金刚石具有宽带隙(5.47 eV)、高载流子迁移率(空穴3 800 cm2/(V·s)、电子4 500 cm2/(V·s))、高热导率(22 W·cm-1·K-1)、高临界击穿场强(>10 MV/cm), 以及最优的Baliga器件品质因子, 使得金刚石半导体器件在高温、高频、高功率, 以及抗辐照等极端条件下有良好的应用前景。随着单晶金刚石CVD生长技术和p型掺杂的突破, 以硼掺杂金刚石为主的肖特基二极管(SBD)的研究广泛展开。本文详细介绍了金刚石SBD的工作原理, 探讨了高掺杂p型厚膜、低掺杂漂移区p型薄膜的生长工艺, 研究了不同金属与金刚石形成欧姆接触、肖特基接触的条件, 分析了横向、垂直、准垂直器件结构的制备工艺, 以及不同结构对SBD正向、反向、击穿特性的影响, 阐述了场板、钝化层、边缘终端等器件结构对SBD内部电场的调制作用, 进而提升器件反向击穿电压, 最后总结了金刚石SBD的应用前景及面临的挑战。

Diamond has excellent material properties such as wide band gap (5.47 eV), high carrier mobility (3 800 cm2/(V·s) for holes and 4 500 cm2/(V·s) for electrons), high thermal conductivity (22 W·cm-1·K-1), high critical breakdown field strength (>10 MV/cm), and optimal Baliga’s figure of merit, which make diamond semiconductor devices ideal choices for the applications in extreme conditions such as high temperature, high frequency, high power, and strong irradiation. With the breakthroughs in diamond crystal growth by CVD techniques and p-type doping of diamond crystal, research on Schottky barrier diode (SBD) based on boron-doped diamond has been widely carried out. In this review, the working principles of the diamond SBD are introduced in detail. The growth processes of highly doped p-type thick films, p-type films of low doping drift region are investigated, and the conditions for the formation of ohmic contact and Schottky contact between different metals and diamond crystals are studied. Then the preparation processes of transverse, vertical and pseudo-vertical device structures and their effect on forward, reverse and breakdown characteristics of the SBDs are analyzed. The modulation of the internal electric field of SBDs by device structures like field plate, passivation layer and edge terminal, which strengthens the reverse breakdown voltage of the device, is illustrated. Finally, the application prospects and challenges of diamond SBDs are summarized.