沟槽栅IGBT关键技术研究

Research on the Key Technology of Trench Gate IGBT

与平面栅IGBT相比,沟槽栅IGBT能显著改善通态压降与关断能量的折衷关系,更适用于中低压高频应用领域。针对沟槽栅IGBT技术的挑战(主要包含沟槽刻蚀、栅氧生长、沟槽多晶硅填充等),研究并开发了沟槽栅一系列关键工艺:形貌优良的沟槽槽型,质量完好的栅氧生长工艺以及具备优良均匀性的原位掺杂多晶硅填充工艺等。采用改进工艺后的沟槽栅IGBT芯片具有良好的电学性能,展示出优异的栅氧特性,顺利通过了高温动、静态等多项测试,较平面栅IGBT体现出压降和损耗优势。

Compared with planar IGBT, trench gate IGBT has obviously improved the balance between on-state loss and switching loss and is more suitable to be used in the low-medium voltage and high frequency application field. Aiming at the challenges of the trench gate process include the trench etch processing, gate oxidation, poly filling etc., it researched and developed a series of key processes of trench gate IGBT and then obtained good trench etch profile, an excellent gate oxidation method and good uniformity and integrality of poly filling by amorphous poly doping. With the improved process method, the trench gate IGBT chips had good electrical performances, especially on gate oxidation charactersistic. It passed both static and dynamic tests at high temperature, and reflected obvious advantages at Vceon and power loss when compared to planar IGBT.