized by ion implantation, multiple ion implantation and multiple epitaxy processes are required to ensure the depth and high aspect ratio of the superjunction n-type region and p-type region. The process of realizing superjunction power MOSFET through deep trench process is more complicated. It is necessary to epitaxially grow the n- layer on the n+ substrate, then etch to form a deep and steep silicon trench, and then epitaxially fill the p-type silicon to form a superjunction structure.4. Application prospects of superjunction power devicesSuperjunction power devices have attracted much attention due to their excellent performance and wide application prospects. Superjunction power devices play an important role in power conversion in electric vehicle charging facilities, data center power modules, photovoltaic inverters and other fields. At the same time, superjunction power devices also show great application potential in occasions that require high-reliability power supply, such as aerospace power systems and communication base station power supplies.In the future, with the continued growth of markets such as new energy, rail transit, electric vehicles and smart grids, the market demand for superjunction power devices will further expand. At the same time, with the application of new materials and the continuous advancement of manufacturing processes, the performance of superjunction power devices will continue to improve, and the application fields will continue to expand.As a new milestone in power conversion and control, superjunction power semiconductor devices are leading the development trend of power semiconductor devices with their unique performance and broad application prospects. In the future, with the continuous advancement of technology and the continuous expansion of the market, superjunction power devices will surely show their excellent performance and value in more fields.
