垂直氮化镓功率晶体管及其集成电路的发展状况

Recent progress on the vertical GaN power transistor and its integrated circuit

氮化镓作为第三代宽禁带半导体材料的代表之一,因其优越的性能,例如高电子迁移率、高电子饱和速率、耐高温及高热导率等优点吸引了越来越多的关注.也正是因为这些优点,垂直氮化镓功率晶体管在未来的电力电子领域中具有很大的发展和广泛的应用前景.本文列出了氮化镓材料和其他半导体材料主要的物理参数、氮化镓单晶制备及其外延生长的主要方法,阐述了氮化镓功率器件在目前环境下的优势.针对器件结构,列出了横向器件本身存在的问题和垂直器件的优点,解释了垂直器件为何能够成为未来功率器件的主流结构.在此基础上,详细介绍了氮化镓电流孔径垂直晶体管、垂直氮化镓沟槽金属氧化物半导体场效应晶体管、基于原位氧化物氮化镓夹层的垂直沟槽金属氧化物半导体场效应晶体管和垂直氮化镓鳍式场效应晶体管的结构、工作原理、研究进展及所存在的一些问题,并将文中所提及的垂直氮化镓功率晶体管的性能参数按器件种类和时间顺序进行归纳,为未来氮化镓功率晶体管的发展提出了大致的方向.针对集成电路系统,归纳了氮化镓功率器件在驱动芯片方面的特殊要求和关键技术.最后,针对当下的市场环境,列举了垂直氮化镓功率晶体管在中、低压范围内比较热门且发展前景较好的应用场景.

Silicon(Si)material is the mainstream semiconductor material for a long time because of its relatively excellent hightemperature resistance,radiation resistance,low price,and huge reserves.However,with the rapid development of power electronics technology,the development of technology has reached a bottleneck period,and Moore’s law has gradually failed.The existing silicon-based semiconductor devices are close to the theoretical limit of Si materials and can no longer meet the performance requirements of future power devices.However,the cost of transistors is constantly rising,and the performance improvement is slow,gradually moving towards the post-Moore era.To further improve the performance of the device,it is necessary to seek new technologies or new materials to support the continuous development of power devices,and the core of the progress of power semiconductor devices is the development of semiconductor materials.As the third generation of wide band gap semiconductors,gallium nitride(GaN)has been superior to Si in terms of material properties.GaN has the advantages of a wide band gap,high critical field strength,high electron saturation velocity,high conductivity,high-temperature resistance,and high voltage resistance.Compared with traditional Si-based power devices,it not only has higher breakdown voltage,low on-resistance,high electron mobility and good thermal conductivity,but also has smaller device volume and better heat dissipation performance under the same performance,which greatly reduces power consumption and achieves the effect of energy saving and emission reduction.The cost of early GaN single crystal preparation and epitaxial growth is beyond reach.However,with the mature development of growth technology,not only the cost of GaN single crystal substrate and its epitaxial growth is decreasing,but also the quality is gradually increasing,which lays a solid foundation for the wide application of GaN power devices in the future.This paper lists the main physical parameters of GaN and other semiconductor materials,the preparation of GaN single crystal,and the main methods of its epitaxy growth,and describes the advantages of GaN power devices in the current environment.For the device structure,the problems of the lateral device and the advantages of the vertical device are listed,and why the vertical device can become the mainstream structure of future power devices is explained.On this basis,the structure,working principle,research progress,and existing problems of vertical current aperture GaN transistor(CAVET),trench GaN MOSFET,vertical trench MOSFET based on in-situ oxidation GaN interlayer(GaN OG-FET),and vertical GaN fin field effect transistor(GaN FinFET)are introduced in detail.The performance parameters of vertical GaN power transistors mentioned in this paper are summarized in tables according to device types and time sequence,and the general direction of the development of GaN power transistors in the future is proposed.For integrated circuit systems,the special requirements and key technologies of GaN power devices in driver chips are summarized.Finally,for the current market environment,listing the vertical GaN power transistor in the medium and low voltage range is a more popular and promising application scenario.